Question

11 explain why each of the following points is true.
a the type of fertilization of an animal is different between animals that live on land and those that live in water.
b the number of eggs produced by an animal is different between animals that have internal and those that have external fertilization
c the number of young that survive differs between animals that have internal fertilization and those that have external fertilization
d the number of young that survive differs between animals that give parental care and those that do not.

Explanation:

Part a

Animals that live in water (like fish, amphibians in water) often use external fertilization where eggs and sperm are released into water. Terrestrial animals (like mammals, reptiles) use internal fertilization (sperm meets egg inside the female) as water isn’t available externally for fertilization. Different habitats (water/land) drive this adaptation.

Animals with external fertilization (e.g., fish) release many eggs into water (low chance of sperm - egg meeting, high predation on eggs). Internal fertilization animals (e.g., mammals) have fewer eggs (sperm meets egg inside, better survival odds for embryos). Reproductive strategy (external vs internal fertilization) affects egg number.

Internal fertilization animals (e.g., mammals) have embryos develop inside the mother, with parental care (e.g., placenta, milk), so more young survive. External fertilization animals (e.g., fish) release eggs/sperm externally, with little to no parental care, so fewer young survive. Parental care and fertilization location (internal/external) affect survival.

Answer:

Animals in water (e.g., fish) use external fertilization (eggs/sperm in water), while terrestrial animals (e.g., mammals) use internal fertilization (no external water for fertilization). Habitat (water/land) dictates fertilization type.

Part b