A basic overview of what sexual reproduction involves, what meiosis, fertilisation and development are using a hen as an example.

1. Learning Goals:
To be able to explain Sexual Reproduction.
To be able to differentiate the different types
of fertilisation.
To be able to explain different forms of
development.

2. Sexual Reproduction
Sexual reproduction involves two
parents who have sex organs
which produce sex cells.
The sex cells in sexual
reproduction are called
gametes and are produced in
the gonads.
Male gametes are known as
sperm, and female gametes
are known as eggs.

3. Meiosis
A type of cell division that results in
half the required DNA for a new
organism.

4. Meiosis

5. Fertilisation
Fertilization: The fusing of the male
and female gametes to form a zygote.
Internal fertilization: sperm are
transferred from the male directly
inside the body of the female. This is
known as copulation.
External fertilization: Eggs and sperm
are released into the surrounding water.
Occurs in many aquatic invertebrates and
most fish.

6. Development
Development can be external in the water, external on land, or internal.
Oviparous: lay eggs,
offspring develops in egg and
hatches.
(fish, amphibians, reptiles,
all birds, insects, spiders)
Ovoviparous: live
birth from eggs
(some sharks and
snakes)
Viviparous: live placental birth

7. Development

8. Hermaphrodites
Earthworm
Hermaphroditism: individual
has both male and female
reproductive systems.

9. Animal
Location of
Fertilisation
Location of
Development
Number of Eggs
Fertilised
Amount of Parental
Care
Advantages of
reproduction method
Disadvantages of
reproduction method