Please enable JavaScript.
Coggle requires JavaScript to display documents.
Fertilisation - Coggle Diagram
Fertilisation
External
Process
Occurs in aquatic environments
In aqautic environment protects the eggs from drying out.
More opportunities for predation
Greater loss of offspring
#
Once sperm reaches the egg, fertilisation occurs
Eggs and sperm are released into the water
Abiotic factors can encourage release of reproductive material
Eg; sunlight exposure, temperature
Trigger (for egg and sperm release) causes to be placed in small area
Enhances possibility of fertilisation.
Broadcast spawning can result in greater mixture of genes
Higher genetic diversity
Greater chance of species survival
Organisms that use:
Marine animals
Cuttlefish
Staghorn coral
Bony fish
Characteristics
Little to no parental care
Small amount of energy required
High number of gametes released
Low survival rate
Needs water present
#
Avoid dehydration of gametes
Occurs outside of female body
#
Internal
Process
Oviparity
Laid outside the female’s body + develop there
Receives nourishment from the yolk that is a part of the egg
Reptiles and insects produce leathery eggs
These animals are classified as oviparous.
Eggs are fertilised inside female body
Occurs in:
Bony fish
Many reptiles
Most amphibians
Two mammals
All birds
Birds and turtles produce eggs with hard shells
High in calcium
Ovoviparity
Fertilized eggs are retained in the female
Embryo obtains nourishment from the egg’s yolk
Young are fully developed when they are hatched.
Viviparity
Young develop in female body
Receives nourishment from mother’s blood -> placenta.
Occurs in:
Most mammals
Some cartilaginous fish
Few reptiles
Born alive
Organisms that use:
Land animals
Koalas
Red kanagroo
Wallabies
Marine animals
Humpback whale
Saltwater crocodile
Characteristics
Occurs inside female body
Sufficient parental care
Large amount of energy required
Low number of gametes released
High survival rate