The fact that the sperm and the egg fused to create a zygote while inside the female body, is reason to state that the answer is "<u>internal fertilisation</u>".
Asexual reproduction does not occur in crocodiles, and the other option of external fertilisation would occur in frogs, where the female lays eggs in a pond, and a male frog will fertilise it at a later stage.
Asexual: Offspring arise from single organism Sexual: Genetic information from two organisms (male and female), where one produces a motile gamete (male) that travels to fuse with a larger stationary gamete produced by other (female). Internal Fertilization: Union of an egg cell with a sperm during sexual reproduction inside the body of a parent. External Fertilization: The sperm cell reunites with the egg cell in the open, rather than inside the body of a parent.
:) I'm sure you can figure it out from the information I stated above
Oxygen is carried both physically dissolved in the blood and chemically combined to hemoglobin. Carbon dioxide is carried physically dissolved in the blood, chemically combined to blood proteins as carbamino compounds, and as bicarbonate.
Natural selection progresses slowly & would take generations to complete while artificial selection may complete within days or weeks. This is because Natural selection is not as controlled as artificial selection.