How do Organisms Reproduce?
Very Short Q & A Based on CBSE Question Papers
Q1: Name the scientist who used the Latin phrase "Omnis cellula e cellula," means "Every Cell From a Cell"?
Answer: Rudolf Virchow, a German Scientist who emphasised that cell produces cells.
Q2: Does Cell Division play an important role in reproduction?
Answer: Yes. It plays important role in both prokaryotes and eukaryotes. It is important in following two ways:
i. gives rise to a new organism or daughter cell.
ii. in multicellular prokaryotes, cell division renews and repairs cells that die from wear and tear.
Q3: Give an example cell division occurs in human body for continuity of life?
Answer: Bone marrow continuously produce new blood cells.
Q4: What is the crucial function of cell division?
Answer: To pass genetic material (DNA copy) to offspring cellular apparatus.
Q5: What are the types of cell division? Give examples of each
Answer: There are two types of cell division:
i. Mitotis : This cell division occurs in most of the cells of the body. Parent cells divides into two (or more) offspring cells passing on identical copies of DNA (genetic material).
ii Meosis: This cell division occurs in cells of reproductive organs (called male and female gametes). Each offspring cell contains half copy of DNA material froms its parent cell. When these male and female gametes fuse together, it gives rise to new organism.
Q6: Is binary fission in bacteria mitotic or meosis cell division?
Answer: Mitotic cell division.
Q7: Is cell division a controlled process? If not what would happen?
Answer: Yes cell division is a controlled process in a cell cycle. For example any malfunction results in abnormality and may lead to cancer cells. Cancer cells reproduce with uncontrolled rate and gives tumors in the body.
Q8: Can we say asexual reproduction occurs due to mitosis cell division?
Q9: Can we say sexual or bisexual reproduction occurs due to meotic cell division?
Q10: Why do human offspring resemble their parents but they are not identical to them?
Answer: It is because the human offspring is the result of sexual reproduction i.e. it contains half of genetic material from each of its parent. Offspring is genetically varied from its parents.
Q11: Which forms the basis of evolution in life cycles of organisms?
Answer: Genetic variation.
Q12: Can genetic variation occur in asexual reproducing organisms?
Answer: Generally the offspring cells produced asexually are genetically identical. But due to external factors (e.g. environmental factors), genetic variation can occur. You might have heard that different variants of disease cause microbes are found.
Q13: What is cell differentiation?
Answer: Cell differentiation is the process by which cells having same genetic material become different from one another.
Q14: Is vegetative reproduction type of asexual reproduction?
Q15: Name the plants which give rise to new plants through spores.
Answer: Mushroom, Ferns and Mosses
Q16: How many chromosomes are there in a human cell?
Answer: 23 pairs or 46.
Q17: Define regeneration.
Answer: It is an ability of an organism to reproduce wholly from a part of another one.
Q18: Give two examples of animals that reproduce through regeneration.
Answer: Planaria and Hydra
Q19: Name the female reproductive part of a flower.
Answer: Carpel (consists of stigma, style and ovary)
Q20: Which part of the flower develops into a seed and fruit?
Answer: Ovule develops into a seed while ovary ripens to form a fruit.
Q21: Name the male hormone.
Q22: Name the female hormone.
Q23: What happens if Fallopian tube is blocked?
Answer: If Fallopian tube is blocked, the egg will not be able to reach the uterus. In such case fertilization will not take place.
Q24: Is fertilization possible without pollination?
Answer: No. Fertilization is followed by pollination.
Q25: In a bisexual flower inspite of young stamens being removed artificially, the flower produces fruit. Give reasons.
Answer: Removing stamens will prevent self-pollination. But cross pollination (pollen grains from stamens of other flower) will take place, thus flower bears fruit.
Q26: Name two surgical methods of birth control.
Answer: Vasectomy (removing small portion of vas deferns in males) and Tubectomy (removing small portion of Fallopian tube in female)
Q27: What is the role of prostate gland?
Answer: It adds alkaline secretion into the semen which are essential to sperm activity.