HOW DO ORGANISMS REPRODUCE: Short Answer Type Questions Class 10th Chapter 10 JKBOSE/NCERT
Short Answer Type Questions
Question 1. What is multiple fission? Give an example.
Ans: Multiple fission is a form of asexual reproduction in which a single organism divides into multiple daughter cells simultaneously. Each daughter cell becomes an individual organism. An example of multiple fission is seen in the protozoan parasite Plasmodium, which causes malaria. Plasmodium undergoes multiple fission within the host’s red blood cells, leading to the release of numerous daughter cells called merozoites.
Question 2. Name two unisexual and two bisexual flowers.
Ans: Two examples of unisexual flowers are:
Papaya: It has separate male and female flowers on different plants.
Watermelon: It also has separate male and female flowers on different plants.
Two examples of bisexual flowers are:
Rose: It has both male stamens and female pistils within the same flower.
Sunflower: It also has both male and female reproductive structures within the same flower.
Question 3. Name any four pollinating agencies.
Ans: Four examples of pollinating agencies are:
Bees: Bees collect nectar from flowers and inadvertently transfer pollen from one flower to another.
Wind: Some plants have light and abundant pollen grains that are carried by the wind to reach other flowers.
Butterflies: Butterflies are attracted to flowers and assist in pollination as they feed on nectar.
Birds: Certain bird species, such as hummingbirds, feed on flower nectar and aid in transferring pollen between flowers.
Question 4. Define placenta. Write its function.
Ans: Placenta is a specialized organ that develops in the uterus of mammals during pregnancy. It serves as a connection between the mother and the developing fetus, providing a means for nutrient and gas exchange. The placenta enables the transfer of oxygen and nutrients from the mother’s bloodstream to the developing fetus, while waste products from the fetus, such as carbon dioxide, are removed.
Question 5. Define regeneration. Explain with an example.
Ans: Regeneration is the ability of an organism to regrow or replace lost or damaged body parts. It involves the growth and development of new tissues and organs to restore the structure and function of the organism. An example of regeneration is observed in starfish. If a starfish loses one of its arms, it can regenerate a new arm in its place.
Question 6. How is variation beneficial to the species?
Ans: Variation is beneficial to a species for several reasons:
Adaptation: Variation provides a range of traits within a population, allowing individuals to possess characteristics that may be advantageous in different environments. This increases the chances of survival and successful reproduction in changing conditions.
Evolution: Variation is the raw material for natural selection and evolution. Through the process of natural selection, individuals with favourable variations are more likely to survive and pass on their genes to the next generation, leading to the accumulation of beneficial traits over time.
Disease Resistance: Variations in the genetic makeup of a population can provide resistance to diseases. If a population has diverse genetic traits, some individuals may possess natural resistance to certain diseases, reducing the overall impact of the disease on the population.
Species Resilience: Variation ensures the resilience and long-term survival of a species. In the face of environmental changes or threats, species with higher genetic diversity are more likely to have individuals with traits that can adapt and respond to new challenges, increasing the chances of survival and avoiding extinction.
Question 7. Write the differences between stamens and carpels.
1. Stamens are the male reproductive structures of a flower.
2. They consist of two main parts: the filament and the anther.
3. The filament is a slender stalk that supports the anther.
4. The anther contains pollen grains, which are the male gametes or sperm cells.
5. The stamens collectively form the androecium of a flower.
1. Carpels are the female reproductive structures of a flower.
2. They are also known as pistils.
3. A carpel consists of three main parts: the stigma, style, and ovary.
4. The stigma is the receptive surface that receives pollen.
5. The style is a slender tube that connects the stigma to the ovary.
6. The ovary contains ovules, which are the female gametes or egg cells.
7. The carpels collectively form the gynoecium of a flower.
Question 8. Write any two differences between the vas deferens and the fallopian tube.
Ans: Vas deferens
1. Vas deferens is part of the male reproductive system.
2. It is a long muscular tube that connects the epididymis to the ejaculatory duct.
3. Its main function is to transport mature sperm from the epididymis to the urethra.
4. It is involved in the passage of sperm during ejaculation.
1. The fallopian tube is part of the female reproductive system.
2. It is also known as the oviduct or uterine tube.
3. It connects the ovary to the uterus.
4. Its main function is to transport the released egg (ovum) from the ovary to the uterus.
5. It is the site of fertilization, where the sperm and egg meet.
Question 9. Write the differences between external and internal fertilization.
Ans: External Fertilization
1. External fertilization occurs outside the body of the organisms.
2. It is common in aquatic environments.
3. The release of eggs and sperm occurs in the external environment, usually in water.
4. The fertilization process happens externally, with sperm swimming to reach the eggs.
5. Examples include fish, frogs, and many aquatic invertebrates.
1. Internal fertilization occurs inside the body of the organisms.
2. It is common in terrestrial environments.
3. The sperm is deposited directly into the female reproductive system, typically through copulation.
4. Fertilization occurs within the female’s body, where the sperm and egg meet.
5. Examples include mammals, reptiles, birds, and some insects.
Question 10. Name the various organs of the female reproductive system.
Ans: Various organs of the female reproductive system:
1. Ovaries: The ovaries produce and release eggs (ovulation) and also produce female sex hormones.
2. Fallopian Tubes (Oviducts): The fallopian tubes transport eggs from the ovaries to the uterus and are the site of fertilization.
3. Uterus (Womb): The uterus is where a fertilized egg implants and develops into a fetus during pregnancy.
4. Cervix: The cervix is the lower part of the uterus that connects to the vagina.
5. Vagina: The vagina is a muscular canal that serves as the birth canal during childbirth and also receives the penis during sexual intercourse.
6. External Genitalia (Vulva): The external genitalia includes the labia, clitoris, and vaginal opening.
Question 11. Write the function of seminal vesicles and prostate gland.
Ans: Functions of seminal vesicles and prostate gland:
1. Seminal vesicles are accessory glands of the male reproductive system.
2. They secrete a fluid that contributes to the composition of semen.
3. The fluid contains fructose, which provides energy for sperm, and other substances that nourish and activate sperm.
4. The seminal vesicles’ secretions help in sperm motility and survival.
1. The prostate gland is walnut-sized in the male reproductive system.
2. It produces and secretes prostatic fluid, which is a component of semen.
3. The prostatic fluid contains enzymes, citric acid, and zinc, which help nourish and activate sperm.
4. It also helps in the neutralization of acidic conditions in the female reproductive tract, providing a more suitable environment for sperm survival.
Question 12. Write any two advantages of vegetative reproduction.
Ans: Advantages of vegetative reproduction:
1. Preserving Desirable Traits: Vegetative reproduction allows for the preservation of desirable traits and characteristics of a parent plant.
2. Rapid and Reliable Reproduction: Vegetative reproduction enables the rapid and reliable production of new plants without the reliance on seeds. This can be advantageous for plants that have low seed viability or that take a long time to produce viable seeds.
3. It allows for the propagation of exact genetic copies of the parent plant, ensuring consistency in desirable traits.