BIO 370 Exam 2 QUESTIONS AND
ANSWERS RATED A+
True/False: The majority of organisms are sexual. - correct answer ✔✔ True
True/False: Asexual lineages have a sporadic taxonomic distribution and are evolutionarily short-
lived, compared to sexual lineages. - correct answer ✔✔ True
True/False: Cyclic asexuality suggests that asexuality can be advantageous during specific times.
- correct answer ✔✔ True
True/False: There are many known ancient asexual clades. - correct answer ✔✔ False
What does sex do? - correct answer ✔✔ Gene exchange and recombination through zygote
formation
True/False: Genetic mechanisms associated with sexual reproduction decrease genetic variation
among gametes & offspring. - correct answer ✔✔ False
Recombination - correct answer ✔✔ Crossing-over between/independent assortment of
chromosomes during meiosis
Consequence of crossing-over and independent assortment - correct answer ✔✔ Increased
genetic variation between gametes & offspring
Disadvantages (costs) of sex - correct answer ✔✔ a. Cost of meiosis = cost of mates
b. Need to find sexual partner
, c. Sexually transmitted diseases
d. For females: mixing own genes with mutated male genes
e. Breaking up co-adapted gene complexes
Advantages (benefits) of sex - correct answer ✔✔ a. Faster elimination of deleterious mutations
b. Faster evolution (bringing mutations together)
True/False: 50% chance of elimination = an allele coding for sexuality has 50% fitness compared
to asexuality allele - correct answer ✔✔ True
2 aspects of the cost of meiosis - correct answer ✔✔ a. Cost of 50% elimination of allele coding
for sexuality
b. Cost of producing males
Gene view - correct answer ✔✔ Cost of 50% elimination of any gene coding for sexuality
Individual (mother's) view - correct answer ✔✔ Investing into sons instead of asexual daughters
2 principal ways go making gametes - correct answer ✔✔ a. Few, large gametes
b. Many, small gametes
Anisogamy - correct answer ✔✔ Definition: Production of small and large gametes coexist in
same population
Significance: Basis for sex determination and initial inequality
Sexes are tradeoff between: - correct answer ✔✔ a. Reproductive effort
ANSWERS RATED A+
True/False: The majority of organisms are sexual. - correct answer ✔✔ True
True/False: Asexual lineages have a sporadic taxonomic distribution and are evolutionarily short-
lived, compared to sexual lineages. - correct answer ✔✔ True
True/False: Cyclic asexuality suggests that asexuality can be advantageous during specific times.
- correct answer ✔✔ True
True/False: There are many known ancient asexual clades. - correct answer ✔✔ False
What does sex do? - correct answer ✔✔ Gene exchange and recombination through zygote
formation
True/False: Genetic mechanisms associated with sexual reproduction decrease genetic variation
among gametes & offspring. - correct answer ✔✔ False
Recombination - correct answer ✔✔ Crossing-over between/independent assortment of
chromosomes during meiosis
Consequence of crossing-over and independent assortment - correct answer ✔✔ Increased
genetic variation between gametes & offspring
Disadvantages (costs) of sex - correct answer ✔✔ a. Cost of meiosis = cost of mates
b. Need to find sexual partner
, c. Sexually transmitted diseases
d. For females: mixing own genes with mutated male genes
e. Breaking up co-adapted gene complexes
Advantages (benefits) of sex - correct answer ✔✔ a. Faster elimination of deleterious mutations
b. Faster evolution (bringing mutations together)
True/False: 50% chance of elimination = an allele coding for sexuality has 50% fitness compared
to asexuality allele - correct answer ✔✔ True
2 aspects of the cost of meiosis - correct answer ✔✔ a. Cost of 50% elimination of allele coding
for sexuality
b. Cost of producing males
Gene view - correct answer ✔✔ Cost of 50% elimination of any gene coding for sexuality
Individual (mother's) view - correct answer ✔✔ Investing into sons instead of asexual daughters
2 principal ways go making gametes - correct answer ✔✔ a. Few, large gametes
b. Many, small gametes
Anisogamy - correct answer ✔✔ Definition: Production of small and large gametes coexist in
same population
Significance: Basis for sex determination and initial inequality
Sexes are tradeoff between: - correct answer ✔✔ a. Reproductive effort
