How Do Organisms Reproduce, Class 10th Notes

THESE NOTES ARE PREPARED ACCORDING TO JKBOSE SYLLABI IN SIMPLIFIED AND CONCISE  PATTERN

Unit Summary: 

Reproduction (Def: The process by which living organisms produce young ones of their own kind)	Types: Asexual and Sexual I. Asexual: Single parent involved, No gametes II. Sexual: Two parents involved Steps: Sperm + Egg -> Zygote -> Embryo -> Foetus
Asexual Reproduction	Types: Binary Fission > Multiple Fission > Budding > Fragmentation > Spore Formation > Vegetative Propagation
Vegetative Propagation (Def: Production of new plants from vegetative parts of the plant)	Methods: Grafting e.g. Apples Cutting:  e.g. Rose Layering: e.g. Strawberry Tubers: e.g. Potatoes Bulbs:  Tulips, Onions Leaves: e.g Bryophyllum Tissue Culture: e.g. All plants
Structure of Flower	Flower is the reproductive part of the plant. It can be Unisexual or Bisexual. Parts: Sepals (Calyx) > Petals (Corolla) > Stamins (Androecium) > Carpel (Gynaecium)
Pollination (Def: Transfer of Pollen from Stamen to Pistil of same or another flower)	Types: Self Pollination & Cross Pollination Cross Pollination is carried by Pollinating agents such as Insects, Birds, Wind, Water, Animals, Humans etc
Male Reproductive System	Parts: Scrotum > Testes > Vasa Efferentia > Epididymis > Vasa Deferens > Urethra > Penis Glands: Seminal Vesicles > Prostate gland > Cowper gland
Female Reproductive System	Parts: Ovaries > Fallopian tubes (Oviduct) > Uterus > Vagina
Fertilization (Discovered by Antony Leevonhoek)	Def:  Fusion of male and female gametes to form Zygote Types: External (Fishes, Amphibians) Internal (Birds, Mammals)
Menstrual Cycle	Def: 28-day cycle which starts with Ovulation and ends with shedding of uterus lining Steps: I. Follicular Phase   II. Luteal Phase    III. Menstrual Phase
Contraception	Def: The methods of preventing sperm from meeting egg. Methods: Natural > Barrier > Oral > Surgical implants > Vasectomy > Tubectomy

Long answer questions

Q. Define reproduction? What are different types of reproduction?

Ans: Reproduction is process by which living organisms produce young ones of their own kind.

Reproduction is of two types;

I. Asexual reproduction: In this type of reproduction only one parent is involved in formation of new individual.

There is no formation of gamates.

II. Sexual reproduction: In this type of reproduction two parents are involved in formation of new individuals.

There is formation of gamates.




Q. What are the different types of asexual reproduction?

Ans:  Asexual reproduction is a type of reproduction in which only one parent is involved in formation of new individual.

There is no formation of gamates. It is of many types;

I. Binary fission: A single parent cell divides to form two daughter cells. E.g bacteria

II. Multiple fission: A single parent cell divides to form many daughter cells. E.g Plasmodium

III. Budding: A bud develops on the organism which grows in size and detaches when fully mature. E.g Hydra.

IV. Spore formation: The spores are formed in a sac like structure called sporangium which  are then released into air.

When the spores find suitable substratum, they develop into new individual. E.g Fungi.

V. Fragmentation: The thread like body gets divided into many fragments.
Each fragment develops into new individual.  E.g Algae.

VI. Vegetative propagation: It is most common in plants. In this type of reproduction, new plant is formed from vegetative parts such as stem, branch, root, tuber etc.

Vegetative propagation occurs by:
Grafting: E.g Apple
Cutting: E.g Rose
Layering: E.g Grasses
Tissue culture.

Q. List few advantages of Vegetative Propagation.

Ans: There are many advantages of vegetative propagation. They include:

I. Plants that do not have viable seeds can be reproduced.

II. Many plants can be grown from single plant.

III. Desirable characters of the plant can be mantained.

Q. Discuss the structure of Flower?
                                    Or
Write a note on reproductive part of plant.


Ans: The flower is reproductive part of plant. It has following parts.

I. Pedicel: It is the stalk of flower.

II. Thalamus: It is the broad base of pedicel.

III.  Calyx (Sepals), It is outer whorl of flower. It is usually green in colour.

IV. Corolla: (Petals), It is inner whorl of flower. It is colourful and scented.

V. Androecium: (Stamen), It is male reproductive part of flower. It has flament, anther and anther lobes. The pollen grains are found inside anther lobes.

VI. Gynaecium: (Carpel), It is female reproductive part of flower. It has stigma, style and ovary.




Q. Write a note on male reproductive system of human beings?

Ans: Reproduction is process by which living organisms produce young ones of their own kind.  Humans undergo sexual reproduction.

The male reproductive system consists of following parts:

I. Testes: The are made of seminiferous tubules and are located in scrotum. The testes produce sperm and male harmone testosterone.

II. Epididymes: It is tube like structure where sperms mature.

III. Vasa Differentia: It joins epididymes with seminal vesicles

IV. Vasa Efferentia: It helps is sperm transport.

V. Ejaculatory duct: It opens into urethra. The urethra carries both urine and sperm.

VI. Penis: It is male copulatory organ.

There mare many glands linked with male reproductive system e.g. Seminal vesicles, Prostate gland, Cowpars glands.





Q. Write a note on female reproductive system of human beings?

Ans: Reproduction is process by which living organisms produce young ones of their own kind.  Humans undergo sexual reproduction.

The female reproductive system consists of following parts:

I. Ovaries : The female have two ovaries. They produce egg.
They also produce harmones like estrogen, progestrone.

II. Fallopian tubes: They connect ovaries to uterus.

III. Uterus: It is pear shaped . Its lining is called endometrium and its lower part is cervix.
The foetus develops inside uterus.

IV. Vagina: It recieves penis during copulation and also serves as birth canal.




Q. What is Fertilization? What are different types of fertilization?

Ans: The fusion of male and female gamates to form zygote is called fertlization.

Fertilization is of two types;

I. External Fertilization: In this, the fusion of male and female gamate takes place outside the body of female. E.g Fishes, Amphibians.

II. Internal Fertilization: In this, the fusion of male and female gamates takes place inside the body of female. E.g Mammals, Birds.




Q. What is Pollination? What are its types?

Ans: The transfer of pollen grain from Stamen to Carpel of same or different flower is called pollination.

The Pollination is of two types,

I. Self Pollination: The transfer of pollen from stamen to carpel of same flower  or another flower on same plant is self pollination.

In this type, The pollinating agents are not required.

II. Cross Pollination: The transfer of pollen from stamen to carpel of another plant.

In this type, the pollinating agents are required e.g . Wind, Insects, Birds etc.

Q. How is the sex of the child determined in human beings ?

Ans: The sex of child is determined by sex chromosomes. Males have XY chromosomes where as Females have XX chromosomes.

If the sperm with X chromosome fertilizes egg, The child will be female.

If the sperm with Y chromosome fertilizes egg, The child will be Male

Important Textual Questions:


Q. What is the importance of DNA Copying in reproduction?

Ans: DNA copying mantains body design and perfection in different generations of a species.

Error in DNA copying can lead to abnormalities in the population.





Q. How does binary fission differ from multiple fission?

Ans:

Q. 

Q. How is process of Fertilization different from Pollination?

Ans:

Q. What is role of seminal vesicles and prostate gland?

Ans: The seminal vesicles secrete fructose and prostaglandins. They provide energy to sperm.

The Prostate gland secretions help in sperm motality.




Q. What are the advantages of Sexual reproduction over Asexual reproduction?

Ans: Sexual reproduction helps in new combination of genes. This helps organisms to adopt to changes in environment.



Q. What is the function performed by testes in humans?

Ans: The testes produce sperms and male sex harmone called testosterone.




Q. Why does mensuration occur?

Ans: The mensuration occurs in females to flush out unfertilized egg and broken endometrium.

It occurs after every 28 days.



Q. What are the different methods of contraception?

Ans: contraception means prevention of fusion of gamates.
The different methods of contraception are:

I. Natural: It can be done by avoiding intercourse from 10th to 17th day of mensuration cycle.

II. Barrier method: Use of barriers such as condom, copper T

III. Oral: Use of medicine which prevent fertlization.

IV. Surgical: It includes vasectomy and tubectomy.



Q. How does reproduction help in providing stablility to populations?

Ans: Reproduction helps species to increase their population.

It protects species from genetic drift.

It brings in useful variations to popluations.

It helps them to adopt to changing environment. 

Q. Why is vegetative propagation practiced for growing some types of plants?

Ans: Vegetative propagation is practiced because:
i. It is a quicker and less difficult way.
ii. It can aid plant growth in areas where germination has failed.
iii. It can be used to propagate plants that don't generate viable seeds or produce a small quantity of seeds.
iv. It's a quick way to grow a lot of plants in a short amount of time.
v. Potato tubers and ginger rhizomes are two examples.



Q. What is Puberty ? Name the hormones responsible for the production of secondary sexual characters in human beings?
Ans: Puberty is the age when an individual is getting mentally, physiologically and emotionally ready for reproduction. It is characterized by change in height, body shape, voice and development of sex organs.
Different hormones are responsible for production of secondary sexual characters in human beings, Such as:
Estrogen in females
Testosterone in males

Q. Chances of fertilization are more if copulation has taken place during the middle of menstrual cycle. Give reasons.

Ans: Fertilization is the process of fusion of sperm and egg to form zygote.

The chances of fertilization is more if copulation has taken place in the middle of menstrual cycle because the egg is present in the fallopian tube where the fertilization occurs.



Q. Give reasons for the following:

i. Petals of flowers are variously coloured

ii. Some plants are propagated only by vegetative methods.

Ans:
i. Petals of flowers are variously coloured

Petals of flowers are variously coloured in insect pollinated and bird pollinated flowers so that it can attract insects and birds from distances.

ii. Some plants are propagated only by vegetative methods.

Ans: Some plants are propagated only by vegetative methods such as through stem, root or leaf because they do not produce viable seeds.

E.g. Banana, Bryophyllum, Potato etc

 

Objective Type Questions :

Q. Asexual reproduction takes place through budding in:

a. Amoeba        b. Yeast
c. Plasmodium   d. Leshmania

Ans: b. Yeast

Q. Which of following is not part of female reproductive system?

A. Ovary       B. Uterus
C. Vasa deferens    D. Fallopian tubes

Ans:   C. Vasa deferens


Q. The anther contains,

a. Sepals     b. Ovules
c. Carpel     d. Pollen

Ans: d. Pollen


Q. Which of following are reproductive parts of flower?

A. Sepals      B. Petals     C. Stamins and Carpels

Ans: C. Stamins and Carpels

Q. The special tissue by which embryo gets nutrition through mothers blood is

A. Amnion     B. Chorion  
C. Placenta     D. Zygote


Ans: C. Placenta

Q. A small portion of vas deferens is removed in

A. Tubectomy    B. Vasectomy
C. IUCD              D. Barrier method

Ans: B. Vasectomy


Q. The portion of plant that is grafted on the other plant is called:

A. Stock        B. Scion        C. Graft     D. Stump

Ans: B. Scion

Q. Regeneration occurs in

A. Planaria     B. Spyrogyra
C. Hydra         D. All of above

Ans: D. All of above

Q. Yeast reproduces by

A. Binary fission      B. Budding
C. Fragmentation    D. Sexual reproduction

Ans: B. Budding



Q. Layering is used in

A. Rose     B. Jasmine
C. Mango   D. None of above

Ans:   B. Jasmine


Q. Fertilization occurs in:

A. Ovary                    B. Uterus
C. Fallopian tube    D. Vagina


Ans:  B. Uterus



Q. Spirogyra can reproduce by:

A. Fission       B. Vegetative propagation
C. Fragmentation      D. Regeneration


Ans: C. Fragmentation


Q. Multiple fission occurs in

A. Planaria      B. Paramecium
C. Hydra          D. Rhizopus


Ans:   B. Paramecium


Q. The germ cells are specialized for:
A. Vegetative propagation
B. Immunity
C. Asexual reproduction
D. Sexual reproduction


Ans: D. Sexual reproduction


Q. Reproductive parts of angiosperms are located in

A. Flowers         B. Roots
C. Shoots           D. Fruits


Ans: A. Flowers

Q. Name the plant harmone that inhibits growth.

Ans:  The plant harmonne which inhibits growth is Abscisic acid.


Q. Modes of asexual reproduction?

Ans: The different modes of Asexual reproduction are Binary fission, Multiple fission,Budding, Fragmentation, Spore formation and vegetative propagation.

Q. Function of placenta.
Ans: Placenta provides the food and oxygen to fetus. It also removes waste materials.

Q. What is the other name of sex cells?

Ans: The sex cells are also called gamates.

 Q. What are the female sex cells in humans called?

Ans: The female sex cells are called Eggs or Ova

Q. What are the male sex cells in humans called?

Ans: The male sex cells in humans are called sperms.

 Q. Assertion: Spores are unicellular bodies.

Reason: The parent body simply breaks up into smaller pieces on maturation

 Ans: A is correct and R is wrong

 Q. Assertion: The sex of a child is determined by the mother.

Reason: Humans have two types of chromosomes: XX and XY

 Ans: A is wrong and R is correct.

 

Q. The process where the unfertilized egg is released out of the body with blood is known as:

a. Mensuration b. Fertilization c. Germination d. Pollination

Ans: a. Mensuration



Q. The testes are located outside the abdominal cavity in scrotum because:

a. Sperm formation requires more space b. Sperm formation requires a lower temperature

c. Sperm formation requires a higher temperature d. Both A and C

Ans: b. Sperm formation requires a lower temperature



Q. Growing foetus derives nutrition from mother’s blood through:

a. Uterus b. Fallopian tube c. Placenta d. Cervix

Ans: c. Placenta

 

Q. Assertion: At puberty human male develops secondary sexual characters

Reason: There is decreased secretion of testosterone at puberty

A. Both A and R are true and R is the correct explanation of A

B. Both A and R are true and R is not the correct explanation of A

C. A is True, R is False

D. A is False, R is True

Ans: C. A is True, R is False



Q. Assertion: In human males, testes are extra abdominal and lie in scrotal sac

Reason: Scrotum keeps temperature lower by 2C for normal spermatogenesis

A. Both A and R are true and R is the correct explanation of A

B. Both A and R are true and R is not the correct explanation of A

C. A is True, R is False

D. A is False, R is True


Ans: A. Both A and R are true and R is the correct explanation of A



Q. Which of the following is the correct sequence regarding sexual reproduction in flowering plant?

a. Pollination, Fertilization, Seedling, Embryo

b. Seedling, Embryo, Fertilization, Pollination

c. Pollination, Fertilization, Embryo, Seedling

d. Embryo, Seedling, Pollination, Fertilization

Ans: c. Pollination, Fertilization, Embryo, Seedling



Q. After fertilization, which of the following parts develops into seed?

a. Ovary b. Ovule c. Pollen grain d. Stigma

Ans: b. Ovule



Q. Assertion: Vagina acts as copulation canal and fertilization canal

Reason: Both insemination and fusion of gametes occur in vagina

A. Both A and R are true and R is the correct explanation of A

B. Both A and R are true and R is not the correct explanation of A

C. A is True, R is False

D. A is False, R is True

Ans: C. A is True, R is False

Q. Assertion (A): Pollen grains from the carpel stick to the stigma of stamen.

Reason (R) : The fertilized egg cells grow inside the ovules and become seeds.

Ans: (D) A is false but R is true.

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