Lecture 14: Reproductive Strategies Flashcards
(12 cards)
Types of plant asexual reproduction:
- Vegetative reproduction
- Parthenogenesis
Vegetative reproduction
Offspring arise from non-reproductive tissue.
Occurs in many plants, some animals (coral, hydra).
Parthenogenesis
Production of embryo without fertilization.
Occurs in plants, aphids, some insects.
Sexual reproduction:
Fusion of two haploid germ cells forms a diploid zygote.
Female
Produces the egg (larger gamete)
Male
Produces the sperm (smaller gamete)
What is the female cost of meiosis?
For the same amount of investment in eggs, sexual females will have half the number of her genes passed down compared to asexual individuals.
How can the female cost of meiosis be offset by hermaphrodites and/or paternal care?
Hermaphrodites: contribute one set of genes through its male function and another set of genes through its female function.
Paternal care: male assistance can help females rear/produce more offspring.
What is the cost of mating for males?
Attracting females may also attract predators or increase competition (ex. singing, fighting others for mates, bright colors, more resources to grow bigger, etc.).
What is the cost of mating for females? (Non-meiotic).
When males are unrelated, they tend to be much more aggressive and can reduce longevity for females and she produces less offspring.
A female can produce more offspring if mating with multiple males who are related to each other.
Why would males be more aggressive competing against unrelated males than related males?
Overall (inclusive) fitness includes “indirect fitness.” Males still get to pass down some of their genetics even if they aren’t the sire because they share DNA with those related to them.
Inclusive fitness = direct fitness + indirect fitness
Direct fitness: Biological offspring
Indirect fitness: Biological offspring of related individuals
