Transcript Plants & Animals

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 (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.
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
• 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 dessication. They need
water to reproduce.
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.
• 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
• 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.
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 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.
• 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.
•Invertebrates
- No backbone
Porifera – sponges
• Assymmetrical (no symmetry)
• Sessile (attached) as adults
• Reproduce by fragmentation
• Filter feeders
Cnidaria – jellyfish, sea anemones, corals,
portuguese man-o-war
• jelly-like
• no specialized organs
• 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
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
• 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
Echinoderms – starfish, sea urchin, sand
dollar
* marine animals, plates with spines,
radial symmetry
Nonvertebrate Chordates
Chordates
•Vertebrates
- backbone
Fishes – salmon, tuna, sharks, rays, etc.
*aquatic, most are marine
Amphibians – frogs, caecilians,
salamanders
*Wide variety of habitat, typically start out
as larva living in water
Reptiles- snakes, turtles, iguana
*dry, scaly skin protects against
dehydration
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)
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.