4th
NINE WEEKS FINAL EXAM REVIEW – ANSWER KEY
1. What is an adaptation? Over several
generations, an organisms ability to change and adapt to new environments in
order to survive.
2. Why do species adapt? To survive
and reproduce!
3. What is the definition of natural selection? The gradual, non-random,
process by which biological traits become either more or less common
in a population
4. What is the adaptations cactus has made in
order to survive its harsh conditions? (Spikes,
store water, waxy surface, adapted roots, etc)
5. Define dominant allele. A dominant
allele is an allele where its phenotype will always be represented
when the allele for that gene is present.
6. Define recessive allele. A recessive allele can be
masked by a dominant allele when a dominant and recessive allele are present
for the same gene.
7. What is the difference between a dominant and
recessive allele when crossed? The dominant trait will show up in the
phenotype. Dominant allele in capitalized.
8. What is heterozygous? One dominant
allele and a recessive allele.
9. What is homozygous? Two of the same alleles.
10. What is a punnett square used for? To
predict the probability of the traits of the offspring.
11. Complete an example of a punnett square when
a male with brown eyes - BB is crossed with a female with blue eyes - bb. What is
the ratio of the offspring? 100%
Brown Eyes
12. What
is a genotype? Give an example. The combination of alleles Ex: Bb
13. What is a phenotype? Give an example. The trait that will be expressed
based on the 2 alleles – 1 from each parent. Ex: Purple Flowers
14. What would cause a species to survive
changing environmental conditions and be able to pass their genes on to their
offspring? A species that
could adapt to the new environment.
15. What are chromosomes? Cellular
structures that are made of DNA that carry information that controls inherited
characteristics.
16. Where is DNA located? Chromosomes
in the nucleus
17. Who is known as the “father of genetics?” Gregor
Mendel
18. How many genes do offspring receive for each
trait? 2… One from each parent.
19. What happens when you get a fever? What
temperatures would be considered a fever? You
sweat. Anything over the normal 98.6
would be a fever.
20. What is homeostasis? The process by which
an organisms internal environment is kept stable during changes in its external
environment?
21. What is a behavioral adaptation? Give an
example.
Behavioral adaption is the things animals do to survive. Like bird
calls or migrating are forms of adapting. When certain species are born they
have to watch their parents or others surrounding them to understand what they
have to do to survive. They have to learn to cope with the weather, enemies,
and environment in a "suvival of the fittest" way.
22.What is a structural adaptation? Give an
example.
Structural adaptations are
physical features of an organism like the bill on a bird or the fur on a bear.
23. What kind of adaptations might an animal have
in response to living in a dry, hot climate like the desert? It
would avoid being active at night and conserve it’s energy for being active at
night.
24. What kind of adaptations might an animal have
to survive cold climates? Two layers of fur, inner layer insulates, outer layer sheds moisture
and protects from wind
25. Why would an animal mimic the defense
mechanism of a similar species? The
other organism may be poisonous so by mimicking the defense mechanism of the
other similar species it can evade predators.
26. How does homeostasis work with your
circulatory system? It helps by increasing the blood flow in your body
27. Describe 4 different beak shapes birds have
adapted to get nutrients from its environment.
a. Crushing
beak for hard seeds
b. Crushing
beak for plants, fruit buds, or leaves
c. Probing
beaks for insects in holes
d. Stabbing
beak for cactus parts and insects
28. What combination of genotypes would express a
dominant trait? A recessive trait?
a. Genotype
express dominant trait – (any letter will work as long as both are capital or
one letter is capital and the other is lowercase) BB or Bb
b. Genotype
express recessive trait – (any letter will work as long as both are lowercase)
bb
29. Define asexual reproduction.
a. Asexual
reproduction – an exact copy of a single parent.
30. Define sexual reproduction.
a. Sexual
reproduction – causes genetic variation from the two parents.
31. What is the difference in the offspring of
asexual and sexual reproduction?
a. Asexual
– offspring are an exact copy of parents.
b. Sexual
– a mixture of both parents.
32. What is the definition of selective breeding?
What is an example?
a. Selective
breeding – the process of breeding plants and animals for particular traits;
synonymous with artificial selection.
b. Examples:
different colored carrots, variegated ears of maize, charolais cattle produce
more red meat and less fat, Chihuahuas and Great Danes are bred for size.
