Introduction To Reproduction Flashcards
What is asexual reproduction?
Reproducing with only 1 parent
Offspring have same genotype & phenotype as parent cell
What does genetic fitness rely on?
- Surviving
- Reproducing
What are hermaphrodites?
Both male & female
What is parthenogenesis?
When females lay eggs that develop into offspring without male fertilisation
Give 3 examples of organisms that experience parthenogenesis
- Insects
- Fish
- Reptiles
What are 2 advantages of parthenogenesis?
- Increases population rapidly
- Less energy needed to search for mate
What is a disadvantage of parthenogenesis?
- No genetic variation
What are the 3 mating systems in mammals?
- Monogamy (1 male & 1 female)
- Polygamy (many mates)
- Promiscuity (free for all)
What are the male chromosomes?
XY
What is the female chromosome?
XX
What is mullers ratchet?
Irreversible accumulation of mutations in an asexual population
What is the red queen hypothesis?
Must constantly evolve to survive + reproduce whilst competing opposing organisms in an ever-changing environment
What are the advantages of sexual reproduction?
- Genetic diversity
- Removes harmful genes from population
- Masks bad genes
What is external fertilisation?
Egg + sperm released into water by both sexes at same time & place (broadcast spawning)
What are endothermic homeotherms?
Able to regulate own body temperature
How is body temperature maintained when developing an embryo?
- Develop in eggs incubated by parent
- Develop next to or inside parent
What does precocial mean?
Born at an advanced stage of development
What does altricial mean?
Larger litters but poorly developed & require extra parental investment after birth
Is the gestation period in precocial species longer or shorter than in altricial species?
Longer
What is anisogamy?
2 gametes of different sizes
What is isogamy?
1 gametes of same size
Give one reason suggested for the evolution of anisogamy
If 1 gamete is relatively immobile and the other mobile, the chances of them interacting are increased, i.e. increased encounter rate