BIOB51 TERM QUESTIONS EXAM QUESTIONS AND
ANSWERS WITH COMPLETE SOLUTIONS GRADED A++
LATEST UPDATE
Why sex?
To increase genetic diversity and adaptability.
What did John Maynard Smith mean by the two-fold cost of sex?
Sexual reproduction expends resources on mate search and competition.
What is Muller’s ratchet? What is the relationship between the ratchet analogy
and genetic load?
accumulation of deleterious mutations in asexual populations. The analogy highlights
the irreversible accumulation of genetic load.
Describe how Mike McDonald’s data on fungi demonstrates the differences in
how asexual and sexual populations deal with deleterious alleles.
Asexual populations accumulate deleterious alleles, leading to extinction, while sexual
populations can purge them through recombination.
What is the Red Queen effect? How does it apply to predator-prey relationships?
the need for continuous adaptation to maintain relative fitness. In predator-prey
relationships, it explains the evolutionary arms race where each evolves to outpace the
other.
,How did Curt Lively’s work on snails in New Zealand demonstrate a Red Queen
effect?
coevolution between snails and their parasites led to a continuous arms race,
maintaining genetic diversity.
What is sexual selection? What is the relationship between sexual selection and
natural selection?
selection of traits based on their appeal to mates.
What were the five main topics gleaned from Darwin’s “Descent of Man” book
from 1871 (i.e. Darwin’s dilemma)?
Variation, inheritance, selection, time, and artificial selection.
What is anisogamy?
form of sexual reproduction wherein males and females produce sex cells, or gametes,
of different sizes.
If natural selection underlies adaptation, why are there exaggerated traits that
seemingly decrease survival?
Exaggerated traits often play a role in sexual selection, where they enhance
reproductive success despite potential survival costs.
Explain how the limitations on reproductive success generally differ between the
sexes?
Females typically have a limited number of eggs, while males can produce many sperm.
What is parental investment / parental care?
the resources and effort parents devote to offspring, including care, feeding, and
protection.
, What is meant by uncertain paternity?
inability to determine the true father of offspring, often leading to males investing in
offspring they might not have sired.
What is the operational sex ratio (OSR)? How is it different from the sex-ratio?
Why is looking at the OSR important for studies of sexual selection?
ratio of sexually active males to females. It varies from the sex ratio due to factors like
mate availability and receptivity. Understanding the OSR helps predict the intensity of
sexual selection.
What is meant by the fundamental asymmetry of sex?
The fundamental difference in reproductive investment between males and females,
leading to differences in mating behavior and strategies.
What is intrasexual selection?
Competition between individuals of the same sex for mating opportunities.
What is intersexual selection?
Selection based on traits that attract mates of the opposite sex.
What is the difference between ornaments and armaments and how do they relate
to intrasexual and intersexual selection?
Ornaments are traits that attract mates (intersexual), while armaments are weapons
used in competition (intrasexual).
How does the variance in reproductive success influence the strength of sexual
selection on males and females?
Higher variance in reproductive success leads to stronger sexual selection, typically
affecting males more than females.
ANSWERS WITH COMPLETE SOLUTIONS GRADED A++
LATEST UPDATE
Why sex?
To increase genetic diversity and adaptability.
What did John Maynard Smith mean by the two-fold cost of sex?
Sexual reproduction expends resources on mate search and competition.
What is Muller’s ratchet? What is the relationship between the ratchet analogy
and genetic load?
accumulation of deleterious mutations in asexual populations. The analogy highlights
the irreversible accumulation of genetic load.
Describe how Mike McDonald’s data on fungi demonstrates the differences in
how asexual and sexual populations deal with deleterious alleles.
Asexual populations accumulate deleterious alleles, leading to extinction, while sexual
populations can purge them through recombination.
What is the Red Queen effect? How does it apply to predator-prey relationships?
the need for continuous adaptation to maintain relative fitness. In predator-prey
relationships, it explains the evolutionary arms race where each evolves to outpace the
other.
,How did Curt Lively’s work on snails in New Zealand demonstrate a Red Queen
effect?
coevolution between snails and their parasites led to a continuous arms race,
maintaining genetic diversity.
What is sexual selection? What is the relationship between sexual selection and
natural selection?
selection of traits based on their appeal to mates.
What were the five main topics gleaned from Darwin’s “Descent of Man” book
from 1871 (i.e. Darwin’s dilemma)?
Variation, inheritance, selection, time, and artificial selection.
What is anisogamy?
form of sexual reproduction wherein males and females produce sex cells, or gametes,
of different sizes.
If natural selection underlies adaptation, why are there exaggerated traits that
seemingly decrease survival?
Exaggerated traits often play a role in sexual selection, where they enhance
reproductive success despite potential survival costs.
Explain how the limitations on reproductive success generally differ between the
sexes?
Females typically have a limited number of eggs, while males can produce many sperm.
What is parental investment / parental care?
the resources and effort parents devote to offspring, including care, feeding, and
protection.
, What is meant by uncertain paternity?
inability to determine the true father of offspring, often leading to males investing in
offspring they might not have sired.
What is the operational sex ratio (OSR)? How is it different from the sex-ratio?
Why is looking at the OSR important for studies of sexual selection?
ratio of sexually active males to females. It varies from the sex ratio due to factors like
mate availability and receptivity. Understanding the OSR helps predict the intensity of
sexual selection.
What is meant by the fundamental asymmetry of sex?
The fundamental difference in reproductive investment between males and females,
leading to differences in mating behavior and strategies.
What is intrasexual selection?
Competition between individuals of the same sex for mating opportunities.
What is intersexual selection?
Selection based on traits that attract mates of the opposite sex.
What is the difference between ornaments and armaments and how do they relate
to intrasexual and intersexual selection?
Ornaments are traits that attract mates (intersexual), while armaments are weapons
used in competition (intrasexual).
How does the variance in reproductive success influence the strength of sexual
selection on males and females?
Higher variance in reproductive success leads to stronger sexual selection, typically
affecting males more than females.
