Transcript Biology 112 Aims Community College Instructor ~Leba

Biology 112
Aims Community College
Instructor ~Leba Sarkis
Created by Josh Dewey
Chapter 22
Evolution
• Evolution = the modification of species
over time
• Populations= a group of interbreeding
individuals belonging to a particular species
in a certain geographical area.
Chapter 22
Evolution
Charles Darwin wrote Origin of the Species in 1859 (Natural selection)
• Evidence of Evolution
• 1.
Biogeography ~ life based on it’s location. Ex- environmental factors
• 2.
Fossil record progression. Ex- fish> amphibians> reptiles> birds>
mammals
• 3. Taxonomy ~ classification
• 4.
Comparative anatomy. Ex-snakes having remnants of leg appendages
• 5.
Comparative embryology
a. Ontogeny Recapitulate Phylogeny~ embryonic development replays
evolutionary history.
Molecular biology- genetics patterns and variations.
Chapter 22
Evolution
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Carlos Linnaeus is credited with the creation of the binomial system of classification; he used two
words to describe organisms “Genus” and “Species”
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Kingdom, Phylum, Class, Order, Family, Genus, Species
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Cuvier Paleontologist (the study of fossils) fossils are defined as impressions or relics of an organism
that once lived. Now sealed in the rock.
~ Two categories Flora-plants
Fauna – animals
Theory of catastrophism: is due to devastation that buried cities, animals and plants that preserved
living organisms.
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Theory of gradualism: explains or supports Cuvier’s view. James Hutton: Believed that form over a
period of time gradually.
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Theory of Uniformitarism: (Lyell) He added to the idea of Gradualism. States that the same forces
that form mountains, rivers also does so in reverse.
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Geographical Theory of Uniformitarianism: The earth’s surface was formed over long periods of time
by slow geological processes of volcanism, uplift, erosion, and glaciation. (Charles Lyell).
Chapter 23
Evolution
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Species~ organisms capable of interbreeding
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Biological concept (1940) Proposed by Mayr
Organisms that don’t interbreed Ex- mule. An species in its own, but doesn’t reproduce.
Gene pool- a total aggregate of species at one time
Microevolution – a small change of genetic traits/ materials over time.
Gene frequency – prediction of gene frequency if a population is not changing and at equilibrium.
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1.
Genetic Drift- change in a population due to chance
a.
b.
2.
3.
4.
Bottleneck effect- reduction of pop due to chance
Founder effect- moving into a new area/environment causing change.
Gene Flow – migration or immigration (planned) not by chance
Mutation (error in DNA)- the original source of genetic variation Ex- substitution, deletion, addition.
Non-random mating
a.
b.
5.
Changes is microevolution
Inbreeding – breeding with the local population
Assortive mating- when physical characteristics are a factor in the selection process.
Natural Selection- survival of the fittest
a.
b.
In good physical shape
The ability to reproduce
Chapter 23
Evolution
1.
Contributions for Species variations
Barriers- reproductive (mule) and environmental (mountains)
a.
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b.
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c.
Prezycotic- the species is stopped prior to zygote formation.
a.
Ecological. Ex- Gardner snakes, some live in water, some live on land. The two do not mate
because of their habitat.
b. Temporal- two species that live in the same environment but mate at different times, so they
never mate together. Ex- rainbow trout and brown trout.
c.
Behavioral- species can’t understand each other’s signals, calls and smells. So they don’t mate.
d. Mechanical- Anatomical differences. Ex- appendages of the males may not fit between species.
e.
Gametic- gametes can’t co9me together possibly because the environment of the female is too
acidic for the sperm to survive in.
Postzycotic
a.
Hybrid Inviability- two species will hybridize but a zygote doesn’t develop.
b. Hybrid Steriability- two species will mate but their offspring are sterile. Ex- Horse and Donkey
= Mule
c.
Hybrid Breakdown- two species that breed will produce one generation that can breed with one
another but the second generation is sterile.
Introgression- two distinct species mate and are fertile, have offspring, some but not all of their
alleles will manage to get passed on. Offspring mates with the parents. Ex-corn. Some corn is crossed
with grass- only happens in plants.
Chapter 23
Evolution
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Two Speciations That Occur
1. Sympatric Speciation- Formation of a new species within a certain range of their parents. Two
species with overlapping ranges (Geographical area)
2. Allopatric Speciation- when a species arises and develop outside the range of their parents.
Species get separated. Ex- the finches of Darwin from the Galapagos Islands.
Phylogoney- evolutionary history of organisms or life
Systematics - branch of biology concerned with the diversity of life.
Macroevolution- is the origin of taxonomic groups higher that the species level. Implies the
substantial change in organisms.
Anytime you have the scientific name of a species you use the genus and species. Genus is
capitalized. Written in italics or underlined. Ex- Homo sapiens
There are two schools of taxonomy
1. Phenetic – put the greater emphasis on anatomical characteristics and similarities.
2. Cladistic – the individuals that uses time to classify organisms based on the phylogenetic tree.
Classical Evolutionary School – take the best of both phenetic and cladistic.
Chapter 24
Evolution
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Big bang theory- matter blew apart 20 billion years ago. The sun formed 5 billion years
ago from matter in the center. The matter in the periphery formed the planets including
earth 4.5 billion years ago.
Hot H2 formed the early atmosphere (there is no free oxygen in the early atmosphere).
(H2=>H20, CO2, CO, N2, Ch4, NH3) all comprised to form the early atmosphere.
Stanley Miller and Harold Urey collected water, methane and ammonia in a flask
through which they sent an electrical current to simulate the early volcanic and lightning
activity. This action turned the mixture into organic matter an amino acids (monomers)
into polymers through dehydration synthesis. Polymers were created as proteins or
polypeptides. They then took the amino acids and dripped them into clay or hot lava in
the presence of iron or zinc. This process is dehydration synthesis of monomers to
polymers the catalyst being iron and zinc.
Chapter 24
Evolution
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Evidence For Early Life
1. Stromalites – banded sediment formed 3.5 billion years ago like the jelly like coats of some of
today’s bacteria.
a. The record of the oldest fossils (3.5 billion years)
2. Protobionts – molecular aggregates with chemical characteristics different with their
surroundings. Meaning (emergent properties) or abiotically produced molecules exhibiting some life
properties referred to as predecessors to true cells. They exhibit metabolism and excitability. They do
not however exhibit reproduction.
3. Protenoids (proteins or polymers)
4. Microspheres Formation – droplets of polypeptides that form in cool water. Microspheres have
selective permeable membranes. Comes from liposomes, droplets like from lipids, orient into a cell
membrane.
5. Coacervates – colloidal drops of amino acids, polypeptides, nucleic acids, and polysaccharides
that will self assemble.
6. Formation of Protobionts – exhibit some properties of life this is the origin of life on earth
(bacteria). This cannot be done in today’s present atmosphere because of the presence of oxygen.
Chapter 24
Evolution
Living organisms
Prokaryotic
Eukaryotic
Monera
Simple multi-celled
Multi celled
Or single celled organisms
Protista
Autotrophic
(Photosynthetic) Plants
Absorptive Nutrition
Fungi
Heterotrophic
(Carnivores)
Ingestive Nutrition
Animals
Chapter 40
Tissues
1.
a.
Tissues
Epithelium- (above) (layers) skin or lining of organs
Function: Secretion- sweat or oil, absorption
~Simple-one layer
~Stratified- more than one layer
Squamous- flat, scale like shape
a.
b.
b.
Columnar- Function: absorption and secretion
a.
b.
c.
c.
d.
Simple- lens of the eye, alveoli, have an absorption function: absorbs light, air, ect.
Stratified- like skin, provides abrasive protection
Simple – single celled, (ciliated) which facilitates movement of particles or fluid through a space.
Stratified- multi-celled
Pseudostratified- columnar cells (lines the trachea)
Transitional- can easily stretch, found in bladder, multi- layered
Cubodial
a.
b.
Simple- found in kidney tubules
Stratified- found in sweat glands
Chapter 40
Tissues
Muscles
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a.
Skeletal- multi-nucleated, striated, voluntary, cylindrical
b. Cardiac- single nucleus, striated, non-voluntary, branched, intercalated disks, relay impulses between muscle cells
c.
Smooth or Visceral
Single nucleus, no striations, non-voluntary, spindle shape, have flattened nucleus
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Terms
Sarcomere: the basic functional unit of a muscle cell or of a contraction
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Peristalysis: the wavelike notion of smooth muscle moving the food down the esophagus (example= a rhythm of a snake).
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Diaphragm: a muscle that aids in breathing, runs from the thoracic cavity to the abdominal cavity
Tissue
Multi nucleus
Striated
Voluntary
Skeletal
Yes
Yes
Yes
Smooth
No
No
No
Cardiac
No
Yes
No
Chapter 40
Tissues
Connective tissues
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a.
Loose or Areolar- elastic and collagenous fibers- the most abundant
b. Dense- made of collagenous (tough) fibers densely packed.
Found in: Ligaments- bone to bone (joint) connections
Tendons- connecting muscle to bone
Fascia- tie all tissue together
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e.
a.
b.
c.
d.
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c.
d.
a.
b.
Cartilage- Hyaline (in trachea), elastic (ear and nose), and fibro (in the inner-vertebral discs)
Bone- Osteocyte cell located within the Lacuna
Spongy or Cancellous- osteocytes and Lacuna spread out with no particular pattern- found in the heads of the long bone.
Compact- shaft of bone- has a special arrangement called the Hversion system or Osteon.
Blood
RBC: (erythrocytes) function is the carrying of 02 via hemoglobin
WBC: (leukocytes) function is phagocytosis
Platelets: (trombocytes) performs the function of clotting
Plasma: the liquid portion of blood
Scerum- the plasma minus the clotting factors (proteins, not cells are the clotting factors)
f. Adipose Tissue (fat)- functions in insulation and storage of energy
g. Nervous
a. Neuron- the basic anatomical and functional unit of the nervous tissue. The neuron is made up of the Axon (white matter) the Dendrites,
the soma of body (gray mater) and a covering of the axon called the Myelin sheath (appears white). The direction of an impulse travels from
the Dendrite > Soma > Axon.
Chapter 41
Nutrition
Nutrition
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Holotroph - organisms that ingest other organisms
Herbivore - plant eaters
Carnivores – meat eaters
Omnivore – eats both plant and meat
Digestion – involves both mechanical and chemical breakdown of food so it can be
absorbed. (Polymers > Monomers utilizing hydrolysis.)
Gastro vascular Cavity (GVC) – digestive sacs with a single opening
Alimentary Canals – Humans; digestive tubes that run between two openings, the mouth
and the anus.
Peristalsis – rhythmic wave-like motion (of smooth muscle) to move food down the
esophagus
Chapter 41
Nutrition
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Mouth – Mechanical digestion begins with the mastication of the food. Chemical digestion of starches begin via secretion of Amylase
Pharynx – The epiglottis opens when we swallow
Esophagus – Peristalsis squeezes the bolus down to the stomach
Stomach – Chemical digestion of protein, gastric juices in the stomach contain
1. Enzymes that act on protein (pepsin)
2. Hcl (pH of 3)
The mucous lining of the stomach protects the organ CHYME which is the mixture of food and gastric juices together
Small Intestine – Here chemical digestion acts on carbohydrates, proteins, fats, and nucleic acids. The Duodenum produces enzymes that in
addition to hydrolysis provide for the chemical digestion.
1. Blood vessels - circulate around the cross section of the small intestines.
2. Villi – their function is to increase the surface area for absorption of more nutrients.
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Carbohydrates – maltase, sucrace, and lactase
Lipids – Lipase
Proteins – Proteinase
Nucleic acids – nuclease
A gastro vascular cavity is possessed by worms and hydras
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Buffers – Take care of the acidity in the small intestine so that the enzymes can work properly. The acidity of the chyme in neutralized by
HCO3 – (bicarbonate)
H + HCO3-  H2CO3  H20 + CO2
(Bicarbonate) (Carbonic acid)
Chapter 41
Nutrition
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Pancreas – secretes HCO3- and pancreatic enzymes (similar to those of the small intestine lipase).
Produces hormones like insulin. By adding the bicarbonate, the pH is lowered from an acid
environment to neutral, allowing the enzymes in the digestive system to breakdown food.
Bile – a substance that helps stabilize fat and water emulsion (helps to breakdown fat) Alkalinity is
from 7 – 8. The bile is stored in the Gall Bladder and made by the liver.
Large intestines – Function is to absorb water and vitamins
Humans cannot digest cellulose. Cows can digest cellulose because they contain Rumen (multisegmented stomach). Rumen is a symbolic bacterium that makes enzymes that digest cellulose.
BMR – (Basal Metabolic Rate). This is the amount of calories needed to maintain basic body
functions.
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1 gram of carbohydrates = 4 cal
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1 gram of protein = 4 cal
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1 gram of alcohol = 7 cal
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1 gram of fat = 9 cal
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1 Cal = 1 Kcal
1 Cal = 1000 cal
Chapter 38
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Circulatory and Respiratory
Cardiovascular
2 Types:
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Open Circulatory System – circulates hemolymph, no vessels containing the fluid.
2.
Closed Circulatory System – circulates blood. The circulatory system of a
vertebrae consists of: Arteries  Arterioles  Capillaries  Veinuoles  Veins
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Capillaries – the space where gases and nutrients are exchanged There is no RBC
exchange in the capillaries.
* The link between the arteries and veins
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Fish
Amphibians
Birds and Mammals
have a 2-chambered heart, one atria and one ventricle.
have a 3-chambered heart, two atria and one ventricle.
have a 4-chambered heart, two atria and two ventricles.
Chapter 38
Circulatory and Respiratory
Cardiovascular
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Atrium: are thin walled chambers that sit on top of the ventricles.
The atrium always receives blood. The right atrium contains the SA NODE or Sino atrial node. The
node is the pacemaker of the heart. It has conductive tissue that regulates the beat and contraction of
the heart. The brain controls the functions of the sino atrial node.
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Ventricle: are thick walled chambers that are underneath the atria. The left ventricle is thicker than
the right (so that has the strength to move blood throughout the entire body).
Ventricles always pump blood away from the heart.
The left ventricle pumps blood to the rest of the body other than the lungs, this is called systemic
circulation. In systemic circulation the arteries contain highly oxygenated blood, and the veins
contain low oxygenated blood.
The right ventricle pumps blood to the lungs, this is called pulmonary circulation. In pulmonary
circulation the veins carry the highly oxygenated blood and the arteries carry low oxygenated blood.
Rules
1) Ventricles always pump blood away from the heart
2) Atria always receive the blood
3) Since the atrium receives blood, the veins always bring blood to the heart.
4) Arteries always take blood away from the heart.
5) Veins always connect to atria.
6) Arteries always connect to the ventricles.
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Chapter 38
Circulatory and Respiratory
Cardiovascular
• Systole - The measure of the contraction of
the left ventricle and of the pressure exerted
on the arteries and veins (about 120).
• Diastole - The measure of the relaxation of
the left ventricle (about 80). A high diastole
(94 and above). Can lead to an aneurism,
stroke or a heart attack.
Chapter 38
Circulatory and Respiratory
Cardiovascular
Connections of arteries and veins
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Pulmonary Artery connects to the right ventricle. It pumps the blood to the lungs. Blood
leaving the right ventricle has the lowest ph (least amount of oxygen saturation).
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Aorta connects to the left ventricle making it the biggest artery in the body. The aorta
pumps blood to the rest on the body.
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Superior Vena Cava, Inferior Vena Cava and opening of the Coronary Sinuses all attach
to the right atrium. They bring blood from the rest of the body excluding the lungs to the
right atrium. The blood is deoxygenated (without oxygen).
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Pulmonary Veins bring highly oxygenated blood from the lungs to the left atrium. Not
all veins contain low oxygenated blood, and not all arteries contain highly oxygenated
blood.
Chapter 38
Circulatory and Respiratory
Cardiovascular
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Valves: are either located at the entrance or exit of ventricles.
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Atrioventricular valves are located at the entrance of ventricles.
a.
Tricuspid - located at the entrance of the right ventricle.
b.
Bicuspid or Mitral – located at the entrance of the left ventricle.
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Semilunar valves are located at the exit of ventricles.
a.
Pulmonary Semilunar – located at exit of right ventricle.
b. Aortic Semilunar – located at exit of left ventricle.
Veins have valves and arteries don’t because the muscles of the arteries are
stronger so they don’t need valves.
Chapter 38
Circulatory and Respiratory
Cardiovascular
Blood:
• Plasma – blood cells; Erythrocytes, Leukocytes, and Platelets
• Plasma makes up 55% of the volume in blood, 90% of that is water composition
• The proteins Fibrin and Fibrinogen are the clotting factors of blood.
• Plasma contains imuno globulins (antibodies), fat, minerals, electrolytes, proteins,
and nucleic acids.
• Serum – plasma minus its clotting factors (no fibrin or fibrinogen)
Gas Exchange:
• Carbon dioxide (CO2) is carried in the from of bicarbonate (HCO3)
• Air sacs (alveoli) reverse the Bicarbonate and exhale
• Sensors detect: pH, O2, and CO2 to regulate the respiratory system.
• Fishes have gills, insects have a tracheal system, and Vertebrates have lungs.
Chapter 43
Immune System
1. Non-Specific Defenses
Help prevent entrance and spread of microorganisms into the body.
Skin and mucous membranes, also some defensive WBC, inflammatory response, and anti-microbial proteins.
a.
Skin and Mucous Membrane
Barrier against entrance of certain organisms.
Sweat glands help destroy
1.
pH of 3 to 5 discourages organisms form growing
2. The substance Lysozyme – Chemical secretions that disrupt the cell wall of bacteria.
3. Through tear ducts (tears)
4.
Found in saliva and sweat
5.
Forms anti-microbial agent
6. Attacks bacteria cell walls that destroys wall and cell leaks. Penicillin acts in this way.
b.
Stomach and G.I. Tract
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Acidity (pH of 1 to 3) destroys bacteria, but doesn’t always destroy what they produce which is toxins. Toxins are
usually what make you sick when infected.
c.
Respiratory
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Hairs, etc. used to trap dirt, organisms, particles in mucous
d.
Phagocytes and Natural Killer Cells
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Wondering WBC- travels through the use of the bloodstream but then leaves blood through diapedesis (moving
through tissues at junctions between cells) to go to location of trouble/ infection.
1. They get bigger and are now called macrophages or big eaters.
2.
Neutrophils- become phagocytic in infected tissues (first response)
Chapter 43
Immune System
Natural Killer Cells
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Will destroy your own cells once they have been infected with pathogen to keep the bacteria from multiplying.
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Attack cell membrane but doesn’t digest whole cell
a.
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Inflammatory Response
Inflammation is a response to injury or microbial response.
Swelling, rise in number of white blood cells, increase in heat (more blood to the region)
Chemical release – histamine which triggers the immune response
First to the scene is the Neutrophils
Second to the scene is the monocytes (which develop into macrophages)
Pus is created when live and dead white blood cells and pathogens are left during and after the immune response
a.
Injured cell emit substances that trigger the inflammatory response
b. Substances near the site of infection: histamine (alarm substance)
c.
Small blood vessels dilate and become leakier, causing redness and swelling
d. Migration of phagocytic WBC is enhanced
Neutrophils arrive first, followed by monocytes, macrophages.
e.
Increased activity of phagocytes
f.
Also end up with clotting proteins that begin to seal off injury site
g.
Stimulation of WBC release from bone marrow
Anti –microbial Proteins
1. Interferon: a substance produced by virus-infected cells to help other cells to resist the virus. They are host specific, and not virus
specific.
2. Compliment: proteins (20 different kinds) made by body – not the same as anti-bodies
i.
Some will coat invading microbes to facilitate phagocytosis (circulating in the blood stream) this process is called Opsonization.
ii.
Another function amplifies inflammatory response by stimulating histamine release and attracting phagocytes.
Chapter 43
Immune System
Specific Defenses of the Host
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Antigen
Any substance capable of generating an immune response in your body
Any substance grater than 10,000 Dalton molecular weight
Any bacteria can have 100 antigenic determinants (sites on an antigen that can elicit response)
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Vaccination
Injecting dead or live organisms into body to produce response (to develop anti- bodies) to build immunity
Kill or attenuate (weaken) antigens
Body recognizes as not part of self and produces antibodies.
Either quick acting or memory cells.
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Immunity
1. Active: your body makes the antibodies yourself when exposed to antigen.
Naturally: you catch antigen
Artificially: vaccinate with antigen
2. Passive: you are given the pre-made antibodies (you can’t afford to wait to make them later)
Example: antibodies form mother to fetus through breast milk and genetics.
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Duality of Immune System
Humoral immunity
Production of antibodies (ab)
Defends against free (circulating in plasma) bacteria and viruses
B cells are responsible
Chapter 43
Immune System
Cellular based immunity
Humoral based immunity
Thymus (beneath breastbone)
Bone Marrow
T- Cell
B- Cell
Memory cells
Effecto
r cells
Memory
cells
Effector cells
1.Killer cell
or cytotoxic cells
(eats effector
cells)
2.Helper T-cells
(communicators)
3.Suppresor cell
(checks/
balances)
(keeps killer
cells under
control)
Effector cells
Plasma cell
(makes antibodies)
which stay in
plasma.
Memory cells
Effecto
r cells
Memory
cells
Chapter 43
Immune System
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Cell-mediated immunity
Protect against bacteria and viruses that have already infected cells.
Phagocytosis takes place
T cells are responsible
Lymphocytes
Come from: stem cell in bone marrow differentiates into lymphocytes (and all other blood cells).
T-cells
Phagocytosis
Left and went to thymus and spleen
B-cells
Produce antibodies
Mature in the bone marrow
B-cells
Effector cells
Do the fighting
Called plasma cells
Are able to produce as many as 2000 antibody MC’s per second
Life expectancy is 4 to 5 days
Memory cells
Remember known pathogens for the next time the body is infected (they will be more efficient in making more
effector cells).
Chapter 43
Immune System
T-cells
Effector cells
3 Types
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Helper T-cells
Stimulates the making of phagocytes
Helps both B and T cells with communications between all cells
AIDS virus lacks these cells, so they can’t make T and B cells (minimal)
Cytotoxic T-cells
These phagocyte cells are made
Eat effector cells
Suppressor T-cells
Slows down both helper and cytotoxic cells from growing out of control
Are used mainly at the end of infection/ virus killing process
Memory cells
Stores the history and physiology of the virus in case the body encounters it again
Chapter 43
Immune System
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Primary Response (when first encountering pathogen)
Begins the process to build enough resistance to fight pathogen
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Secondary Response (when encountering pathogen again)
Can act more quickly this time because memory of the pathogen encountered has been saved in the
memory cells and the body can quickly make many anti-bodies to fight it
Immunoglobulins (IG’s) (antibodies)
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IgM
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IgD
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Almost always bound to plasma membrane of B-cells
IgG
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Largest and produced first during early response
Most numerous out of all antibodies
Can cross placentra
IgE
Responsible for allergic responses to pathogens
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IgA
Antibodies that secrete, also found in milky secretions (coloestrom), tears, etc.
Chapter 43
Immune System
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Disorders of the Immune System
Auto Immune disease (Lupas Erythromatous)
White blood cells don’t recognize body cells (after changing) and eat/ attack them
AIDS –Acquired Immunodeficiency virus
Caused by the human Immunodeficiency virus
SCID – severe combined Immunodeficiency
ARC – AIDS related complex (happens before AIDS)
Night sweats
Fever
Weight loss
Stress
Killer cells
Allergic Hypersensity – allergic reactions
Chapter 44
Organ Systems
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Osmoregulation - controlling the solute balance and the gain and/or loss of water.
Flame cells- (protonephridia) regulates the entrance and exit of fluid. Ex. Flat
worms.
Metanephridia – also function as excretory cells or structures. Found in annelids
(earthworms.)
Malpignian tubes- their function is in the excretion and Osmoregulation. Found in
arthropods (insects.)
Kidneys- regulates body fluids in vertebrates by removing nitrogenous wastes and
functioning in Osmoregulation by adjusting the concentrations of various salts in the
blood stream (filtration and re-absorption).
Nephrons- the basic functional units of the kidneys. 180 liters of fluid are passed
through the Nephrons in a single day, but only 1.5 liters are excreted as a waste product,
the rest is absorbed by the cells.
Chapter 44
Organ Systems
Renal
Arteries
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(Bring
blood and
nutrients
to…

Kidneys

Filtering
out liquid
waste
Renal Veins

Return
filtered
blood
throughout
the body
Chapter 44
Organ Systems
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Components of the Kidney:
Cortex
Medulla
Renal Pyramids
Renal Pelvis
Ureter
Parts of the Nephron:
Glomerlus- Site where filtration
occurs. A network of capillaries
covered by the Bowman’s Capsule.
Proximal Convoluted
Tubule
Loop of Henley
Distal Convoluted
Tubule
Collecting Duct
(Common duct in for
many nephronsurine.)
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Function in absorption and
filtration, back into the
circulatory system.
Chapter 44
Body Systems
General Physiology of Nephrons
1.
Filtration
2.
Secretion, or excretion of waste that is made in the liver.
3.
Re-absorption
4. Water Retention (in simple cuboidal epithelium.)
5.
Regulation of Salt- ionic balance in the blood
6.
Regulation of volume of blood
3 Forms of Nitrogen Waste
1. Ammonia – produced by aquatic animals
2.
Urea- mammals and adult amphibians
3.
Uric Acid- snails, insects birds, and some retiles
Nephrons anatomy functions:
-Secretion site-proximal and distal convoluted tubules. Example- control over the secretion of hydrogen ions
- Reabsorption of NaCl: Proximal Convoluted tubule, and the Loop of Henley (including the ascending loop of Henley)
- Regulation of K+ (potassium) – Occurs at the distal convoluted tubule.
- Reabsorption of H20 – proximal Convoluted Tubule, descending limb of the Loop of Henley, Distal Convoluted Tubule,
and the Collecting duct
- Reabsorption of Glucose- Proximal Convoluted Tubule
Chapter 44
Body Systems
•
•
•
•
•
•
•
•
•
•
•
Regulation of Body Temperature (thermoregulation)
External (Environmental factors)
1. Conduction – direct transfer of heat between the environment and an organism. Ex- when an
animal sits/lays on a hot rock to warm itself.
2. Convection- a current that flows by you. Ex – the wind chill factor compounds the harshness of
winter temps.
3. Radiation- the transfer of heat between the environment and an organism with no contact. Exrays of the sun
4. Evaporation- when a liquid is removed from a surface leaving it at a cooler temperature. Exsweat – evaporates- lowers temp
-Ectoderms - Body temperature regulation by external factors. Ex- cold-blooded animals/organisms
-Endoderm’s- body temperature regulation by metabolism; both ectoderms and endoderm’s- use
environmental factors for regulation of temperature. Ex- humans
-Hypothalamus- structure in brain responsible for thermal regulation and other functions.
-Ruffini Organs- warm temperature sensors in the skin
-Bulb OF Kraus- cold temp sensors in the skin. Ruffini organs and Bulb of Kraus send messages
through the nerves brain hypothalamus regulation of body temp. By burning glucose, shivering
is an immediate breakdown of ATPquick heat.
Fish have a counter current mechanism veins and arteries run close togetherexchanging
heat (arteries radiate heat to veins)
Chapter 45
Hormones
2.
Hormones
3 key components
1. Made by endocrine system
Target cell that receive information as needed
3. Circulated by the blood stream
Endocrine System
-Endocrine glands
-No ducts
-Secretions called hormones
Exocrine System
-Exocrine glands
-Have ducts
-Secretions called substances. Example- sweat, mucous, and digestive
enzymes
•
•
•
•
•
•
Endocrinology- the study of hormones and actions
3 main classes of hormones
1. Steroid (fats)
Sex hormones
2. Amino acid derivative
Epinephrine
3. Peptides
•
•
b. Pheromones
Not hormone; chemical agents that function in attraction
between animals of the same species.
•
•
•
c. Local Regulators
-Example: neurotransmitters.
-Example: acetyl choline.
•
d. Growth Factors
•
•
E. Prosaglandian
Modify fatty acids found between cells, cause
retraction
Chapter 45
Hormones
Only the hormones are Endocrine
- Example: Pancrease- endocrine
and exocrine
-HCO3 – exocrine
-Enzymes-exocrine
-Insulin- endocrine (glucose to
glycogen)
-Glucagon- (glycogen to glucose)
Ecdysame-responsible for molting
and metamorphosis in animals
Acetyl (enzyme) Cholin


Acetylcholine


Acetyl (enzyme) Cholin
Chapter 46
Reproduction
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Asexual Reproduction-cloning
1. Budding
-Yeast cells
2. Fragmentation – each segment can re-constitute the whole organism
-Some fungi
3. Release of specialized cells
-Sponges
4. Regeneration- removing a part of an organism- the organism reconstitutes/regrows part that was lost
5. Parthenogenesis – no sex involved, no sperm (asexual)
- End in haploid
b. Sexual Reproduction – meiosis
1. Spermatogenesis – production of sperm
2. Oogenesis – production of eggs
Fusion of 2 gametes (sperm and egg)
Fertilization
Zygote
c. Hermaphroditism- one organism with both sexes, example: opithorchis clonorsis sinensis
•
d. Sequential Hermaphroditism- starts out as one sex then changes sex when reaches adulthood, example: African frogs
•
1.
2.
Fertilization
External – egg fertilized outside of organism
Internal – egg fertilized in organism
•
•
Reproductive System
Most organisms have separate sexes
Chapter 46
Reproduction
•
•
•
•
•
•
•
•
•
•
•
•
•
Male Reproductive Organs
Testis- sperm is produced outside body cavity – must be cooler temperature
Epididymus- site for 2nd phase of sperm transfer
Sperm cells mature and are stored here
Vas Deferens- muscular in nature, sperm travels is spermatic duct
Semi vesicle – secretes a thick clear fluid
-Contains mucous and amino acids (food for sperm)
- Produces 60% of semen (protein, sperm)
Prostate – raise pH (more basic to less acidic) sperm cannot survive in acidic
environment
-Eliminates acidity from female vagina
Bulbouretheral gland – lubrication
Urethra
Penis
Semiephorous tubules- make sperm- tiny tubes within the testis
Chapter 46
Reproduction
•
•
•
•
•
•
•
•
•
•
•
•
Female Reproductive Organs
Uterus- implementation of embryo
-Endometrium- lining
Vagina
Cervix-opening of uterus
Clitoris-erectile- female equivalent to penis
Labia majora-protects
Labia minora erectile
Ovary- produces egg
Oviduct- fallopian tube
-Fertilization takes place. Swims
Uterine contractions move sperm
Mammary glands- alveoli made of epithelial tissue
•
•
•
•
Pregnancy
Starts at fertilization
Conception
Includes gestation
Chapter 46
Reproduction
Female
Meiosis 1 (at birth)
Meiosis 2 (after
fertilization)
-
Male
2N

N
N
 
N N N N
Oogenesis
- Before birth
- 1st cell
- Meiosis 1
Meiosis 2 doesn’t take place till after
fertilization
- 1 viable egg. 3 polar bodies
Meiosis 1 (from
birth to puberty)
Meiosis 2 (all are
different)
-
2N

N ≠ N
 
N≠N≠N≠ N
Spermatogenesis
- Meiosis 1 and 2
- Every cell
- 4 sperm
Happens continuously after puberty
Chapter 46
Reproduction
Zygote
• Fertilized egg
• Cleavage begins
• 1.
Blastula
• 2.
Morula (16-64 cells)
• 3.
Gastula
• 4.
Organogenesis (organ creation)
Hormone
• Placentally made
• HCG (human chorionic gonadtropin) (when fertilization occurs, this is
produced)
• Produced after formation of a placenta.
• Excreted in urine (pregnancy test)
Chapter 46
Reproduction
Pregnancy
Trimesters:
1st 3 months
-Organogenesis
2nd 3 months
-Rapid growth
-Active fetus
3rd 3 months
-Extremely rapid growth
-Lower activity
-Parturation (birth) begins
Chapter 46
Reproduction
Conception
• 3 major
• Rhythm method (counting days)
• Prevention of zygote implementation –IUD
• Physical barriers- condoms, diaphragm
• Chemical contraception- Norplant, birth control pill, abortion pill.
• Withdrawal
Reproductive Technology
• Ultrasound
• Amniocentesis (extracting ovarian fluid)
• Chorionic villi sampling
• Invitro-fertilization (test tube babies)
Chapter 47
Reproduction
•
•
•
•
•
•
•
•
•
•
•
Embryology
Fertilization- union of sperm with egg. Fusion of sperm nucleus and egg nucleus
Acrosomal reaction
Digestive enzymes work to allow sperm nucleus into egg
Cleavage – takes place after fertilization (divisions occurring in a cell into something bigger)
Morula- late cleavage (round ball)
Blastula- blastocyst (hollow ball)(implantation)
Gastrula- invagination of blastula leads to formation of gastrula.
The archenterons is formed
Result in formation of digestive tract
In chordates a layer buds off from archenterons to give rise to primary germ layers
Primary germs layers
•
Endoderm
•
Mesoderm
•
Ectoderm
Chapter 47
Reproduction
•
•
•
•
•
•
•
•
•
•
•
Organogenesis (chordates) – specialized organ systems
Dorsal mesoderm forms notochord
Ectoderms form neural tube (will be CNS) central nervous system, epidermis, inner ear,
and lens of eye.
Mesoderm forms coelem lining, muscles, skeleton, gonads, kidneys, and most of
circulation system
Endoderm forms digestive tract lining, liver, pancreas, and lungs
Metablastic Cleavage –not all cells undergo cleavage
Yolk rich eggs
Hollowblastic Cleavage- all cells with eggs undergo cleavage
Humans
Chapter 48
Nervous System
•
Nervous System
Pons- reflex and relay
•
•
•
•
•
•
Medulla- center:
Respiratory
Cardiac
Vasomotor
•
Hypothalamus- deeper uncontrollable things
•
Corpus Callosum- connects hemispheres
Thalamus- switchboard
Nervous System
•
Neuron- functional (basic) unit of the nervous
system
•
•
•
•
•
Impulse
Dendrite
Cell body
Axon
Synapse- communication between a neuron
and another neuron on a muscle fiber or a
gland
Another neuron, muscle cell, endocrine
gland.
•
Chapter 48
Nervous System
•
•
•
o
•
•
o
o
o
o
Electrochemical Impulse
Dendrites to the axon
Neurotransmitter
Example: acetylcholine
Neurotransmitter
Acetylcholine
Acetyl group + choline group
Make and break by enzyme action
When neurotransmitter is released, the
permeability of the cell membrane is
changed.
Flushing of Na+ and K+ ions.
+ 
to contract
+++++++++++++
Inside cell
++++++++++
----------------Inside cell
•
•
•
-This causes the muscle
- Resting cell
Kurari plant
Anesthetic
-enzyme can’t work
(don’t allow acetyl and choline to combine)
Nerve gas
Chapter 48
Nervous System
- Works on the same principle. Don’t
allow acetylcholine to be broken down.
Tetanus
Botulism
Central Nervous System (CNS)
Includes brain and spinal cord
Peripheral Nervous System (PNS)
12 pairs
31 pairs
Olfactory
Optic
Ocular motor
Trochlear
Trigeninal
Accessory
Facial
Vestibulocochlear
Glossopharangyl
Vagus
Accessory
Hypoglosseal
Cervical-7
Thoracic-12
Lumbar
Sacral
Spinal cord ends at L2
(Allows for spinal tap at L3 and L4)
Chapter 48
Nervous System
Functions of Nerves (PNS)
•
o
o
•
o
•
•
Automatic
Unconscious activity-involuntary, autonomic activity.
Autonomic Nervous System (ANS)
Sympathetic (fight or flight)
Increased heart rate increased respiratory, increased blood pressure, adrenaline, ECT.
Parasympathetic (conservative)
Inhibits sympathetic nervous system, also active in digestive process and sleep.
•
o
Somatic- capable of innervating
Unconscious activity, voluntary
o
o
•
•
•
Supporting cells (in addition to neurons)
Do not get replenished
Neuroglia (glial cells) for support and protection. Capable of reproduction.
1. Oligodendrocytes- help insulate (fatty) (protection)
2. Astrocytes- feeder cells (link between neuron and blood)
3. Microglia- specialized WBC (macrophage only in CNS)
Chapter 48
Nervous System
Brain
Cerebral Cortex (hemispheres)
-4 lobes:
• -Frontal
• -Parietal
-Occipital
-Temporal
Muscular dystrophy- myelin disorder
Corpus Callosum
• Bridge between 2 cerebral hemispheres (allows exchange of information)
Chapter 48
Nervous System
Thalamus
•
Switchboard- directs the impulse to the
appropriate place.
Hypothalamus
•
Homeostasis, emotions, ANS (autonomic
nervous system) (non-voluntary actions).
Medulla Oblongata
•
Respiratory center, cardiac center, vaso-motor
center.
PONS
•
Reflexes and switchboard function.
Spinal Chord
•
Reflexes and a pathway for motor and
sensory impulse.
Neurons
•
Sensory
•
-Perceive and take to brain.
•
-Receptor to brain.
•
Motor
•
-Message that brain sends.
•
-Brain to muscle or gland.
Chapter 49
Plants
•
•
Page 1015- muscles microscopic structures
Sarcomere- functional unit of muscle
•
•
•
From z line to z line- ½ I band + ½ other I band.
The middle of I band
What contributes to muscle striation (light
microscope)
•
•
•
•
I band= actin
A band= actin
H band= middle of A band
- No actin (only myosin)
•
Z lines get closer during contraction.
•
Heterosporous- having megaspores which develop
into gametophytes bearing archegonia (female), and
microspores which develop into
3) Sphenophyta
•
Are homospores
•
Have a photosynthetic free living gametophyte
•
Sporophyte is dominant
•
Have flagellated sperm ex- epuisetum
4) Pterophyta (ferns)
•
No seeds
•
Have megaphylls= equivalent of leaves
•
Most have compound fronds
•
Have sporophylls & their fronds
•
Have structures call Sori- rust like structures
on the fronds.
•
Have flagellated sperm- must have water to
spread/ fertilize
•
Spores develop into prothalium or
gametophyte
•
•
•
•
•

•
•
•
Terrestrial Adaptations of seeded/ vascular plants
1.
Gametophyte is reduced
2.
Pollination evolved
No flagellated sperm
3.
Evolution of seed

Seed- zygote that develops into embryo that is
packed with food supply with in a coat.
4.
Seeds replaced spores- as means of dispersion
5.
Spores if still present are produced by
gametophyte (makes spores)
6.
Majority of seed plants are dicot
Chapter 49
Plants
Monocot
All monocots have
paralleled venations
Leaf wraps around
stem
Fibrous root system
Flower multiples of
3
Xylem/ phloem are
arranged in bundles inside
the stem
Xylem/ phloem are
arranged in a circle inside
the root
Dicot
All dicots have
netted venations
Leafs are attached to
stem by a petiole
Tap root
Flower multiples of
4 and 5
Xylem/ phloem
bundles are arranged in a
circle inside the stem
Xylem/ phloem are
arranged in a X shape
inside the root
Chapter 49
Plants
Gymnosperms
Produce naked seeds
Evolved production of pollen
Divisions of:
•
1. Cycadophyta
•
2. Ginkophyta
•
3. Gnetophyta
•
4. Coniferophyta (pines, furs, redwoods)
•
1.
2.
•
3.
4.
5.
6.
Structures that belong to the Gymnosperms:
Fibers- for support
Tracheids- function in eater transport and support
Are made of Xylem tissues
Are heterosporous
Sometimes it takes 3 years to produce mature seeds
Have winged seeds
Conifers are the tallest, largest, and oldest living organisms today
Chapter 49
Plants
Angiosperms (Flowering plants)
1. Covered seeds- main characteristic
2. Divisions:
• Monocot
• Dicot
3. Vascular tissue are more refined
(detailed)
4. Contain vessel elements that evolved
from Tracheids
5. Xylem is reinforced by fiber
6. Double fertilization- only applies to
angiosperms
Life cycle of Angiosperms
• 1.
Involves double fertilization
• 2.
Haploid spore Megaspore
• Microspore give rise to
gametophyte which is retained within
the sporophyte
• Pollen grain- (male part) have 2
haploid nuclei
• Ovules (female part) have 7
haploid nuclei, with one large central
cell with a 2N (diploid) nuclei
•
• 65 million years ago during the
crustaceous period the angiosperm
became dominant, and are still
dominant today.
Chapter 49
Plants
Flower Anatomy
•
Contain reproductive structures
•
Made of whorls of modified leaves
•
•
1. Sepals – sterile structures, not involved
in fertilization or pollination, the enclosed
bud
•
2. Petals – sterile structures, but aid in
attraction of pollinators
•
3. Stamen – produce pollen
•
Anther- produces pollen
•
Filament- holds the anther
•
4. Carpal – seed bearing structure
•
Stigma
•
Style
•
Ovary
Fruit
A ripened ovary that protects dormant seeds
and aids in dispersal
3 Kinds
•
1. Aggregate- several ovaries on the same
flower
•
Raspberries
•
2. Multiple Fruit- developed from several
flowers several (ovaries)
•
Pineapple
•
3. Simple fruit
•
Apple, cherry, orange
•
•
•
•
•
•
Seed Plants (angiosperms)
Heterosporous
No flagellated sperm
Wind or insect disseminated
Monocot/ dicot
Double fertilization
Chapter 49
Plants
Root
•



•
•
Function:

Absorb H20, nutrients, and minerals

Anchor

Store food
2 Types:
1. Tap root – (found in dicots) large root that is
vertical with many secondary roots.
2. Fibrous root- (found in monocots) mat of thread
like root system. Roots hairs greatly increase
absorption of water (increasing surface area)
•

Stem

The piping of a plant
•
•
Modifications
1. Stolen- horizontal stems that run along the
surface of the ground
Strawberries, spider plant
2. Rhizomes- horizontal stems that run
underground
Iris, Kentucky bluegrass
3. Bulbs- vertical underground stem with leaves
o
•
o
•
•
•
•
Leaves
1. Main function- photosynthesis
2. Petiole that attaches the leaf. Is absent
in monocot
•

Classification of leaves and arrangements
Some leaves have modifications
•
•
•
•
1.
2.
3.
4.
•


Cell growth in plants
Growth by the addition of cells
Growth is irreversible a increase in cell size
mostly cue to uptake of water by vacuoles
Tendrils- for clinging and support
Spines – for defense (cactus)
Succulent- store water
Colorful- attract pollinators
Chapter 49
Plants
Types of plant cells
•
1. Parenchyma- loosely packed thin walls,
photosynthetic (contains chloroplasts)

Contain photosynthetic cells, usually in the
leaves

Function in storage and support
•
2. Collenchyma- non-uniformly thick
walled

Function mainly in support and storage
•
3. Sclerenchyma- thick walls

Have fiber cells called sclerids
• o
Lignin gives hardness, an example is a
almond or a walnut
•
May be dead at maturity
•


•

•
•
•
4. Xylem- lacks nucleus and ribosome’s at
maturity- fiber cells, water transport
Trachids- long, this tapered tubes with lignin
(not living) function in support and water
transport through pits
Vessed Elements- wider, shorter and less
tapered
5. Phloem- functional at maturity (living)
Lack nucleus and ribosome’s
Consist of:
1. Sieve tube members and sieve tube
plates
2. Companion cells- contain nucleus and
ribosome’s, function to serve and aid
Chapter 49
Plants
•

Apical meristem- undifferentiated tissue
Located at the tip of roots and in bud shoots. The apical meristem supplies cells for the root and
shoot to grow in length.
•
Endodermis

Single cell thick, innermost layer of cortex, forms layer between cortex and Steele.
•
Pericycle

Just inside endodermis

Layer of cells that may become meristematic to form new tissues of lateral root or secondary root.
•
Wood

Secondary xylem
Bark

Any tissue outside the vascular cambium- the actual living tissue of the plant
Vascular cambium or precambium

Meristematic tissue – differentiate new tissue- deposits new phloem
Mesophil

(Parenchyma) for photosynthesis
•
Primary Meristem- protoderm, ground meristem, procambium
•
Primary xylem and phloem develop form procambium or vascular cambium
Chapter 49
Plants
Bryophytes
(Bryophyte)
(Mosses)
Seedless vascular
(Sporophyte)
(Lycophyta)
(Sphenophyta)
(Pterophyta)
Gymnosperms
(Conifers)
Seeds
Seedless
Non- vascular
Angiosperms
(Flowering Plants)
Vascular Tissue
Chapter 36
Plants
Transpiration and relocation of substances in plants
–
•
•
•
•
•
•
1.
2.
3.
4.
5.
6.
–
Water and minerals enter the plant at the root level
Through the root epidermis
To the cortex
To the endodermis
To the Steele
To the xylem
Finally ascending upward to leaves
There is a proton pump inside the tissue responsible for facilitating conduction
2 ways water and minerals enter the Xylem
•
1. Via the simplest – the living continuum of a cell
•
2. Via the apoplast- the non living matrix of a plant
–
At the endodermis level, the apoplastic route is blocked by a casparian, part of the endodermis
Reasons for Casparin Strip
•
1. To ensure that certain substances are selected
•
2. To prevent leaking
Chapter 36
Plants
Ascent of Xylem Sap
• 1.
Happens by transpiration or the loss of water, powered by solar energy.
Transpiration works from the root (sink) to the leaves (source)
•
In order for transpiration to occur the following is required:
•
Adhesion of water to cellulose
•
Cohesion of water
•
Evaporation of water
•
Transpiration through xylem
•
Adhesion of water to xylem
•
•
2.
Due to root pressure- root pressure drives water up by ions and leads to Guttationleakage of water on leaves, like dew.
Dead cells (xylem) have a lower water potential than the soil, meaning xylem is
hypertonic to soil, osmosis will occur naturally, driven to leaf by transpiration.
Chapter 36
Plants
Guard Cells- found around stomata opening
 
Regulate the opening and closure of stomata
 
Allow for gas and water exchange
 
If stomata are closed there is a decrease in photosynthesis causing
photorespiration to begin.
 
When guard cells accumulate K+ ions (potassium) and their turgor
pressure increases- stomata open
 
Water and electrolyte movement control the opening and closing of the
stomata
 
Potassium drives water in and out of the cell
 
When potassium is inside the central vacuole of the guard cells, water
will follow it allowing the stomata to shrink in size. This gives room for guard
cells to expand, making the opening bigger.
Chapter 36
Plants
Plant Types
•
1. Xerophytes- plants in hot regions
•
Adaptations of xerophytes
•
Stomata are found on the underside of their leafs and are recessed (the openings grow deep
within the leaf)
•
Have thick leaves
•
They store water in stems or leaves
•
During the summer they loose leaves to minimize water loss
•
C4 plants- 4 carbon organic substances store CO2 during the night so they can maintain
photosynthesis during the day. The stomata have to close during the day to keep from loosing water
through transpiration
•
CAM plants- uses an organic substance other than the 4c to store CO2. Example – yucca
•
•
2. Mesophites- found in plants in a medium climate
Stomata found on top and bottom of leaves
•
•
3. Hydrophites- found near water
Stomata is found on the top of the leaves
Chapter 36
Plants
Absorption of Food
•
Food and sugars are made in the leaf (source) and moved to the (sink) root.
•
Translocation- movement of substances from source to sink (downward)
•
•
•
•
•
More than 90% of water loss is due to transpiration via the stomata
The Bulk of the dry weight of a plant is CO2
95-96% of the dry weight of a plant is carbohydrates
4-5% of the dry weight of a plant is minerals
A herbaceous plant contains 85% water
Essential Nutrients of plants
•
Macronutrients- elements required in large quantities
•
Micronutrients- elements required in small quantities
Chapter 37
Plants
Symptoms of mineral deficiency
• 1.
Depends upon the form that the mineral plays.
• 2.
Mobility of nutrients
 
Older leaves usually if nutrient is mobile, the deficiency can also affect
younger leaves in case of immobility.
• 3.
Fertilizer
 
Most fertilizers come with: 20-5-10, referring to the potency of
Nitrogen- Phosphorous- Potassium.
 
Concentration depends upon the plant chlorosis (deficiency of nitrogen)
 
Chlorosis is spotted by yellowing of the leaf (not to be confused with
lack of water)
Chapter 37
Plants
Soil Texture and composition
•
•
•
•
Clay
•
Soil- weathering of rocks
Topsoil- mixture of sand, silt and clay; very fertile soil
Humus soil- contains all the decomposing organic substances
Humus and loamy soil together make the most ideal soil
Consists of negatively charge electrons; therefore it attracts positively charged electrons. This
allows clay to hold on to positively charge ions (potassium, calcium, iron, magnesium) => more
fertile soil
•
Clay prevents leaching of minerals; you want it in the topsoil. Negatively charged ions tend to
leach away from the soil quickly, clay helps keep the positive, and a little of the negative.
Soil Management
•
1. Fertilizers- the best are organic forms, they last longer because they slowly degrade, examplemanure
•
2. Irrigation- most effective: drip irrigation
•
3. Erosion prevention- ground cover, terracing, wind breaks (trees), rotating crops (nitrogen
fixation)
Chapter 37
Plants
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Nitrogen Fixation
N2> NH3 (ammonia) >NH4+, Nitrifying bacteria converts this into NO3 (nitrate)
Nitrogenase reduces nitrate to form NH3
Nitrogen fixing plant (N03-) is called Legumes, which includes beans, peas, ECT.
Nitrogen is essential = macronutrient
Found on growth nodule at roots
Rhizobium is an example of nitrogen fixing bacteria
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Nutritional Adaptations of plants
Mycorrhizae- mutual association between plants and fungus
Associated at the root level
Increase the surface area allowing for more water and nutrients
Chapter 37
Plants
Carnivorous Plants
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Ex. Venus fly plant
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Plants that directly ingest organic substances
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Direct feeding
Parasitic plants (don’t rely on photosynthesis)
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Ex. Mistletoe, dodder
Chapter 38
Plants
Reproduction in plants
Flower- reproductive structure of plant
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Mass of modified leaves
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1.
2.
3.
4.
Sepals- sterile structures enclosed in the bud
A modification of a leaf
Petals – color portion of a plant
Sterile structure
Attracts pollinators
Stamen – male part
Produces pollen
Reproductive structure. Consists of:
Anther
Filament
Carpels -female part
Seed bearing structures
Reproductive structures Containing:
Stigma
Style
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Ovary
Chapter 38
Plants
Classification of flowers
• 1.
Complete flowers- contains all parts
• 2.
Incomplete flower- missing one part
• 3.
Perfect Flowers- contains stamens and carpel’s
• a.
(Complete flowers are perfect)
• 4.
Imperfect flower- missing either stamen or carpel’s
• a.
(Incomplete flowers isn’t always imperfect)
• 5.
Monoecious flowers – a flower that is perfect (contains both stamen and carpel’s)
• 6.
Dioecious flowers- have either stamen of carpel
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Double Fertilization
Common characteristic of angiosperms life cycles
Summary:
Meiosis> Pollination> Nuclear Fusion (fertilization)> Embryo (2N0) > Formation of
endosperm (3N)
Chapter 38
Plants
Fruit (ripened ovary)
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Protects and disperses the seed
1. Simple – derives from a single ovary
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Ex. Cherries, soybeans
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2. Aggregate – single flower with many ovaries
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Ex. Raspberries, strawberries
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3. Multiple Fruit- more than one flower
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Ex. Pineapple
Requirements for seed germination
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1. Acts of nature
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An example is a fire- high temp is sometimes
needed for seeds to germinate, but not all seeds
require heat.
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2. Imbibition- soaking up water
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Seed must imbibe water in order to germinate –
starting metabolic activity
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3. Gibberallic acid hormone
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After water imbibes then enzymatic reactions
occur
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Has to do with plant elongation
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The plant needs gibberallic acid to break
dormancy of the seed coat
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Aleuron- top layer of endosperm, where chemical
reactions occur
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Asexual Reproduction In Plants
1. Referred to as Monoculture or
Vegetative OR Cloning
2. Asexual reproduction leads to clones
Advantages
1. Predictable characteristics are passed on
allowing for predictable yields and crops.
a. Once you have a favorable organism,
(hybrid reached by sexual reproduction)
clone it to keep the yield.
Disadvantages
No variation > no adaptability in clones
No chance for crossing over
If one disease comes along it can destroy
the entire crop
An example of this is the Irish potato
famine- they were all the same kind of
potato> Disease came and wiped out the
country’s food supple and killed many people
Chapter 38
Plants
Terms Applying to Cloning
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Stock- the host tree, has its own roots
Scion- what is being grafted to the host
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Development of Pollen
Male- anther growing into microsporocyte (2n) leading to meiosis> 4 microspores (n) > mitosis> pollen
grain
Female- megasporocytes (2n) > meiosis > megaspore (n)> mitosis (yields at least 7 cells)> formation of embryo sac
(female gametophyte)
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Micropyle- the little opening through which the pollen tube enters the embryo sac, called antipodal cells- located at
top to the ovary
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Endosperm- found in the seed
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Provides nutrition for the embryo
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Eating an endosperm when you are eating rice, wheat, and corn, ECT.
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The embryo will not develop within the seed until the seed germinates.

The seed is dehydrated, it only has 5- 10% water in it

When the seed first germinates it produces a structure called a radical, which shoots down and becomes the
root.
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Seed also produces the coleophyle, which grows up forming embryonic leaves.
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Chapter 39
Plants
Hormones
Hormone- chemical produced by an organism a sent to another cell (target cell) to
• Control it. (May travel through bloodstream or xylem).
• Phototropism- movement toward the light (like taxis in bacteria)
• Coleotile- bends towards the light, is the initial stem as the seed has germinated (before
• The plant has fully developed. (Leaf like)
• Auxins- substances (hormones) at the tip of the coleotile that is sent down to the plant
through the xylem.
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1. Amount of auxins on the dark side of the coleotile is higher; this usually causes
rapid cell division, forcing it to bend toward the light.
2.
Darwin and his son did the original study
3. The study was also done by F.W. Went, whom decided that the concentration of
auxins on the dark side is higher. (Bending the plant toward stimuli.
4. Went gave the name “auxins”.
Chapter 39
Plants
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Classes of plant Hormones
1. Auxins (IAA- indo Acetic Acid)- hormone
involved in tropism (movement) ex. Phototropismthe movement toward the light.
a.
Stimulate growth of branch roots- the fullness
and branching of the plant.
i. Allowing for apical dominance
b. Stem growth
i. Apical dominance- the apical meristem of a
shoot is a major site of auxin synthesis
ii. Allows the plant to grow taller and not as
wide
iii. Works by acid growth hypothesis~acid
causes the cross-linking of cell walls to break,
allowing stretching or bending of the plant toward
the light.
c. Auxins can also be used as herbicides, 2-4-D is
a weed killer.
i.
Destroys dicots (dandelions) but not
monocots (grasses)
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2. cytokinins
a. Moving through the xylem
b. Stimulates cell division
c. Affects cell differentiation (auxins can
also do this)
d. Effects apical dominance and lateral
budding
e. It inhibits branch roots – which works
opposite from auxins
f.
Inhibits leaf senescence (aging)
i. Reduces aging process
g. Promotes stomata opening
*Most apical dominance is exhibited by
woody dicots
*Herbaceous doesn’t get woody
Chapter 39
Plants
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1. Gibberellins (GA)- has a stronger effect
than auxins
a. Over 70 different types
b. Causes bolting of a plant- rapid growth
i. Important properties of a gibberalin
1. Rapid growth
2. Growth in length
3. Result in normal growth of mutant
dwarf plant
4. Ex. Genetic corn- by adding gibberalin
you can increase the sixe of the corn by ½.
c. Hormone (gibberalin) is release by the
embryo just after Imbibition
i. Help mobilized energy stored in
endosperm
d. Triggers germination
i. Hormones act at the gene level of
target cells- affects genetic code
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2. Absciccic acid (ABA)
a. Help prepare plants for winter by
suspending primary and secondary growth
b. Inhibits cell division in vascular
cambium
c. Induces seed dormancy
d. Stress hormone
i. Causes leaves to close stomata under
environmental stress- reducing transpiration
and loss water
ii. The ratio of ABA to Gibberalins
determines wither the seed will remain
dormant or germinate.
Chapter 39
Plants
Ethylene
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a.
b.
Gas
Triggers senescence
i. Causing aging (ripening quicker by
softening of fruit wall and loss of greenness)
ii. Aging cell produce more ethylene,
causing the ripening of fruit
c. Before a leaf falls, an abscission zone
forms
i. Auxin levels drop, ethylene levels rise
ii. Stimulates rapid division at stem
(petiole) of leaf
iii. Forms a layer (seal) that prevents
anything from entering (diseases)
plants and trees that drop their leaves in the
winter doe so to prevent desiccation
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Florigen
a.
Stimulates flowering- flower
formation (modified leaf)
b.
Produced by leaves
Chapter 39
Plants
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Hormones mode of Action

Altering gene level or genetic expression

Modifying permeability of cell membrane

Stretching cell walls- allows for bending or
growth mechanism to happen
Tropism- the movement of a plant toward a stimulus
1. Phototropism- the movement towards light with
the aid of auxins
2. Gravitotropism- (geotropism)-root always
orients itself down
Root are positive- they grow down with gravity
Stems are negative- they grow against gravity
(upward)
3. Thigmotropism- response to touch
Ex. Venus fly trap (closes up)
4. Turgor movement- fills up with water, large or
plump
Ex. Guard cells close due to lack of potassium
5. Sleep movement- closing of leaves at night
Ex. Legumes
Potassium ions involved
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Photoperiodism- capability of plant to detect
night and day (phytocrome makes this
possible)
1. long day plant- flowers when there is a
lot of day length, needs less night
2. short day plant- flowers when there is
less light, needs a lot of darkness. Ex. Shining
light on a plant at night will inhibit flowering
3. Neutral plant- flowering is not affected
by light or dark periods
Phytochrome- the pigment that absorbs light
and tells the plant how to behave during
phototropism