Natural Selection is sometimes described as \"survival of the fittest\" which be

Question

Natural Selection is sometimes described as "survival of the fittest" which best measures an organisms fitness
a) how many fertile offspring it produces
b) its mutation rate
c) how strong it is when pitted againts other species
d)its ability to withstand environmental extremes
e) how much food it is able to make or maintain


Mutations are rarely the cause of evolution in populations of plants and animals because
a) they are often harmful and do not get passed on
b) they do not directly produce most of the genetic variation present in a diploid population
c) they occur very rarely
d) they are only passed on when they occur in cells that lead to gametes
e) all of the above

In an area of erratic rainfall , a biologist found that grass plants with alleles for curled leaves reproduced better in dry years , and plants with alleles for flat leaves reproduced better in wet years. This situation would tend to:
a) cause genetic drift in the grass population
b) preserve genetic variation on the grass population
c) lead to stabilizing selection in the grass population
d) lead to uniformity in the grass population
e) cause gene flow in the grass population

Which of the following pairs of structures is least likely to represent homology
a) the hemoglobin of a human and that of a baboon
b) the mitochondria of a plant and that of an animal
c) the wings of a bird and those of an insect
d) the tail of a cat and that of an alligator.
e) the foreleg of a pig and the flipper of a whale

Explanation / Answer

1. D-Natural selection refers to the ablility of certain genes to prevail in environments. Mating occurs with the strongest and best of the animal world, so body sizes, coloring, calls, and so on all determine which animal you mate with. The weak don't reproduce, because they aren't desirable, so these genes aren't passed on. 2. E- Mutations that are passed on must occur with sex cells during meiosis (most often during crossing over). Mutations that occur during development are not passed on because 1) most often in the animal world, organisms with mutations are stillborns or die soon out of the womb and 2) back to natural selection, other species members will not mate with them. 3. I'm pretty sure its B, but you should double check. This is because if the grass doesn't have the alleles to make flat or curled leaves, in dry or wet years, the grass population would die and probably not recover, so genetic variation is necessary to maintain a healthy population. 4. C- Definition of Homology is a structural correspondence most often from a common ancestor

Related Questions

Navigate

• Browse (All)
• Browse N
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.