Important Questions: Reproduction in Animals - Free MCQ Test with solutions

Asexual reproduction is a type of reproduction where offspring are produced without the fusion of gametes (sperm and egg). Instead, a single organism can reproduce on its own, creating genetically identical offspring (clones).

B is incorrect because it describes sexual reproduction, where male and female gametes fuse.

C is incorrect because asexual reproduction occurs in both plants and animals, not just in plants.

D is incorrect because it refers to sexual reproduction, where gametes fuse, often being dissimilar (male and female).

A is correct: The human female egg cells (oocytes) begin to mature and are available for release starting at puberty.

B is correct: The two ovaries alternate in releasing egg cells, though both ovaries do not release eggs simultaneously.

C is correct: Typically, one egg is released from the ovary every 28 days during a woman's menstrual cycle.

D is incorrect: An egg cell (ovum) typically survives for about 12 to 24 hours after ovulation. It does not live for a month.

The correct sequence in the formation of a baby is as follows. Zygote →  Embryo → Foetus → Baby

• Zygote: The fertilized egg, formed after the sperm and egg fuse.
• Embryo: The early stage of development after the zygote, where the basic body structures begin to form.
• Foetus: The later stage of development, where the organism starts to resemble a baby and organs continue to develop.
• Baby: The final stage after birth, when the organism is fully developed and capable of independent life.

- In animal reproduction, the zygote is the initial cell formed when two gametes (sperm and egg) merge during fertilization.
- This single-celled zygote undergoes numerous cell divisions through a process called mitosis.
- It develops into an embryo, eventually growing into a new individual.
- A zygote contains a complete set of genetic material, combining DNA from both parents, enabling it to develop into an organism.
- Hence, the zygote is the stage that evolves into a new individual.

Options I and III are true of comparison of sexual and asexual reproduction.

Sexual reproduction - It involves two individuals, where two different gametes fuse together (male gamete fuses with female gamete).
Asexual reproduction - It involves only one individual; the offspring has same characters as parents.

The animals that produce new young ones are called viviparous animals.

Explanation:

Viviparous animals give birth to live young, unlike oviparous animals, which lay eggs. In viviparous animals, the embryo develops inside the mother's body, receiving nourishment directly until birth. Examples include most mammals, like humans, dogs, and cats.

The correct answer is:

Frog

Explanation: External fertilization occurs when the fusion of sperm and egg happens outside the body of the organism, usually in a water environment. Frogs show external fertilization, where both male and female release their gametes into water, and fertilization takes place outside their bodies. In contrast, humans, cows, and hens undergo internal fertilization, where fertilization happens inside the female body.

P is ovulation, Q is implantation and R is fertilization.

• Ovulation: This occurs around the middle of a woman’s menstrual cycle. The ovary releases a mature egg (ovum) into the fallopian tube. This egg is available for fertilization.

• Fertilization: Fertilization occurs when sperm from the male meets and penetrates the egg in the fallopian tube. The sperm and egg combine to form a fertilized egg (zygote), which carries the genetic material from both parents.

• Implantation: After fertilization, the zygote divides and forms a blastocyst as it travels down the fallopian tube towards the uterus. Once it reaches the uterus, the blastocyst attaches itself to the uterine lining (endometrium), where it implants. This marks the beginning of pregnancy.

Hydra reproduce by asexual mode. Budding is the process by which hydra reproduce through asexual mode. An outgrowth grows from the parent body due to the repeated cell division at a specific site. The cell which divide rapidly are known as regenerative cell. The outgrowth from the parent body is known as bud. This bud separates from the parent and develops into a genetically identical new organism.