12 Weeks to TAKS Week 3

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12 Weeks to TAKSWeek 3
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Objective 3 8a-b, 13a
Adaptation and Evolution of Plants and Animals
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All animals and plants have adaptations that help
them survive in their environment.
Examples of Plant Adaptations Support/food
storage Above ground (prop) roots, Stiff cell
walls in stems and trunks (vascular tissue that
also carries water and food), Starch storage in
roots. Prevention of water loss Waxy cuticle,
stomata on leaves, reduced leaf surface area
(cactus), seed coats. Reproduction Seed
dispersal by wind and animals, colors to attract
pollinators, pollen, coevolution with insects.
Defense Toxins, thorns, bark.
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Examples of Animal Adaptations
Protection and prevention of dehydration
exoskeletons, armor, scales, skin,
kidneys. Defense/Predation Claws, teeth, well
developed eye lens, sense of smell, speed,
camouflage, armor, mimicry. Reproduction Eggs,
internal fertilization, placentas, care of young,
nesting.
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Life is very Diverse. Diversity is a measure of
how many different types of organisms live in an
area. For example, a rainforest is a very
diverse habitat (many different species of
insects, plants and animals). A desert is not as
diverse (lots of the same kind of cactus and a
few species of animals). A species is a group
of animals that can breed and produce fertile
offspring. (Poodles and Dalmatians can make
Doodles/Palmations. They are the same species.
Lions and tigers are not. There are no
ligers/tions)
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• Populations of animals adapt to their
  environment by Natural Selection.
• All species have variations (caused by genetic
  makeupMutations can cause variation).
• Variation is inherited.
• More species are produced than will live.
• Those species that survive to reproduce will
  pass their characteristics (genes) on to the next
  generation those that dont become extinct.
• Over time, characteristics and behavior that
  allow the species survive are selected for.
  Unfavorable traits wont be passed on.

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If two populations of organisms become separated
by a barrier, each separate group may have
different selection pressures on it and change in
different ways. Eventually they may not be able
to reproduce and become separate species. This
process is called speciation.
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Phylogenetic Trees are diagrams that show the
relatedness (Phylogeny) of organisms based on
physical and chemical similarities.
A is the common ancestor. B is extinct. E and F
are the most closely related.
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Scientist look at both physical and biochemical
similarities (like DNA and protein comparisons)
to see how organisms are related. Which two
organisms in this chart are the least related?
The silkworm moth and the screwworm fly.
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Polar bears and brown bears have the most bands
of DNA in common and are the most closely
related. Brown and Black bears share 4 bands out
of 9 total. (44.4)