Question

PRELAB 1. Use your textbook to define the following in your own words: a. Evolution: b. Allele: c. Heterozygous: d. Homozygous: e. Dominant allele: f. Incomplete dominance: g. Natural Selection: h. Sexual Selection 2. What is genetic drift? How does it affect populations? Give an example of an event that would cause drift.

Answer 1

a) Evolution is a gradual & constantly occuring process of change that could lead to new species.
b) Pairs of genes that defines the hereditary features of an organism is called alleles. Example: gene that determines blood type.
c) Heterozygous refers to having one of the each kind of allele. 1 dominant allele & 1 recessive allele.
d) Homozygous refers to having 2 copies of same allele, which means 2 dominant alleles.
e) Dominant allele will express the characteristics it is related to in an individual even if other alleles are present.
f) When the dominant allele doesn't fully mask the influence of the recessive allele, & this causes a physical appearance that is a mixture of both the alleles, it is called incomplete dominance.
g) Natural selection is a process that is crucial for evolution. The organisms with advantageous traits have more chance of reproduction. So that they are able to pass these particular traits to the coming generation. In time, natural selection lets the organisms for adapting to the environment.
h) It is a specific kind of natural selection. An individual selects a mate from the opposite sex for mating by facing competition from the same sex.

hope the answer helps.