CHAPTER 7 How do Organisms Reproduce KSEEB SSLC CLASS 10 SCIENCE SOLUTIONS

CHAPTER 7-How do Organisms Reproduce KSEEB SSLC CLASS 10 SCIENCE SOLUTIONS , English medium Karnataka state board,the Answers Are Prepared By Our Teachers Which Are Simple ,Pointwise,Easy To Read And Remember .

CHAPTER 7-How do Organisms Reproduce?KSEEB SSLC CLASS 10 SCIENCE SOLUTIONS

What is the importance of DNA copying in reproduction?

. Importance of DNA copying in reproduction:

DNA copying is essential for passing on features from parents to the next generation.
It contains information as molecules, serving as blueprints for body designs.
DNA determines protein production, which, in turn, shapes body designs.
During reproduction, cells divide, each containing a copy of the DNA.
DNA copying ensures the transmission of genetic information.
Variation in DNA copying leads to subtle differences in offspring.

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

Importance of variation to the species but not necessarily for the individual:

Variation enhances species’ adaptability to changing environments.
Populations occupy specific niches, and variation aids adaptation.
Individuals with advantageous variations survive and reproduce better.
Genetic diversity increases the likelihood of adaptation to new conditions.
Drastic variations may not benefit individuals, but they are crucial for species survival and evolution.

How does binary fission differ from multiple fission?

Difference between Binary Fission and Multiple Fission:

Binary fission splits one organism into two equal parts, while multiple fission divides it into many daughter cells at once.
Binary fission is common in bacteria and Amoeba, whereas multiple fission occurs in Plasmodium.
Each daughter cell in binary fission gets a full set of genetic material, but in multiple fission, genetic material may differ.
Binary fission is mainly in unicellular organisms, while multiple fission can occur in both unicellular and multicellular organisms.

How will an organism be benefited if it reproduces through spores?

Benefits of Spore Reproduction for an Organism:

Spore formation creates resistant structures surviving harsh conditions.
Spores disperse easily over long distances, aiding habitat colonization.
Spores have protective walls ensuring survival until suitable growth conditions.
Spore reproduction leads to rapid multiplication, enhancing survival and reproduction.

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

Reasons for Complex Organisms Not Using Regeneration for Reproduction:

Complex structures make cell-by-cell division impractical for reproduction.
Regeneration may not always produce fully functional organisms.
Regeneration demands significant energy and resources.
Complex organisms evolved more efficient reproductive strategies like sexual reproduction.

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

Reasons for Practicing Vegetative Propagation in Plants:

Vegetative propagation produces genetically identical offspring, retaining desired traits.
It’s quicker and more reliable than seed propagation, especially for slow-maturing plants.
It bypasses juvenile growth stages, leading to earlier flowering and fruiting.
Vegetative propagation ensures the survival of sterile or seedless plants.

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

Importance of DNA Copying in Reproduction:

DNA replication accurately transmits genetic information.
It creates identical DNA copies passed to daughter cells during division.
DNA replication maintains genetic stability, preventing errors and mutations.
Accurate DNA copying ensures genetic diversity, facilitating adaptation to environments.

How is the process of pollination different from fertilisation?

Pollination: Transfer of pollen from stamen to stigma of the same or different flower.
Fertilisation: Fusion of male and female gametes (sperm and egg) to form a zygote.

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

Seminal Vesicles: Add fluid to sperm to aid in their movement and provide nutrients.
Prostate Gland: Secretes fluid that mixes with sperm to form semen, enhancing sperm motility and viability.

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

Breast development
Menstruation begins
Growth of pubic and underarm hair
Skin changes, such as acne
Development of hips and other secondary sexual characteristics.

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

Through the placenta, which connects the developing embryo to the mother’s uterine wall.
The placenta allows exchange of nutrients and oxygen from mother’s blood to the embryo, and removal of waste products from the embryo to the mother’s blood.

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

No, a copper-T (intrauterine device) is a contraceptive method that prevents pregnancy by blocking sperm from reaching the egg or by preventing implantation of a fertilised egg.
It does not protect against sexually transmitted diseases.

EXERCISES

Asexual reproduction takes place through budding in

(a) amoeba.

(b) yeast.

(c) plasmodium.

(d) leishmania.

(b) yeast.

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

The anther contains

(a) sepals.

(b) ovules.

(c) pistil.

(d) pollen grains.

(d) pollen grains.

What are the advantages of sexual reproduction over asexual reproduction?

Advantages of sexual reproduction over asexual reproduction:

Ensures genetic diversity.
Facilitates adaptation to changing environments.
Allows for the combination of beneficial traits.
Enhances resistance to diseases and parasites.
Promotes evolutionary innovation and speciation.
Increases the likelihood of species survival.
Supports ecosystem stability and resilience.

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

Functions performed by the testis in human beings:

Produces sperm cells (spermatogenesis)
Secretes hormones like testosterone
. Facilitates the development of secondary sexual characteristics in males.
. Regulates the male reproductive system.
. Supports sexual maturation during puberty.
. Maintains sperm production throughout adult life.
. Ensures fertility in males.

Why does menstruation occur?

Reason for menstruation:

Monthly shedding of the uterine lining.
Expulsion of unfertilized egg and uterine tissue.
Hormonal changes trigger the process.
Prepares the uterus for potential pregnancy.
Occurs in reproductive-age females.
Part of the menstrual cycle.
Lasts for several days.
Resets the reproductive system for the next cycle.
Commonly referred to as a period.

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

What are the different methods of contraception?

. Methods of contraception:

Barrier methods (condoms, diaphragms)
Hormonal methods (birth control pills, patches, injections)
Intrauterine devices (copper-T, hormonal IUDs)
Sterilization (vasectomy for males, tubal ligation for females)
Fertility awareness methods

How are the modes for reproduction different in unicellular and multicellular organisms?

Modes for reproduction in unicellular and multicellular organisms:

Unicellular Organisms:

Reproduce asexually through methods like binary fission, budding, or spore formation.
Lack specialized reproductive organs.
Offspring are genetically identical to the parent.
Rapid reproduction rate.
Suitable for stable environments with abundant resources.
Limited genetic variation.

Multicellular Organisms:

Reproduce sexually or asexually.
Have specialized reproductive organs.
Offspring exhibit genetic variation due to genetic recombination.
Reproduction rate generally slower than unicellular organisms.
Adapted for diverse environments.
Increased genetic diversity enhances survival in changing conditions.

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

How reproduction provides stability to populations of species:

Ensures species continuation.
Maintains genetic diversity.
Offspring inherit traits from both parents.
Increases variability within populations.
Allows natural selection to act.
Replenishes population losses.
Regulates ecosystem balance.
Transfers beneficial traits and behaviors.

What could be the reasons for adopting contraceptive methods?

Reasons for adopting contraceptive methods:

To control the timing and number of pregnancies.
To prevent unintended pregnancies.
To avoid the risks associated with childbirth and pregnancy complications.
To maintain or improve the health and well-being of the mother and child.
To enable individuals to pursue educational or career goals without the burden of early parenthood.
To promote family planning and spacing between pregnancies.
To address socio-economic factors such as poverty and overpopulation.
To prevent the transmission of sexually transmitted infections (STIs).
To empower individuals, especially women, with reproductive autonomy and decision-making.
To promote responsible and informed sexual behavior.
To contribute to sustainable population growth and environmental conservation.