Reproduction In Vertabrates

Question 1

External fertilization

Answer 1

HOW IT WORKS :
📣The sperm fertilises the egg outside the body of the female, usually in water.

ADVANTAGES :
📣Water prevents the eggs from drying out and allows the sperm to swim towards the egg.

Question 2

Internal fertilization

Answer 2

HOW IT WORKS :
📣The male deposits it’s sperm inside the reproductive organs of the female and fertilization occurs inside the female’s reproductive organs.

ADVANTAGES :
📣Allows terrestrial animals to reproduce in a dry environment without the need for water. Internal fertilization is more certain than external fertilization.

Question 3

Ovipary

Answer 3

HOW IT WORKS :
📣Eggs are laid and hatching takes place outside the mother’s body.

ADVANTAGES :
📣Egg provides nutrition for the developing embryo and protects the embryo. A shelled egg frees these animals from the need to reproduce in water.

Question 4

Vivapary

Answer 4

HOW IT WORKS :
📣The young develop inside the uterus of the mother after the eggs are fertilised internally.

ADVANTAGES :
📣More efficient development of the embryo as nutrients are received for a longer period from the mother’s blood through a placenta. Embryo is protected in the body of the mother.

Question 5

Ovovivipary

Answer 5

HOW IT WORKS :
📣Young develop from eggs that are fertilised internally and retained within the mother’s body after fertilization until they hatch.

ADVANTAGES:
📣Embryos obtain their nutrients from the egg yolk. The eggs are protected from predators until hatching occurs.

Question 6

Amniote Eggs

Answer 6

HOW IT WORKS :
📣Embryo protected by the shell of the egg; egg consists of many extra embryonic membranes that serve different functions.

ADVANTAGES :
📣Amniote egg protects embryo from dehydration. Yolk sac provides nutrition, Allontois for excretion, chorion for gas exchange.

Question 7

Precocial Development

Answer 7

HOW IT WORKS :
📣Hatchling are quite well-developed when they hatch - eyes open, able to move, able to feed. Brain size and intelligence remains the same throughout their lives.

ADVANTAGES :
📣Hatchlings are more prepared to handle the challenges of the environment ; More independent.

Question 8

Altricial Development

Answer 8

HOW IT WORKS :
📣Hatchling are poorly-developed when they hatch. Unable to feed on their own, cannot move. Brain size and intelligence increases a lot after hatching.

ADVANTAGES :
📣Parental care afforded to protect the young from predators.

Question 9

Parental care

Answer 9

HOW IT WORKS :
📣Parental care afforded through building of nests, protecting the eggs, protecting the young, teaching the young.

ADVANTAGES :
📣Increases chances of survival of the young.