Reproductive system Flashcards
Advantages and disadvantages of asexual reproduction
Faster and easier; less variety
Advantages and disadvantages of sexual reproduction
More variety; more time, more effort and risk
What is mitosis for?
All body (somatic) cells. Used in all forms of asexual reproduction.
What is meiosis?
Makes gametes (sex cells). Uses pairs of homologous chromosomes.
Chicken egg vs Human egg
Chicken eggs have food in the yolk. Human eggs use the placenta and are more warm (uterus). Humans also have umbilical cords
What are the four parts of an egg?
Chorion, amnion, allantois, yolk sac
What does the Chorion do?
Surrounds and anchors the embryo (external development)
What does the amnion do?
Contains fluids which act as a cushion
What does the allantois do?
Stores waste. It is an outgrowth of the gut.
What does the yolk sac do?
Encloses the yolk
Internal vs external reproduction
Internal: less children, more safe, on land
External: vulnerable eggs, more offspring, outside of the body, little parental care
Who is Ernest Everett Just?
Discovered that sperm has a binding site to the zona pellucida.
What is parthenogenesis?
A form of asexual reproduction in which an egg develop into an embryo without sperm.
What is fertilization?
The fusion of a sperm with an egg
