Practice Quiz 2 (Reproduction ) - Class 9 MCQ

The correct answer is c

In cell biology, mitosis is a part of the cell cycle when replicated chromosomes are separated into two new nuclei. Cell division gives rise to genetically identical cells in which the number of chromosomes is maintained. In general, mitosis (division of the nucleus) is preceded by the S stage of Interphase.

In asexual reproduction, a new individual is generated from a copy of a single cell from the parent organism. Natural clones, also known as identical twins, occur in humans and other mammals. These twins are produced when a fertilized egg splits, creating two or more embryos that carry almost identical DNA.

Reproduction of Malarial parasite:
The malarial parasite, Plasmodium, reproduces through a process called multiple fission. Multiple fission is a form of asexual reproduction where a single organism divides into multiple offspring.
Here is a detailed explanation of how the malarial parasite reproduces:
1. Multiple fission:
- The reproductive cycle of the malarial parasite begins when an infected mosquito bites a human, injecting the parasite into the bloodstream.
- The parasite then invades the liver cells and undergoes multiple rounds of division.
- During multiple fission, the parasite's nucleus undergoes multiple divisions without cytokinesis (cell division), resulting in the formation of multiple daughter nuclei within a single cell.
- Eventually, each daughter nucleus becomes surrounded by cytoplasm, forming individual daughter cells called merozoites.
- The liver cell ruptures, releasing the merozoites into the bloodstream.
2. Invasion of red blood cells:
- The released merozoites invade red blood cells, where they continue their reproductive cycle.
- Inside the red blood cells, the merozoites develop into trophozoites, which grow and multiply.
- The trophozoites then undergo multiple rounds of division through multiple fission, producing more merozoites.
3. Release and reinfection:
- The infected red blood cells eventually burst, releasing the newly formed merozoites into the bloodstream.
- These merozoites can then invade other red blood cells and repeat the reproductive cycle.
- Some merozoites differentiate into male and female gametocytes, which can be taken up by mosquitoes during a blood meal, completing the parasite's life cycle.
In conclusion, the malarial parasite reproduces through multiple fission, a process in which it undergoes multiple rounds of division to produce daughter cells called merozoites. This reproductive strategy allows the parasite to rapidly multiply and spread throughout the body, causing the symptoms of malaria.

The outgrowth of Hydra is termed as:
Bud:
- The outgrowth of Hydra is called a bud.
- A bud is a small, undeveloped hydra that grows out from the body of the parent hydra.
- It is a form of asexual reproduction in Hydra.
- The bud starts as a small bump on the body of the hydra and gradually grows in size.
- As the bud develops, it forms tentacles and a mouth, becoming an independent hydra.
- The bud eventually detaches from the parent hydra and lives on its own.
Other options explained:
Bulb:
- A bulb is a rounded underground storage organ present in some plants, such as onions or tulips.
- It is not related to the outgrowth of Hydra.
Daughter Hydra:
- A daughter hydra refers to a hydra that is produced through sexual reproduction.
- It is not the term used for the outgrowth of Hydra.
Tentacles:
- Tentacles are long, slender, flexible appendages found in Hydra.
- They are used for capturing prey and bringing it to the mouth of the hydra.
- While tentacles are present in Hydra, they are not specifically the outgrowth of Hydra.
Therefore, the correct term for the outgrowth of Hydra is a bud.

Asexual reproduction takes place by the process of budding in yeast.
The process of budding is a form of asexual reproduction where a new organism develops as an outgrowth or bud from the parent organism. Here is a detailed explanation of why yeast is the correct answer:
1. Yeast:
- Yeast is a unicellular organism belonging to the fungi kingdom.
- It reproduces asexually through a process called budding.
- Budding in yeast involves the formation of a small bud or outgrowth on the parent cell.
- The bud grows in size and eventually detaches from the parent cell, becoming a new individual.
- This process allows yeast to rapidly increase their population in favorable conditions.
- The new individuals produced by budding are genetically identical to the parent cell.
2. Plasmodium:
- Plasmodium is a parasitic protozoan that causes malaria.
- It reproduces asexually by multiple fission or schizogony, where the nucleus divides multiple times and forms multiple daughter cells.
- Budding is not a characteristic method of reproduction in Plasmodium.
3. Amoeba:
- Amoeba is a unicellular organism belonging to the protozoa group.
- It reproduces asexually by binary fission, where the parent cell divides into two daughter cells.
- Budding is not a characteristic method of reproduction in Amoeba.
4. Rhizopus:
- Rhizopus is a filamentous fungus commonly known as bread mold.
- It reproduces asexually by producing spores through a process called sporangiospores.
- Budding is not a characteristic method of reproduction in Rhizopus.
Therefore, the correct answer is C: Yeast. Yeast reproduces asexually through the process of budding.