Question

Which reproductive adaptation is characteristic of most terrestrial vertebrates but not of most aquatic vertebrates?

• A. External fertilization
• B. Internal fertilization
• C. Motile gametes
• D. External development

Answer 1

Answer: (B)

Internal fertilization

Most vertebrate animals that live on land have an adaptation that allows internal fertilization, where by the male penis inserts sperm directly in the female body. This is advantageous since, sperm need liquid to swim and the moist female reproductive tract provides this. External fertilization is seen in aquatic vertebrate animals which live in water so sperm can easily be deposited in the water and swim to the female reproductive tract. Motile gametes are found in both terrestrial and aquatic vertebrates. External development is mainly seen in aquatic vertebrates.

Therefore, the correct answer is option B.