Turning points 3: Sexual Reproduction Flashcards
What is sexual reproduction?
Alternation between meiosis (creating hapliod forms) and syngamy - Fusion of gametes - (creates diploid forms)
What is Asexual Reproduction?
Most organisms reproduce Asexually.
Species:
Bacteria, archaea, many fungi, some animals, and land plants
Bacteria/archaea: binary fission
Eukaryotes: mitosis
What is the Red Queen Hypothesis and prediction?
Hypothesis:
Co-evolutionary interaction between host and pathogens creates ever-changing environmental conditions.
Prediction:
This will favour long-term maintenance of sexual reproduction (especially outcrossing)
What is Isogamy?
Isogamy (ancestral state)
- Gametes equal in size and mobility
What is Anisogamy?
Anisogamy (derived state)
- Gametes unequal in size, both still mobile
What is Oogamy?
Oogamy (derived state)
- Continued gamete differentiation.
- One gamete is large and immobile.
- One gamete is small and mobile.
Advantages of large gametes:
- Well provisioned
- Enough cytoplasm to begin early development of the embryo.
- Increased target size (easier for other gametes to find)
Advantage of small gametes:
- Increased mobility (better able to find other gametes)