Transcript Plant and Animal Notes 2015

PLANTS & ANIMALS
Plants
• Modern land plants are descendants
of green algae. Three obstacles that
land plants had to overcome are
• 1) conservation of water,
• 2) reproduction on land &
• 3) how to absorb minerals from the
surface.
• The 2 groups of modern plants include
1) vascular - these use special tissues
that transport water & nutrients
throughout the plant &
• 2) nonvascular- these have no tissue
& transport nutrients through osmosis
& diffusion.
Groups of Plants
• I. Nonvascular Plants-Bryophytes(mosses)
• II. Vascular Plants
A. Seedless Vascular Plants (ferns)
B. Vascular Plants with Seeds
1. Gymnosperms (pines, cycads)
2. Angiosperms (maples, roses)
NONVASCULAR PLANTS
• Bryophytes – These have no true roots,
stems, or leaves. The life cycle of
bryophytes exhibits an alternation of
generations in which the haploid
gametophyte is the dominant
form. Bryophytes are divided into 3
classes: mosses, liverworts, &
hornworts.
• The mobile reproductive part of nonvascular
plants are spores.
Moss
capsule
liverwort
hornwort
Moss
gametophyte
Moss sporophyte
• The diploid (2n)
phase of the moss
life cycle occurs
when gametes
fuse. The zygote
develops into a
sporophyte, which in
turn produces
haploid spores by
meiosis.
http://www.sumanasinc.com/webcontent/
animations/content/moss.html
Alternation of Generations
Alternation of generations is a pattern of reproduction
occurring in the life cycles of many lower plants and some
invertebrates, involving a regular alternation between two
distinct forms. The generations are alternately sexual and
asexual (as in ferns).
Meiosiswhen the
nucleus
divides in
sexually
reproducing
organisms.
Mitosis-the
process where a
single cell divides
resulting in two
identical cells.
(Asexual
reproduction)
• The gametophytes of liverworts &
hornworts are haploid. Both of these
groups have a life cycle similar to that
of mosses. Liverworts also reproduce
asexually by spores & by the
production of gemmae usually formed
in special gemmae cups.
• Bryophytes have rhizoids that are tiny root-like
structures & cuticles that helps prevent water
loss. They need water to reproduce.
Rhizoids in non vascular plants are
analogous to roots in vascular plants.
*
VASCULAR PLANTS
• The vascular plants developed
specialized vascular tissues as well as
roots, stems, & leaves. These
structures enabled vascular plants to
grow taller, disperse their
reproductive cells more widely, &
withstand harsher conditions than
nonvascular plants.
Roots
• Two main types of roots
– Taproots – found mainly in dicots
– Fibrous roots – found mainly in
monocots
• Two functions of roots
– Anchor a plant in the ground
– Absorb water and dissolved nutrients
from the soil
Stems
• Three functions of stems:
– Produce leaves, branches and flowers
– Hold leaves up in the sunlight
– Transport substances between roots and
leaves
• The vascular tissue of stems lifts water
from the roots to the leaves (xylem) and
sends the products of photosynthesis from
the leaves to other parts of the plant
(phloem)
Leaves
• Main function is photosynthesis (uses
carbon dioxide, water and light to make
glucose)
– The broad, flat surface of leaves
helps increase the amount of sunlight
absorbed by plants
• Other functions of leaves:
– Transpiration
– Gas exchange
Leaves
• Connects with exterior through
stomata – allows CO2 and O2 to
diffuse in and out of the leaf
• Each stoma consists of two guard
cells that control the opening and
closing of the stomata by
responding to changes in water
pressure.
Transpiration
• Transpiration is the loss of
water from a plant through its
leaves.
• The water is replaced by water
drawn into the leaf through the
xylem vessels in the vascular
tissue
Evaporation of water
molecules out of
leaves.
Pull of water molecules
upward from the roots.
Gas Exchange
• Plants keep their stomata open just enough to allow
photosynthesis to take place, but not so much that
they lose an excessive amount of water.
• Guard cells control the stomata through changes in
water pressure.
– when water pressure in guard cells is high, stoma is
open
– When water pressure in guard cells is low, stoma is
closed.
– Without gas exchange, a plant would be unable to
make food.
• In general, stomata open in the
daytime, when photosynthesis is
active, and close at night to
prevent water loss.
• A plant will close its stomata
any time water conservation is
an issue
Seedless Vascular
Plants
• Seedless vascular plants
require water for sexual
reproduction. Whisk ferns,
horsetails, club mosses, &
ferns are living relatives of the
early seedless vascular
plants. Ferns, the most varied
seedless vascular plants, also
commonly reproduce using
spores formed in sori.
Whisk fern
Resurrection
plant
Club
Moss
Fern with sori
fiddlehead
http://www.harcourtschool.com/activity/sci
ence_up_close/416/deploy/interface.html
Vascular Plants with
Seeds
• Seed plants include gymnosperms &
angiosperms the flowering plants. Both produce
seeds that consist of an embryo plant, a
cotyledon (food source) & seed
coat. Gymnosperms were the 1st land plants
with seeds. Their ovules develop naked. The
male gametophyte is called a pollen
grain. Trees produce 2 types of cones: seed
cones (female) & pollen cones (male).
• Examples of gymnosperms include
conifers, cycads, Ginkgo,
sequoias. Conifers have adapted well to
life in cold, arid regions. They do not
require water for reproduction.
• Angiosperms are the dominant plants
on Earth. They are classified as
monocots or dicots. Monocots
contain one cotyledon, parallel veins,
flowers in multiples of 3, & scattered
bundles. They include grass, wheat,
corn, palms, bananas.
• Dicots have 2 cotyledons, netlike
veins, flowers in 4’s or 5’s & bundles
in circles. They include maples,
roses, oaks, tomatoes. Angiosperms
produce seeds & fruits that provide
much of the food essential for animal
life. They enclose their seeds in fruits
that help ensure their survival.
Comparison of
Monocots and Dicots
PLANT TISSUE
• Plants contain 3 kinds of tissue: epidermal
(outer layer), vascular (tube-like), &
ground (cushions & protects). All new
plant cells are produced in specific areas
called meristems. Cells produced in the
root’s apical meristem differentiate into the
epidermis, cortex, & vascular
cylinder. Roots may develop as taproots
or fibrous roots. All roots anchor the
plant, absorb water & minerals, & store
food.
• Stems support plant growth above the
ground & transport water & food between
the leaves & roots. The vascular tissue
found here includes xylem which takes
nutrients from the roots to the leaves &
phloem which takes nutrients from the
leaves to the roots. Herbaceous stems
are supported by turgor pressure. Woody
stems are supported by the wood produced
by secondary growth.
• Most of a plant’s
photosynthetic cells are
contained in the
leaves. Leaves exchange
gases & release water by the
opening & closing of their
stomata which are tiny
pores. Water movement in
plants results from root
pressure, capillary action &
the pull created by
transpiration.
• Capillary action pulls water up into the
xylem. The evaporation of water from the
leaves (transpiration ) causes the pulling of
the water. 90% of the water is lost as vapor
through transpiration. Translocation
occurs when carbohydrates are moved
from the leaves to the roots.
REPRODUCTION IN FLOWERING
PLANTS
• Flowers consist of highly modified
leaves that are specialized to carry out
sexual reproduction. Essential flower
parts include the pollen-producing
anther & the pistil that contains the
ovary. The nonessential flower parts
protect & adorn the reproductive
structures & aid in pollination. They
are called calyx (sepals) & corolla
(petals).
• A perfect complete flower has all the
essential & nonessential flower parts – ex.
roses, lily, tomatoes. An incomplete
flower lacks 1 or more parts – ex. grass,
corn, squash. An imperfect flower has the
reproductive structures of only 1 sex – ex.
holly, persimmon, squash.
• Pollination is the process of
transferring ripe pollen from the
anther (where it is produced) to the
stigma. Each pollen grain contains a
tube nucleus & a generative
nucleus. The generative cell
produces 2 sperm cells.
• In double fertilization, one sperm fuses with the
egg cell while the other fuses with the polar
body. This forms a embryo & endosperm which
nourishes the developing embryo. In selfpollination pollen stays on 1 flower. In crosspollination the pollen is transferred to another
plant of the same species.
• A fruit develops from the ovary of a flower. Fleshy fruits
are attractive to animals, which eat them & then disperse
their seeds. Dry fruits have structures that help carry
their seeds in air & wind currents.
• A fruit is a ripened ovary that contains seeds.
Seed dispersal…
Blackberry Seeds
“Helicopters”
By wind…
By animal…
Why do you think?…
• Simple fruits have a single ovary – ex.
apple, plum, grapes. Aggregate fruits
contain many pistils on the same flower –
ex. strawberry, blackberry. Multiple fruits
have many single fruits that fuse together
to form 1 single structure – ex. pineapple,
corn, fig.
• Seeds are
dispersed by wind,
water, animals, &
explosion. Seeds
usually experience
a dormant period
before
germination.
• Plants produced
asexually have the
same DNA as the
parent plant. Plant
cultivators use
methods of artificial
propagation such as
cutting & grafting.
Vegetative Reproduction
Vegetative reproduction is when new plants
grow from parts of existing plants.
Three categories of plant life
spans
• annuals – flowering plants that complete a
life cycle within one growing season. They
have to be replanted every year. (ex.
Petunia, corn, watermelon)
• biennials – complete their life cycle in two
years. Flowers or fruit show up every other
year. (ex. Cabbage, carrots)
• perennials – flowering plants that live for
more than two years (ex. Apples, clover)
Plant Responses
•The response of plants to
environmental stimuli are called
tropisms.
•Tropisms demonstrate the ability of
plants to respond effectively to
conditions in which they live
Light
•The response of a plant to light is
known as phototropism
• Phototropism causes a plant to grow
toward a light source
Gravitropism
• Gravitropism causes the shoots of a
germinating seed to grow out of the soil against the force of gravity
• It also causes the roots of a plant to
grow with the force of gravity and into the
soil
Response to Touch
•The response of plants to touch is
called thigmotropism.
•An example of thigmotropism is the
growth of vines and climbing plants.
•Invertebrates
- No backbone
Porifera – sponges
• Assymmetrical (no symmetry)
• Sessile (attached) as adults
• Reproduce by fragmentation
• Filter feeders
• Have no tissue and no organs
Cnidaria – jellyfish, sea anemones, corals,
portuguese man-o-war
• jelly-like
• no specialized organs-have only
one body opening; made of 2 layers
of cells
• stinging cells (cnidocytes)
• Most are found in marine water
• Radial symmetry
Platyhelminthes – flatworms
* soft, thin, flatbodies
• Belong to the phylum platyhelminthes. (Plat = flat)
• They are acoelomates (they don’t have body cavities)
• They have bilateral symmetry
• Show cephalization
• Respiration through skin
• Single opening to digestive tract (pharynx)
Nematoda –round worms
* Most are parasitic
Belong to phylum Nematoda
Pseudocoelomates (fluid filled body cavity)
Slender bodies that taper on both ends
Have mouth and anus
Can be free-living or parasitic
*The hookworm is a parasitic nematode worm that
lives in the small intestine of its host. They are
contracted by humans when they go barefoot in
contaminated soil
Round Worms
• Trichinella is the genus of parasitic roundworms of the
phylum Nematoda that cause trichinosis (also known as
trichinellosis).
• Trichinosis is transmitted by eating undercooked pork
and causes abdominal discomfort, nausea, diarrhea,
vomiting, fatigue, and fever.
Annelida
Includes duster worms, earthworms, & leeches
Abundant in all habitats
Have a true coelom fully lined with mesoderm
Body divided into external segments called
metameres (metamerism)
Arthropoda – segmented bodies,
exoskeleton (chitin), jointed appendages
Arthropods
• Insects – beetles, butterfly, ants, etc.
*3 body segments, some have wings
Arthropods
In complete metamorphosis an insect goes
through four distinct stages: Egg-Larva-PupaAdult.
Arthropods
• Crustacean – crab, crayfish, lobster etc.
*2 body segments – live mainly in water
Arthropods
• Arachnid- scorpion, spiders, etc.
*2 body segments, 8 legs, no antennae
Arthropods
• Myriapod – centipede, millipede
*long flat bodies, many legs
Mollusca
* soft-bodied, usually have a shell, unsegmented, have a muscular foot
(for locomotion and anchorage) and mantle (covers the organs of
digestion)
Echinoderms – starfish, sea urchin, sand dollar
* Marine animals, plates with spines, radial symmetry
*They push their stomachs out, spread digestive
enzymes, and bring in digested food.
*Are deuterostomes—anus formed first.
Nonvertebrate Chordates-have the same
characteristics as Chordates except they do not have
vertebrae. Ex. Tunicates, called “Sea Squirts”
Chordates
•Vertebrates
- Have a backbone
- Have endoskeleton
• Fishes – salmon, tuna, sharks, rays, etc.
*aquatic, most are marine
*The first vertebrates were fish.
*Sharks, eels and rays have skeletons made of cartilage.
Amphibians – frogs, salamanders
*Wide variety of habitat, typically start out as larva living
in water
*Ectothermic-cold blooded, body temperature is
regulated by the environment.
Reptiles- snakes, turtles, iguana
*dry, scaly skin protects against dehydration
*Ectothermic-cold blooded, body temperature is regulated
by the environment.
*Do not have to return to water to
reproduce because they have an
amniotic egg.
Birds – toucan, penguin, eagle,
hummingbird
*Have feathers and wings, not all can fly
Mammals – platypus, kangaroos, humans, rodents
* mammary glands, hair, live birth (except
monotremes)
*Endothermic-warm blooded, body regulates the
internal temperature.
Habitat of Animals
• All biomes
Groups of Animals
• Invertebrates (without backbones)
• Vertebrates (with backbones)
Cell Type
• All animals are eukaryotes.
• No animal cells have cell walls.
Uni- or multicellular?
• All animals are multicellular.
Nutrition in Animals
• All animals are heterotrophic.
• They can be filter feeders, predators, parasites,
herbivores, carnivores, omnivores, scavengers, or
detritivores.
Transforming Matter & Energy
• Animals use cell respiration (either anaerobic
fermentation or aerobic respiration) to transform food
particles into useful forms of energy.
Transporting Matter & Energy
• Simple animals use diffusion
• More advanced organisms have circulatory systems.
• Animals may have open or closed circulatory systems.
Eliminating Matter & Energy
• Simple animals use diffusion to remove wastes from their
bodies.
• More advanced animals use excretory systems to remove
wastes (nephridia or kidneys).
Reproduction in Animals
• Some invertebrates reproduce asexually through fission
(stony corals), budding (hydra), fragmentation
(planarians) or regeneration (sponges). Others reproduce
sexually through sperm & eggs.
Reproduction in Animals
• Vertebrates reproduce sexually through sperm & eggs &
may be either internal or external fertilization.
Types of reproduction in animals
• Oviparous-lay eggs that must hatch. Ex. chickens
• Viviparous-internal fertilization and the young are born
alive, attached to a placenta. Ex. humans
• Ovoviviparous-internal fertilization and the young are
born live, but there is no placental connection and the
unborn young are nourished by egg yolk. They are kept
inside the mother until ready to hatch. ex. sharks and rays
Facts about humans as animals:
• Humans possess a heart with 4 chambers to pump
oxygen throughout the body in the blood stream.
• Humans exhibit cephalization--the concentration of
sense organs and nervous system at the anterior
(front/top) end of the body, forming a head and brain.
• Hair and body fat helps mammals retain body heat.