Cycle 7 Flashcards
All About Sex
Q: What is sexual dimorphism?
A: It refers to differences in physical characteristics, behaviors, or physiology between sexes of the same species beyond reproductive organs.
Q: Define isogamy and anisogamy.
A: Isogamy involves equal-sized gametes; anisogamy involves gametes of different sizes, such as small motile sperm and large immobile eggs (e.g., humans).
Q: What is the difference between dioecious and monoecious species?
A: Dioecious species have separate sexes, while monoecious species have both male and female reproductive functions in the same individual.
Q: What is the main advantage of sexual reproduction over asexual reproduction?
A: Sexual reproduction generates genetic diversity by creating new combinations of alleles.
Q: What is Muller’s Ratchet?
A: It is the genetic process where harmful mutations accumulate irreversibly in asexual populations.
Q: Differentiate between intrasexual and intersexual selection.
A: Intrasexual selection (direct competition) is a form of sexual selection where members of the same sex (usually males) compete directly with each other for access to mates, while intersexual selection (choice) involves one sex (often female) choosing mates based on certain traits.
- traits like bright colours, displays, and attraction
Q: Why are females typically more selective in mate choice?
A: Females often invest more energy in reproduction, so selecting high-quality mates maximizes reproductive success.
Q: What is the “cost of males” in sexual reproduction?
A: Only females contribute directly to population growth, making sexual reproduction less efficient than asexual reproduction in increasing population size.
Q: Explain the “Lottery Principle” in the context of sexual reproduction.
A: It states that producing genetically diverse offspring increases the chances of survival in unpredictable environments.
Q: What is sequential monoecy?
A: It is when an individual produces both male and female gametes over their lifetime but not simultaneously (e.g., blue streak wrasse).
Q: Explain the size advantage model of sex change with an example.
A: It predicts that sex change occurs at the size or age where reproductive success is maximized. For example, blue streak wrasses change from female to male as larger males have higher reproductive success.
