How many of the following show vivipary? Pteropus, Camelus, Delphinus, Macropus, Ornithorhynchus, Neophron, Aptenodytes, Rattus, Equus

Options

A. 6
B. 5
C. 8
D. 9

Answer

To determine how many of the listed animals show vivipary (the condition of giving birth to live young rather than laying eggs), we will analyze each animal one by one.

1. **Pteropus (Flying Fox)**: This is a type of bat that gives birth to live young. Therefore, Pteropus shows vivipary.

2. **Camelus (Camel)**: Camels are mammals that also give birth to live young. Thus, Camelus shows vivipary.

3. **Delphinus (Dolphin)**: Dolphins are marine mammals that give birth to live young. Therefore, Delphinus shows vivipary.

4. **Macropus (Kangaroo)**: Kangaroos are marsupials that give birth to live young, which then continue to develop in the mother's pouch. Hence, Macropus shows vivipary.

5. **Ornithorhynchus (Platypus)**: The platypus is a monotreme, which is a group of egg-laying mammals. Therefore, Ornithorhynchus does not show vivipary.

6. **Neophron (Vulture)**: Vultures are birds that lay eggs. Thus, Neophron does not show vivipary.

7. **Aptenodytes (Emperor Penguin)**: Like other birds, emperor penguins lay eggs. Therefore, Aptenodytes does not show vivipary.

8. **Rattus (Rat)**: Rats are mammals that give birth to live young. Thus, Rattus shows vivipary.

9. **Equus (Horse)**: Horses are mammals that also give birth to live young. Therefore, Equus shows vivipary.

Now, let's summarize the findings:
- Pteropus: Viviparous
- Camelus: Viviparous
- Delphinus: Viviparous
- Macropus: Viviparous
- Ornithorhynchus: Not viviparous
- Neophron: Not viviparous
- Aptenodytes: Not viviparous
- Rattus: Viviparous
- Equus: Viviparous

Counting the viviparous animals, we find:
- Pteropus
- Camelus
- Delphinus
- Macropus
- Rattus
- Equus

Thus, a total of **6 animals** show vivipary.