Transcript review for the biology regents exam

REVIEW FOR THE
BIOLOGY REGENTS
EXAM
EXAM OVERVIEW
PART A – multiple choice (30 points)
• General knowledge questions
PART B – mix of multiple choice and short
answer (25 points)
• Application of knowledge (graphing)
PART C – short answer dealing with application
of knowledge to real world situations (15 points)
PART D – multiple choice and short answer (15
points)
• Pertaining to the four New York State labs
performed during the school year
GUIDELINES
BRING PENS
• All short answers must be in permanent ink
• Answer sheet must now be done in ink
BRING PENCILS
• Graphs may be drawn in pencil
• Essay questions may be bulleted
UNIT I
SCIENCE AND THE LIVING ENVIRONMENT
•
•
•
•
Scientific method
Controlled experiments
Characteristics of a good experiment
Graphing
Vocabulary
• Observation: what is seen or measured
• Inference: a conclusion based on observation or
evidence
• Hypothesis: a prediction based on available
evidence – should state cause and effect
∙ A correct hypothesis can be tested and falsified
(proven incorrect) using an experiment
∙ The easiest way to write a correct hypothesis is to
use an “if…then” statement
• Theory: an explanation of natural events that is
supported by strong evidence
A Controlled Experiment
Compares the results of an experiment between two (or
more) groups
 Experimental group = group being tested or receiving
treatment
 Control group = “normal” group – should be identical
to the experimental group in every way except they will
not be receiving the new treatment
 Placebo = a sugar pill or fake treatment given to the
control group
VARIABLES
• INDEPENDENT VARIABLE:
♦ The variable being tested – the
variable that the experimenter (I)
put into the experiment
♦ The “if” part of the hypothesis
♦ The variable plotted on the X axis
• DEPENDENT VARIABLE:
♦ The data (D) being collected – the
“then” part of the hypothesis
♦ The variable plotted on the Y axis
Characteristics of a Good
Experiment
1.
2.
3.
4.
5.
6.
7.
Can be repeated the same way and get the same
results
Have a large sample size
Are performed for longer periods of time
Test only one independent variable
Must test the hypothesis and show whether it is right
or wrong
In objective - fact and opinion are not mixed
The experiment follows ethical and legal standards
DATA AND GRAPHS
DATA TABLES are used to organize
data that will be plotted on the graph
 The first column is for the
independent variable
 The second column is for the
dependent variable
 Each column should be titled and
include units of measurement
 Data in the table should be arranged
in ascending or descending order
(according to directions)
Temperature
(ºC)
Hear rate
(beats/min)
5
108
10
150
15
180
20
270
25
300
DATA AND GRAPHS
Y
Both the X and Y axis of the
graph should be labeled or
titled. These should be the
Hear rate
same ones used in the data (beats/min)
table.
Units of measurement must
also be included.
X
Temperature
(ºC)
DATA AND GRAPHS
• The independent variable is always plotted on the X
axis
• The dependent variable is always plotted on the Y axis
• The X and Y axis must be numbered:
∙ Numbers must be in a uniform increment (count by 1’s, 5’s,
10’s, etc)
∙ Your number scales should take up most of the graph
∙ Your numbers must line up with the grid lines of the graph
∙ You do not need to start numbering your axis with zero
∙ Do not plot number values not included in the data table
DATA AND GRAPHS
300
∙
∙
Heart Rate (beats/min)
• To date, all graphs have
been line graphs. If you
draw a bar graph, you
not receive any credit.
• All plotted points must
be surrounded by a circle
(or square or triangle)
according to the
directions.
200
∙
∙
100
0
∙
5
10
15
20
Temperature (°C)
25
UNIT II
CHARACTERISTICS of LIVING THINGS
• CHEMISTRY (carbohydrates, lipids,
proteins, enzymes, acids and bases)
• HOMEOSTASIS, METABOLISM, and
LIFE PROCESSES (including photosynthesis
and respiration)
• CELLS
CHEMISTRY
The most common elements in living things are
(in order)
Carbon
Hydrogen
Oxygen
Nitrogen
Organic Compounds
Have Carbon and Hydrogen
(C6H12O6 is organic H2O is not)
Organic molecules are larger than inorganic
molecules
Inorganic Compounds
WATER IS THE MOST IMPORTANT
INORGANIC COMPOUND
Examples of Organic Compounds
Carbohydrates are sugars and starches
• All carbohydrates are made from simple sugars
(their building blocks) like glucose
• They supply quick energy for the body
• Enzymes can break down carbohydrates into
simple sugars
Examples of Organic Compounds
Lipids include fats, oils, and waxes
• Lipids are made of 3 fatty acids and 1 glycerol
• Lipids are a source of stored energy for the body
• Enzymes can break down lipids into fatty acids
and glycerol
Examples of Organic Compounds
Proteins include muscle fibers, hormones, enzymes,
hemoglobin
• Proteins are made from amino acids
• Proteins make most of the chemicals used to build
and run the organism’s body
• Proteins, as far as your body is concerned, are the
most important of the three organic molecules
• It is the shape of proteins and how they fit together
with other molecules that determine what proteins
can do.
PROTEINS continued
Four specific jobs of
proteins:
1. Enzymes (see next
slide)
2. Transport molecules in
the cell membrane
3. Antibodies which fight
infection
4. Hormones which are
chemical messengers
PROTEINS continued
Enzymes are catalysts made from proteins
• Catalysts affect the rate (speed) of chemical
reactions
• Lock and Key Model demonstrates how the
specific shape of an enzyme fits one and only one
type of molecule (substrate)
PROTEINS continued
If the protein loses its shape, it will not longer
work
At high temperatures, proteins (enzymes) loss their
shape - that is why high temperatures are
dangerous
When this occurs, we say the enzyme is denatured
ACIDS and BASES
• The pH scale measures the strengths of acids
and bases
• A low pH (0-6) is an acid
• A high pH (8-14) is a base
• A pH of 7 is neutral (water)
CHARACTERISTICS of LIVING THINGS
HOMEOSTASIS
• Homeostasis is a balanced state in an organism
• Dynamic equilibrium means that the body stays
balanced by taking action whenever the balance
is disturbed (like sweating when the body is too
hot)
• To maintain homeostasis, organisms carry out
the same basic life functions:
TRANSPORT, NUTRITION, EXCRETION,
RESPIRATION, GROWTH, SYNTHESIS,
REGULATION (know these terms!)
CHARACTERISTICS of LIVING THINGS
TRANSPORT
• DIFFUSION: movement of molecules from areas of
high concentration to areas of low concentration.
Requires no energy (passive transport)
• ACTIVE TRANSPORT: requires energy, usually
movement of molecules from areas of low
concentration to areas of high concentration
(against the natural flow of diffusion)
• OSMOSIS: is the diffusion of water molecules into or
out of a cell. If water flows in (a cell in pure water), the
cell will swell and maybe burst. If water flows out (a
cell in salt water), the cell will shrivel up.
CHARACTERISTICS of LIVING THINGS
NUTRITION
AUTOTROPHS make their own food
HETEROTOPHS eat other organisms
PHOTOSYNTHSIS is carried out by green plants, algae,
and some bacteria (autotrophs)
Plants make capture the sun’s energy to change inorganic
materials into organic materials (food)
CO2 + H2O → C6 H12O6 + O2 + H2O
Photosynthesis occurs in the chloroplasts of the plants’
cells
NUTRITION in PLANTS
• Plants have stomates (holes) in their leaves that
let them exchange the gasses used in
photosynthesis. Guard cells open and close the
openings to keep the plant from dehydrating.
• Xylem carries water, and Phloem carries food
through the plant
HUMAN NUTRITION
• The digestive system is a one-way passage
through the body that includes the mouth –
esophagus – stomach – small intestine – large
intestine – rectum – anus
• Food is broken down by both mechanical and
chemical digestion
• Food is moved through the digestive system by
muscular contractions called peristalsis
• Undigested solid wasted is eliminated as feces
HUMAN NUTRITION
A. MOUTH
Mechanical digestion and chemical digestion
of starch
B. ESOPHAGUS
Food tube to the stomach
C. STOMACH
Begins protein digestion – acidic environment
D. SMALL INTESTINE
Digestion completed – absorption of nutrients
E. LARGE INTESTINE
Water and vitamin absorption
HUMAN NUTRITION
DIGESTIVE ACCESSORY ORGANS
• LIVER: produces bile (emulsifies fat)
• GALL BLADDER: stores bile
• PANCREAS: produces a whole spectrum of
enzymes that complete chemical digestion in the
small intestine – pancreatic juice also neutralizes
the acidic chyme
Some clarification:
• Solid waste is eliminated from the your body via
the digestive tract – excretion is of cellular
metabolic waste and is produced by the kidneys.
• The digestive system gives the body nutrients –
energy is produced only by cellular respiration in the
cells
Cellular Respiration
The process by which organisms take energy from the
bonds in glucose molecules (breaks it down) and places
it in ATP. ATP is the energy source of all living things.
 AEROBIC RESPIRATION requires oxygen and yields
more ATP (energy) from glucose than anaerobic (no
oxygen) respiration does.
C6 H12O6 + O2 → H2O + CO2 + ATP
 AEROBIC RESPIRATION occurs in the
mitochondria of the cells.
Cellular Respiration
ANAEROBIC RESPIRATION (fermentation)
occurs when oxygen is not available.
Less ATP is produced
When human muscle cell are fatigued, anaerobic
respiration begins and the product, lactic acid
builds up which causes “burning” and aching
muscles the next day.
ANAEROBIC RESPIRATION also occurs in
yeast and some bacteria cells.
CELLULAR RESPIRATION vs.
PHOTOSYNTHESIS
 They are opposite reactions
 They are important in recycling oxygen, carbon, hydrogen,
and water through the environment.
CO2 + H2O → C6 H12O6 + O2 + H2O
C6 H12O6 + O2 → H2O + CO2 + ATP
 ALL organisms, including plants, perform cellular
respiration to get their energy
 Respiration is not breathing (that’s gas exchange or getting
oxygen for respiration). Respiration is obtaining energy
from glucose molecules
 Organisms that perform anaerobic respiration do not need
oxygen (or need to breath) to live
CELLS
 Cells are the basic unit of life. All living things
(except viruses) are made of cells.
 The cell theory states:
1.
2.
3.
All living things are made of one or more cells
Cells carry out all of an organism’s life functions
All cells come from other living cells
Cell Organelles (and their functions)
1. Cell membrane – controls what comes in and
out of the cell
2. Cell wall – protection and shape
3. Nucleus – control center of the cell (DNA)
4. Chloroplast – site of photosynthesis
5. Cytoplasm – jelly like substance the organelles
are suspended in
6. Ribosome – site of protein synthesis
7. Vacuole – storage
8. Mitochondria – site of cellular respiration
PLANT vs. ANIMAL CELLS
•
•
•
•
Plant cells have cell walls, animal cells do not
Both plant and animal cells have cell membranes
Animal cells have centrioles, plant cells do not
Animal cells usually have small vacuoles, plant
cells usually have a few and larger
THE CELL MEMBRANE
• Made of lipids and proteins
• Is selectively permeable
– Small molecules can pass through it (O2, H2O, CO2, glucose, amino
acids)
– Large molecules pass through with the help of transport proteins
(proteins and starches)
• If the membrane uses ATP to move a molecule through the
membrane, it is active transport.
Proteins in the
Membrane
1. Receptor proteins
2. Transport proteins
3. Antigens (markers)
UNIT III
HOMEOSTASIS AND THE
HUMAN BODY
• THE ORGANIZATION of LIVING THINGS
• HUMAN BODY SYSTEMS
• DISEASES and DISORDERS
ORGANIZATION
ORGANELLS –functional units with the cell
CELLS – basic unit of life
TISSUES – groups of cells that are specialized to do
certain jobs (including muscle and nerve tissue)
• Specialization or differentiation is the process that changes a
stem cell into a specialized cell
• Stem cells are cells that have not yet been specialized
• Almost all cells have a complete set of genes, but only those genes
needed for the cells’ particular job are “turned on”.
ORGANS – tissues working together (heart, lungs,
kidneys)
ORGAN SYSTEMS – organs working together (digestive
system, circulatory system)
ORGANISM
TRANSPORT
Human Circulation
The circulatory system moves material (water,
gasses, nutrients, hormones, wastes) through
the body to the cells that need them.
The main parts of the circulatory system are:
1. THE HEART
2. BLOOD
3. BLOOD VESSELS
Human Transport
Components of the Blood:
1. RED BLOOD CELLS:
carry oxygen on hemoglobin
2. WHITE BLOOD CELLS:
fight disease
3. PLATELETS: small
fragments that clot the
blood
4. PLASMA: liquid part of the
blood that carries everything
except oxygen
HUMAN TRANSPORT
The Heart
Parts of the heart
• Chambers
• Vessels
Blood flow through the
heart
• Vena cavas – right atrium –
right ventricle – pulmonary
arteries – lungs – pulmonary
veins – left atrium – left
ventricle – aorta – tissues of
the body
HUMAN TRANSPORT
Blood Vessels
ARTERIES:
• Structure – thick and muscular (where
pulse and blood pressure is taken)
• Function – carries blood away from
the heart
• Blood type – oxygenated (except
pulmonary artery
VEINS:
• Structure – thin and nonmuscular
• Function – carries blood towards the
heart
• Blood type – deoxygenated (except the
pulmonary vein
CAPILLARIES:
• Structure – one cell thick
• Function – site of diffusion of
materials between the blood and body
cells
RESPIRATORY SYSTEM
• Breathing provides oxygen
needed for cellular
respiration (which releases
energy from sugar)
• You breathe faster when
CO2 builds up in the blood.
• The alveoli are the
microscopic air sacs
surrounded by capillaries
(the respiratory surface)
where gas exchange occurs
CO2
O2
RBC
HUMAN RESPIRATORY
SYSTEM
• The diaphragm is the muscle that allows breathing
REGULATION
• A stimulus is a change in the environment that
you respond to.
• A neuron is a nerve cell.
• An impulse is the electrical signal carried by
nerves – neurotransmitters are chemicals that
transfer the impulse from neuron to neuron.
• A hormone is a chemical signal secreted by
different glands in the body.
Receptor molecules are proteins on the surface
of the cell membrane that receive signals from
the nervous and endocrine system. These are
needed for your cells to communicate and work
together.
As with all proteins, it is the shape of the receptor
molecule that determines its function (or
determines what signal it will receive)
Endocrine
gland
hormone
Target cell
Non-target cell
THE NERVOUS SYSTEM
• The nervous system
regulates your body with
electrochemical impulses
• The central nervous
system = the brain and
spinal cord
• The peripheral nervous
system = all the other
nerves in the body
THE NERVOUS SYSTEM
(the reflex arc)
• The spinal
cord controls
reflexes and
relays
information
between the
body and the
brain
THE ENDOCRINE SYSTEM
• Hormones regulates the body.
• Slower than the nervous system but effects last
longer.
• The pancreas makes insulin which lowers blood
sugar.
• Adrenal glands make adrenaline when the body
is under stress.
• Testosterone (male) and estrogen and
progesterone (female) are the sex hormones.
They are made in the gonads (testes and ovaries)
Endocrine
System
• Hormones levels are
controlled by feedback
mechanisms
Higher blood sugar
Pancreas secretes
less insulin
Pancreas secretes
more insulin
Lower blood sugar
THE IMMUNE SYSTEM
• The job of the immune
system is to protect the body
against pathogens.
• Types of pathogens include
viruses, bacteria, and
parasites.
• White blood cells are the
main components of the
immune system.
Different White Blood Cells have
different roles, including:
1.
2.
3.
4.
5.
Identify pathogens
“Tag” pathogens for destruction by other WBC’S
Destroy the pathogen by eating it
Destroy the pathogen using chemicals
Make antibodies
WHITE BLOOD CELLS
An Immune Response
• Antigens are protein “tags”
that can be used to identify a
cell or virus
• Cells or viruses that have a
antigens different than yours
will cause an immune
response.
• Antibodies are also proteins
made by white blood cells to
attack antigens.
• Each antibody attacks a
specific antigen – this is
determined by its shape.
Be sure you can…
1. Explain why your body’s immune system
rejects organ transplants.
2. Explain why blood type O is the universal
doner: type AB is the universal recipient.
3. Remember that antibodies are proteins, not cells.
4. Remember that antibodies and antigens are specific
to each other based on their shape.
VACCINES
• A vaccine is an
injection of a dead or
weakened pathogen.
It is effective against
both viruses and
bacteria.
• Vaccines do not
cure diseases, they
prevent you from
getting a disease.
ANTIBIOTICS
• Antibiotics are drugs used to stop infections by
bacteria. Antibiotics will not work against
viruses. Antibiotics can cure diseases.
EXCRETORY SYSTEM
• Removes metabolic waste
 Including salt, water, urea,
and carbon dioxide
• Lungs secrete CO2 and water
• Skin secretes sweat
• Kidneys filter waste from
blood and reabsorb nutrients
• Liver filters toxins and dead
red blood cells from blood
INTERACTION BETWEEN
HUMAN SYSTEMS
BE ABLE TO EXPLAIN HOW DIFFERENT SYSTEMS OF THE
BODY WORK TOGETHER TO MAINTAIN HOMEOSTASIS
I.
Nutrients from the digestive system are transported to
the cells by the circulatory system
II. Wastes from the respiratory system are removed by
the excretory system
III. The nervous and endocrine system work together to
control the body
IV. The immune system protects the nervous system
from disease
DISEASES AND DISORDERS
Be familiar with different diseases and disorders,
what causes them, and how they may affect the
body. Don’t worry about memorizing all of
them. Typically the exam asks you to name a
disease and how it disrupts homeostasis.
Here are some examples for you to know:
AIDS
• Caused by HIV (it is a virus/pathogen)
• Weakens human immune system ;leaving the
body vulnerable to other diseases
• Spread through bodily fluids, usually sexual
contact, intravenous (IV) drug use (sharing
needles), or blood transfusions
• No cure, but the spread may be prevented by
sexual abstinence, “safe” sex (using condoms),
not sharing needles, blood testing before
transfusions
CANCER
• Caused when a cell reproduces (divides) at an
uncontrolled rate, forming a tumor
• Cancer cells to not specialize and take nutrients
from healthy tissue
• May be caused by radiation, chemicals (asbestos
or cigarette smoke) and viruses
• Treatments include surgery, radiation and
chemotherapy
DIABETES
• Affects the body’s ability to control blood sugar
• The pancreas does not produce insulin
(normally used to decrease blood sugar)
• Some diabetics may be treated by using
injections of insulin made by genetically
engineered bacteria
ALERGIES
• Occur when the immune system reacts to an
otherwise, harmless, substance (such as pollen)
the same way it would a harmful pathogen (such
as a cold virus)
• Asthma is a form of an allergic reaction
UNIT IV
REPRODUCTION
• Asexual and sexual reproduction
• Mitosis and meiosis
• Human reproduction and development
Sexual and Asexual Reproduction
ASEXUAL REPRODUCTION
SEXUAL REPRODUCTION
one parent
two parents
faster and easier
more time, effort, risk
no variation
variation due to recombination of genes
offspring the same as parent
offspring different from parents
Mitosis
and
Meiosis
Mitosis and Meiosis
MITOSIS
MEIOSIS
used in all forms of asexual reproduction
used in growth and repair
makes gametes for sexual reproduction
number and type of chromosomes in the
daughter cell are the same as in the parent
separates the homologous chromosomes so
that the offspring get one chromosome
from each parent (half the number of
chromosomes in the daughter cells)
one cell division
two cell divisions
results in 2 identical diploid (2n) cells
Results in 4 different haploid (n) cells
Mitosis
MALE REPRODUCTIVE
SYSTEM
• Testes produce
and store sperm
• Testosterone is
the male sex
hormone – it is
made in the testes
FEMALE REPRODUCTIVE SYSTEM
•
•
•
•
Ovaries produce eggs
The fallopian tube carries the egg to the uterus
The uterus is the womb where the baby will develop
The vagina is the birth canal where the baby will leave
the body
FEMALE REPRODUCTIVE
SYSTEM
• The menstrual cycle lasts 28
days (on average)
 Ovulation – release of an
egg (typically 1 per cycle)
 Menstruation – shedding of
the uterine wall
 If pregnancy does occur, the
menstrual cycle will
temporarily stop.
EARLY DEVELOPMENT
EARLY DEVELOPMENT:
•Fertilization forms a
single cell called a zygote
•The process of cleavage
begins (no growth between
mitotic cell divisions)
•A solid ball of cells forms
called a morula
•The blastula forms next
when the center becomes
fluid filled
•Eventually a gastrula is
formed
LATE HUMAN
DEVELOPMENT
• The fetus here is
nearly ready to be
born
• Note the umbilical
cord, placenta and
amniotic sac