Turning points 3: Sexual Reproduction

Question 1

What is sexual reproduction?

Answer 1

Alternation between meiosis (creating hapliod forms) and syngamy - Fusion of gametes - (creates diploid forms)

Question 2

What is Asexual Reproduction?

Answer 2

Most organisms reproduce Asexually.
Species:
Bacteria, archaea, many fungi, some animals, and land plants

Bacteria/archaea: binary fission

Eukaryotes: mitosis

Question 3

What is the Red Queen Hypothesis and prediction?

Answer 3

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)

Question 4

What is Isogamy?

Answer 4

Isogamy (ancestral state)
- Gametes equal in size and mobility

Question 5

What is Anisogamy?

Answer 5

Anisogamy (derived state)
- Gametes unequal in size, both still mobile

Question 6

What is Oogamy?

Answer 6

Oogamy (derived state)
- Continued gamete differentiation.
- One gamete is large and immobile.
- One gamete is small and mobile.

Question 7

Advantages of large gametes:

Answer 7

• Well provisioned
• Enough cytoplasm to begin early development of the embryo.
• Increased target size (easier for other gametes to find)

Question 8

Advantage of small gametes:

Answer 8

• Increased mobility (better able to find other gametes)