Bio 370 Evolution Exam 2 questions
well answered graded A+
sex / sexual reproduction - correct answer ✔✔ Definition:
Exchange of genetic material or recombination via crossing-over/independent assortment
Significance:
Increases genetic variation/diversity among gametes and offspring and can lead to better
fitness, most species reproduce this way at least occasionally.
asexual reproduction - correct answer ✔✔ Definition:
Process of reproduction that does not involve the fusion of gametes
Significance:
Sporadic taxonomic distribution and are evolutionarily short-lived compared to sexual lineages,
very few known ancient asexual clades (bdelloid [leachlike] rotifers)
There will also only be females.
cyclic asexuality - correct answer ✔✔ Definition:
Switching between sexual and asexual reproduction
Significance:
Suggests that asexuality can be advantageous during specific times, sexuality during other times
recombination - correct answer ✔✔ Definition:
,Consequence of crossing over between homologous chromosomes during meiosis or
independent assortment during meiosis
Significance:
Increased genetic variation between gametes and offspring
outbreeding - correct answer ✔✔ Definition:
Type of sexual reproduction where two more distantly related individuals in a population breed
Significance:
More variation among offspring
inbreeding - correct answer ✔✔ Definition:
Type of sexual reproduction where two more closely related individuals in a population breed
Significance:
Less variation among offspring
cost of meiosis - correct answer ✔✔ Definition:
Cost of producing males; for every fertilization event, there is a 50% chance of genetic material
not being passed on (50% elimination of allele coding for sexuality). Only one type of sperm gets
to fertilize an egg, so alleles in the other type of sperm are not passed on at this fertilization
event.
Significance:
This is a disadvantage of sex and producing males (investing/wasting resources on sons instead
of daughters - mother's view). Asexual female offspring of asexual females can reproduce by
themselves but sons of sexual females have to find a mate.
, Disadvantages of sex - correct answer ✔✔ - cost of meiosis (cost of producing males)
- need to find sexual partner
- sexually transmitted diseases
- for females: mixing own genes with mutated male genes
--can poison own relatively unmutated genes with male mutated genes
- breaking up co-adapted gene-complexes
Advantages of sex - correct answer ✔✔ - faster elimination of deleterious alleles
- faster evolution (bringing beneficial mutations together)
--time to bring together multiple beneficial mutations in a single individual is shorter in a sexual
population
Muller's Ratchet - correct answer ✔✔ Definition:
States that more mutations in asexual populations are less easily fixed, and leads to fast
increase in loss of fitness, fastest in smaller populations, but inevitable even in large ones.
Significance:
Supported theory that predicts why asexual populations become extinct faster than sexual
ones. Sexuality (recombination) can reconstitute the least-mutated genotypes that are lost in an
asexual population
origin of sex - correct answer ✔✔ Definition:
The reason for the origin of sex may have been different that the reasons for the maintenance
of sex
1st Theory:
well answered graded A+
sex / sexual reproduction - correct answer ✔✔ Definition:
Exchange of genetic material or recombination via crossing-over/independent assortment
Significance:
Increases genetic variation/diversity among gametes and offspring and can lead to better
fitness, most species reproduce this way at least occasionally.
asexual reproduction - correct answer ✔✔ Definition:
Process of reproduction that does not involve the fusion of gametes
Significance:
Sporadic taxonomic distribution and are evolutionarily short-lived compared to sexual lineages,
very few known ancient asexual clades (bdelloid [leachlike] rotifers)
There will also only be females.
cyclic asexuality - correct answer ✔✔ Definition:
Switching between sexual and asexual reproduction
Significance:
Suggests that asexuality can be advantageous during specific times, sexuality during other times
recombination - correct answer ✔✔ Definition:
,Consequence of crossing over between homologous chromosomes during meiosis or
independent assortment during meiosis
Significance:
Increased genetic variation between gametes and offspring
outbreeding - correct answer ✔✔ Definition:
Type of sexual reproduction where two more distantly related individuals in a population breed
Significance:
More variation among offspring
inbreeding - correct answer ✔✔ Definition:
Type of sexual reproduction where two more closely related individuals in a population breed
Significance:
Less variation among offspring
cost of meiosis - correct answer ✔✔ Definition:
Cost of producing males; for every fertilization event, there is a 50% chance of genetic material
not being passed on (50% elimination of allele coding for sexuality). Only one type of sperm gets
to fertilize an egg, so alleles in the other type of sperm are not passed on at this fertilization
event.
Significance:
This is a disadvantage of sex and producing males (investing/wasting resources on sons instead
of daughters - mother's view). Asexual female offspring of asexual females can reproduce by
themselves but sons of sexual females have to find a mate.
, Disadvantages of sex - correct answer ✔✔ - cost of meiosis (cost of producing males)
- need to find sexual partner
- sexually transmitted diseases
- for females: mixing own genes with mutated male genes
--can poison own relatively unmutated genes with male mutated genes
- breaking up co-adapted gene-complexes
Advantages of sex - correct answer ✔✔ - faster elimination of deleterious alleles
- faster evolution (bringing beneficial mutations together)
--time to bring together multiple beneficial mutations in a single individual is shorter in a sexual
population
Muller's Ratchet - correct answer ✔✔ Definition:
States that more mutations in asexual populations are less easily fixed, and leads to fast
increase in loss of fitness, fastest in smaller populations, but inevitable even in large ones.
Significance:
Supported theory that predicts why asexual populations become extinct faster than sexual
ones. Sexuality (recombination) can reconstitute the least-mutated genotypes that are lost in an
asexual population
origin of sex - correct answer ✔✔ Definition:
The reason for the origin of sex may have been different that the reasons for the maintenance
of sex
1st Theory:
