NCERT Solutions for Class 10 Science Chapter 7 How do Organisms Reproduce?

Access NCERT Solutions Class 10 Science Chapter 7 How do Organisms Reproduce? (Intext Exercise)

Here are the step-by-step solutions to all the exercise questions that help in revising the concepts. Students can use the NCERT Solutions Class 10 Science Chapter 7 How do Organisms Reproduce?

Topic 7.1 Do organisms create exact copies of themselves

Q1. What is the importance of DNA copying in reproduction?

Answer:

The importance of DNA replication in reproduction is as follows:

1. It allows offspring to inherit traits from their parents.

2. It helps keep the species' characteristics the same over time.

3. Small errors during DNA copying lead to variations within a species, which are important for adaptation and evolution.

Q2. Why is variation beneficial to the species but not necessarily to the individual?

Answer:

Variation is useful to a species as it allows some individuals to adapt to changes in their environment, which helps the survival of the species. As an example, if there were an outbreak of disease, those with genetic resistance would be able to survive and reproduce. Variation, though, is not always profitable to an individual, as certain differences could make survival more difficult for some organisms.

Topic 7.2 - Modes of Reproduction Used by Single Organisms

Q1. How does binary fission differ from multiple fission?

Answer:

The difference between binary fission and multiple fission is given below:

Q2. How will an organism benefit if it reproduces through spores?

Answer:

Spore reproduction is a successful mode of survival and spreading in unfavorable conditions.

• Spores can resist extreme conditions because of the thick covering walls.

• They spread conveniently over distances, enabling the organism to grow in new areas.

Q3. Can you think of reasons why more complex organisms cannot give rise to new individuals through regeneration?

Answer:

Regeneration is common in simpler organisms but is limited in complex organisms because of their body structure.

• Complex organisms have specialized cells and tissues that make regeneration difficult.

• Simpler organisms with less specialised systems can regenerate whole individuals more easily.

Q4. Why is vegetative propagation practised for growing some types of plants?

Answer:

Vegetative propagation is a method of asexual reproduction used in plant cultivation of desirable traits on an economic scale.

• It guarantees rapid growth and retains the traits of the parent plant.

• It can be used for crops that have improved yield or disease resistance.

Q5. Why is DNA copying an essential part of the process of reproduction?

Answer:

DNA replication ensures the passing on of genetic information during reproduction for species continuity and adjustment.

• It makes children inherit traits from their parents, making species characteristics consistent.

• Mutations in DNA replication help species adapt and evolve in changing environments.

Topic 7.3 - Sexual reproduction

Q1. How is the process of pollination different from fertilisation?

Answer:

Fertilisation and pollination are the two most important processes of plant reproduction. Pollination is the movement of pollen, whereas fertilisation is gamete fusion.

• Pollination: Movement of the pollen grains from the male element (anther) to the female element (stigma) of a flower.

• Fertilisation: Male and female gamete fusion, resulting in the formation of a zygote, which is a process after pollination.

Q2. What is the role of the seminal vesicles and the prostate gland?

Answer:

The prostate gland and seminal vesicles are significant in male reproduction due to their role in secreting fluids that support and carry sperm.

• Seminal Vesicles: Secrete a fructose-rich fluid that gives energy to sperm and aids in semen development.

• Prostate Gland: Produces a fluid that assists in sperm protection and stimulation and adds to semen volume.

Q3. What are the changes seen in girls at the time of puberty?

Answer:

Puberty results in various physical and emotional modifications in women as they grow into adults.

• Breast development and broader hips.

• Menstruation occurs, marking the onset of reproductive ability.

Q4. How does the embryo get nourishment inside the mother’s body?

Answer:

The embryo is supported by the placenta, which links it to the mother's bloodstream.

• The placenta enables the passage of nutrients and oxygen from the mother to the embryo and the evacuation of waste materials.

• It sustains the growth of the embryo during pregnancy.

Q5. If a woman is using a copper-T, will it help in protecting her from sexually transmitted diseases?

Answer:

A copper-T is an intrauterine device (IUD) for contraception, but it does not offer protection against sexually transmitted diseases (STDs).

• It works by making the environment not conducive to sperm, but it does not close off infection.

• Further protection, like condoms, is required to minimise the risk of STDs.

Get NCERT Solutions Class 10 Science Chapter 7 How do Organisms Reproduce? (Chapter-End Exercise)

Q1. Asexual reproduction takes place through budding in

(a) amoeba.
(b) yeast.
(c) plasmodium.
(d) leishmania.

Answer:

Budding is a form of asexual reproduction where a new organism develops from a part of the parent.

The correct answer is Option (b) Yeast.

Q2. Which of the following is not a part of the female reproductive system in human beings?

(a) Ovary
(b) Uterus
(c) Vas deferens
(d) Fallopian tube

Answer:

Understanding the components of the female reproductive system is essential for biology.

The correct answer is Option (c) Vas deferens.

Q3. The anther contains

(a) sepals.
(b) ovules.
(c) pistil.
(d) pollen grains.

Answer:

The anther is an important part of the flower involved in reproduction.

The correct answer is Option (d) Pollen grains.

Q4. What are the advantages of sexual reproduction over asexual reproduction?

Answer:

Sexual reproduction produces variation due to the mixing of genes from two parents. This variation helps species adapt and survive in changing environments. It also reduces the chances of genetic diseases being passed on directly.

Q5. What are the functions performed by the testis in human beings?

Answer:

The testes have important functions in male reproductive health and function.

• They produce sperm cells required for reproduction.

• They secrete hormones, mainly testosterone, which control male characteristics and reproductive functions.

Q6. Why does menstruation occur?

Answer:

Menstruation is a natural phenomenon that occurs in women as part of the reproductive cycle.

• It occurs when the uterine lining is shed if there is no fertilisation after ovulation.

• The cycle readies the body for a possible pregnancy every month.

Q7. Draw a labelled diagram of the longitudinal section of a flower.

Answer:

A labelled diagram of a flower typically includes various parts such as petals, sepals, stamens, and pistils.

Labelled diagram of the longitudinal section of a flower

Q8. What are the different methods of contraception?

Answer:

Methods of contraception prevent pregnancy and can be very diverse in method.

• Barrier methods (such as condoms), hormonal methods (such as the pill), and intrauterine devices (IUDs) are a few examples.

• Natural methods involve monitoring ovulation and avoiding sex during fertile times.

Q9. How are the modes of reproduction different in unicellular and multicellular organisms?

Answer:

Difference between the mode of reproduction in a unicellular and a multicellular organism-

Q10. How does reproduction help in providing stability to populations of species?

Answer:

Reproduction is required to sustain healthy species populations over the long term.

• It allows for population growth, which ensures species can survive environmental changes.

• Reproduction also allows for genetic diversity, enhancing adaptability and resistance to disease.

Q11. What could be the reasons for adopting contraceptive methods?

Answer:

Individuals use contraceptive methods for different personal and health-related reasons.

• To avoid unwanted pregnancies and control family size based on individual situations.

• To control health problems or prevent pregnancy risks at certain stages or conditions of life.

Approach to Solve How do Organisms Reproduce? Class 10 Question Answer

Begin with careful reading of the chapter to understand the fundamental concepts of reproduction, both asexual and sexual.

• First, read the chapter slowly to understand the basics of reproduction, both asexual and sexual.

• Focus more on processes like binary fission, budding, and vegetative propagation.

• Understand how reproduction happens in plants and humans. Know the parts involved and what each part does.

• Learn the differences between various methods of reproduction simply. Make short notes from Chapter 7 How do Organisms Reproduce? question answer.

• Go through the NCERT Solutions for Class 10 properly and practice diagrams.

Also, check the NCERT Books and NCERT Syllabus here:

• NCERT Books Class 10 Science

• NCERT Syllabus Class 10 Science

• NCERT Books Class 10

• NCERT Syllabus Class 10

Main Topics of NCERT Class 10 Chapter 7 How do Organisms Reproduce?

The chapter is divided into several important topics and subtopics. The most important topics are given below. To gain clarity on these topics, students should refer to the NCERT Solutions for Class 10 Science Chapter 7 How do Organisms Reproduce?

1. Introduction to Reproduction

• Role of reproduction for the survival of a species
• Distinctions between asexual and sexual reproduction

2. Asexual Reproduction

• Binary Fission (Occurs in amoeba and bacteria)

• Budding (Occurs in Hydra and yeast)

• Vegetative Propagation (Occurs in plants such as potatoes and Bryophyllum)

• Fragmentation & Spore Formation (Techniques employed by algae and fungi)

3. Sexual Reproduction

• Description of gametes and fertilisation

• Sexual reproduction in flowering plants (pollination, fertilisation, seed formation)

• Reproductive system in humans (male and female reproductive organs)

4. Reproductive Health

• Need for reproductive health.

• Contraceptive methods and population control

Important Questions from Class 10 Chapter 7 How do Organisms Reproduce?

Given below is a question from the chapter, along with the detailed solution. Practicing different forms of questions improves confidence. All types of questions are included in the NCERT Solutions for Class 10 Science Chapter 7 How do Organisms Reproduce?

Question 1: Embryo receives the nutrition for growth from:

Options

1. Uterine wall

2. Ovary

3. Placenta

4. None of the above

Answer: An embryo receives its nutrients from the mother through a special tissue called the placenta. The placenta is a temporary organ that develops during pregnancy and connects the embryo to the mother’s uterus. It not only supplies nutrients and oxygen but also removes waste products from the embryo’s blood.

Hence, the correct answer is option (3), Placenta.

Question 2: How does the uterus change to attach the fertilized egg to its wall?

Options

1. The uterine wall becomes thin

2. The uterine wall becomes thick

3. The uterine wall does not change

4. None of the above

Answer: After fertilization, the uterine wall thickens due to increased blood supply and tissue growth. This helps in providing a suitable environment for the fertilized egg to attach and develop into an embryo. The thickened wall also nourishes the developing embryo.

Hence, the correct answer is option (2). The uterine wall becomes thick.

Question 3: Fertilization of male and female germ cells takes place in:

Options

1. Ovary

2. Fallopian tube

3. Uterus

4. Vagina

Answer:

Hence, the correct answer is option (2). Fallopian Tube.

What Students Learn from How do Organisms Reproduce? NCERT Solutions

Reproduction is an important process that helps living beings continue their species. This chapter explains how different organisms reproduce in simple ways.

• Modes of asexual reproduction, like fission, budding, and spore formation, are explained in the How do Organisms Reproduce? Class 10 questions and answers.

• Students learn the importance of sexual reproduction and how it creates variations.

• The basic structure and function of the human reproductive system are also covered.

• Students explore how fertilisation and embryo development take place in the body.

• How do Organisms Reproduce? Class 10 questions and answers also explain the importance of reproductive health.

NCERT Solutions for Class 10 Science

Below are the solutions for all the chapters included in the Class 10 Science. These solutions cover important questions and answers from each chapter.