CBSE Class 10 Biology How Do Organisms Reproduce Worksheet Set C

How do the Organisms Reproduce Notes Class 10 Science

Reproduction is the biological process by which new individual organisms –"offspring" -  are produced from their "parent" or parents.

Types of Reproduction:-
1. Asexual Reproduction – In this type, offspring that are genetically identical to a single parent.
2. Sexual reproduction- In this type, two parents contributes genetic information to produce an offspring.

DIFFERENT METHODS OF ASEXUAL REPRODUCTION

1. FISSION: the parent cell divides/splits into two daughter cell-Binary Fission; splits into many cells-multiple Fission.

5. VEGETATIVE PROPAGATION: A mode of reproduction in which part like the stem, root, leaves develop into new plant under favorable conditions.

Benefits
1. Plants can bear flowers, fruits earlier than those produced from seeds
2. Growing Banana, orange, rose, jasmine that have lost the capacity to produce seeds.
3. Genetical similarity is maintained in the plants.
eg. Sugarcane, rose, grapes by layering or grafting.

SEXUAL REPRODUCTION
When reproduction takes place as a result of fusion between two gametes, one from each parent, it is called sexual reproduction.
– This process of fusion between two gametes is called fertilization.
– The formation of gametes involves exchange of chromosomal (genetic) fragments between homologous chromosomes causing genetic recombination which leads to variation.

SEXUAL REPRODUCTION IN PLANTS

REPRODUCTION IN HUMAN BEING
Humans use a Sexual Mode of reproduction. It needs sexual maturation which includes creation of the germ cells ie, egg (ova) in the female and sperm in the male partner & this period of sexual maturation is called Puberty. Human beings have a well developed male and female reproductive system.

MALE REPRODUCTIVE SYSTEM
– The formation of male germ cell (sperms) takes place in the testes.
– A pair of testes are located inside scrotum situated outside the abdominal cavity. It is meant to keep relatively a low temperature needed for the production of sperms by testes.
– Testes release a male sex hormone called testosterone whose function is to:
1. Regulate the production of sperm
2. Brings about changes in appearance seen in boys at the time of puberty.
The secretion of prostate gland and seminal vesicle produce the fluid that nourishes and transports sperm (seminal fluid).

FEMALE REPRODUCTIVE SYSTEM
-The female germ cells or eggs are made in the ovaries, a pair of which is located in both side of abdomen.
-At the puberty, some of these Eggs start maturing. One egg is produced every month by one of the ovaries.
-Fertilization occurs in the fallopian tube of female genital tract.
-The fertilized egg also called zygote (2n) gets implanted in the lining of the Uterus, and start dividing. Actually uterus is richly supplied with blood to nourish the growing embryo. If zygote is not formed, the inner wall of uterus breaks which causes bleeding through vagina. This process is called MENSTRUATION.
-The Embryo gets nutrition from the mother's blood with the help of a special tissue called PLACENTA. It provides a large surface area for glucose and oxygen to pass from the mother to the embryo. Similarly the wastes from developing embryo are removed to mother's blood through placenta.

REPRODUCTIVE HEALTH
Reproductive Health means a total well-being in all aspects of reproductive, ie., physical emotional, social and behavioral.
Contraception: It is the avoidance of pregnancy. It can be achieve by Methods of contraception.

PHYSICAL BARRIER:-
1.Use of condoms, Diaphragm & cervical caps.
2.Copper-T or loop is placed in uterus to prevent pregnancy.

CHEMICAL METHOD:-
Oral contraceptive(OCs) - changes the hormonal balance to check the egg release in females. OCs cause side effect.

SURGICAL METHOD:-
1.Vasectomy, the vas deferens of male is blocked to prevent sperm transfer.
2.Tubectomy, the fallopian tube of female is blocked to prevent egg to reach uterus

SEXUALLY TRANSMITTED DISEASE(STDs) – These are the infectious diseases transmitted through sexual
contact .AIDS ,Gonorrhea, syphilis, genital herpes, warts are few commonly STDs.

More Important Questions For How Do Organisms Reproduce

Question. In rhizopus tubular structure bearing sporangia at their tips are called __________.
(a) Filaments
(b) Rhizoids
(c) roots
(d) Hyphae
Answer : D

Question. Cloning is a mode of :
(a) sexual reproduction
(b) asexual reproduction
(c) both a and b
(d) none
Answer : B

Question. The main cause of variations among organisms during sexual reproduction is
(a) Errors in copying DNA
(b) Errors in RNA
(c) Errors in both RNA and DNA
(d) Genetic drift
Answer : A

Question. Vegetative propagation refers to formation of new plants from———-.
(a) stem, roots, flowers
(b) stem, roots, leaves
(c) stem, flowers, fruit
(d) stem, leaves, flowers
Answer : B

Question. Priya was writing some statements; help her to choose the correct one. m:
(a) The existing organisms are called parent and the new organisms produced by them are called offspring.
(b) The production of new organisms from a single parent without the involvement of sex cells or gametes is called sexual reproduction.
(c) The production of a new organism from two parents by making use of their sex cells or gametes is called asexual reproduction.
(d) All the above
Answer : A

Question. The copying of DNA occur during
(a) cell formation
(b) cell division
(c) protein synthesis
(d) reproduction
Answer : B

Question. The reproduction is essential for population of a species
(a) to decrease its number
(b) to increase its number
(c) for its survival
(d) to become extinct
Answer : B

Question. In the last year board examination Rahul was asked a question where he had to choose the statement which was /were incorrect. Will you be able to answer the questionnswer This Question?
(a) In vegetative propagation, new plants are obtained from the parts of old plants without the help of any reproductive organs.
(b) It is necessary to plant the whole potato tuber in the ground to produce the new potato plants.
(c) Bryophyllum plants can be reproduced by vegetative reproduction by using either a piece of its stem or its leaves.
(d) The green grass grows in the fields after range from the dry, old stems of grass plants present in the fields, by the method of vegetative propagation.
Answer : B

Question. Plants like banana, rose ,jasmine ,orange have lost the capacity to produce
(a) Seeds
(b) Buds
(c) Flowers
(d) Roots
Answer : A

Question. Explain Binary Fission in Amoeba and Multiple fission in Plasmodium.
Answer : In the process of fission, a unicellular organism splits to form two or more new organisms. It is of two types.
(a) Binary fission: -In binary fission, the parent organism splits to form two new organisms.
Examples-Amoeba, Paramecium, Leishmania etc
(b) Multiple Fission: -In multiple fission the parent organism splits to form many new organisms at same time.
Example-Plasmodium

Question. In a flower, the parts that produce male and female gametes are——–
(a) stamen and anther
(b) Filament and stigma
(c) Anther and ovary
(d) stamen and style
Answer : (c) Anther and ovary

Question. Hydra reproduces————-by—————
(a) sexually, budding
(b) sexually, regeneration
(c) asexually, budding
(d) asexually, regeneration
Answer : (c) asexually, budding

Question. Reproduction is one of the most important characteristics of living beings. Give three reasons in support of the statement.
Answer : (i) For continuation of species
(ii) It promotes diversity in characters
(iii) Enhance the survival chances

Question. Which of these is not a part of male reproductive system?
(a) Scrotum
(b) Oviduct
(c) Vas-deferens
(d) Prostrate gland
Answer : B

Question. (a) Draw a neat diagram of female reproductive system of human being and label the following
(i) Parts where eggs are formed
(ii) Site of fertilization
(iii) Place of implantation
(iv) Place for entry of sperm
(b) What is contraception? List three advantages of adopting contraceptive measures.
Answer : (a)

(b) Contraception is the methods or ways to prevent fertilization and pregnancy in fertile females.
Three major advantages of adopting contraceptive measures are as follows:
(i) Help in family planning and population control.
(ii) Prevention of sexually transmitted diseases like gonorrhea, HIV-AIDS etc.
(iii) Prevention of unwanted pregnancies.

Assertion-Reason Type Questions
For question numbers 1 and 2 two statements are given-one labeled as Assertion (A) and the other labeled
Reason (R). Select the correct answer to these questions from the codes (a), (b), (c) and (d) as given below:
(a) Both ‘A’ and ‘R’ are true and ‘R’ is correct explanation of the assertion.
(b) Both ‘A’ and ‘R’ are true but ‘R’ is not correct explanation of the assertion.
(c) ‘A’ is true but ‘R’ is false.
(d) ‘A’ is false but ‘R’ is true.

Question. Assertion: DNA is deoxyribonucleic acid.
Reason: DNA transfers genetic characteristics from parents to offsprings.
Answer : B

Question. Assertion: There are three types of RNA, t-RNA, m-RNA and r-RNA.
Reason: RNA does not undergo replication.
Answer : B

Class 10 Science How Do Organisms Reproduce Notes and Questions

Objective type Questions

Question. The process of release of eggs from the ovary is called
a) Menstruation
b) Reproduction
c) Ovulation
d) Insemination
Answer : C

Question. Which among the following diseases is not sexually transmitted?
(a) Syphyllis
(b) Hepatitis
(c) HIV-AIDS
(d) Gonorrhea
Answer : B

Question. In case the ova does not fertilise which of the following events will take place?
a) Menstruation
b) Pregnancy
c) Implantation
d) ovulation
Answer : A

Question: At the time of entering into ovule, pollen tube has
a) three male nuclei
b) two mole nuclei
c) one gamete nucleus
d) four male gametes
Answer: Two male nuclei

Question: Which of the following is an IUCD?
a) copper – T
b) diaphragm
c) oral pills
d) tubectomy
Answer: copper – T

Question: Which of the following is not a part of female reproductive system in human beings?
(a) Ovary
(b) Uterus
(c) Vas deferens
(d) Fallopian tube
Answer: Vas deferens

Very Short Answer Question 

Question: Name the unicellular organism which caused the disease known as kala-azar. 
Answer: Leishmania 

Question: Which process taking place in the nucleus of a cell leads to variation in the offspring during reproduction? 
Answer: DNA copying 

Question: The simple animals such as planaria can be cut into number of pieces and each piece grows into a complex organism. What is this process known as? 
Answer: Regeneration 

Question: How may male gametes are produced by pollen grains? 
Answer: Two 

Question: Define parthenogenesis.
Answer: Development of organism from an unfertilized egg. 

Question: Which type of layering is done in Jasmine?
Answer: Air Layering (Gootee) 

Question: What is syngamy?
Answer: Fusion of male gamete with the egg cell is called syngamy. 

Question: Name the causative organism, of AIDS?
Answer: HIV – Human Immunodeficiency virus. 

Question: Where does fertilization takes place in human female?
Answer: Oviduct (fallopian tube)

Question: What is parturition?
Answer: Parturition – The birth of fully developed foetus in completion of gestation.

Question: How many follicles mature every month during the reproductive phase of human female?
Answer: One egg is produced every month by one of the ovaries

Question. Where is DNA found in the cell?
Answer: DNA is found in the nucleus

Question. Organisms have a varied body design. Name the property which gives the basic difference in body design.
Answer: Errors in DNA copying

Question. Name the life process of an organism which helps in the growth of its population.
Answer: Reproduction

Short Answer Question 

Question. List the advantages of vegetative propagation.
Answer : The advantages of vegetative propagation are as follows
• It helps in the easy propagation of non–flowering plants.
• It helps in producing hybrids of various plants, with improved qualities.
• It helps in the propagation of a large number of populations in a very short duration.
• It helps in the propagation of plants that do not produce seeds or produce them in very small quantities

Question. Explain various steps of budding in yeast.
Answer : Budding is a form of asexual reproduction usually observed in yeast.
• During this process, a small protrusion appears on the upper portion of the body of the organism. This bulge is called a bud.
• The bud gradually grows in size and forms an individual cell.
• From this newly budded cell, another bud appears at the tip.
• This process continues and a chain of c) Role in evolution – some variations is produced in the new organisms during reproduction which play an important role in evolution. yeast cells is obtained.

Question. What is the importance of reproduction?
Answer : Importance of reproduction – Maintenance of the existence – Organisms are maintaining their existence on the earth since their origin, million year ago, only because of reproduction. b) Preservation of species – Species (a group of similar organisms) are preserved because of reproduction. It is possible because reproducing organisms produce new individuals which are very similar to themselves.

Question. Why is variation beneficial to the species but not necessary for the individual?
Answer : Accumulation of variations after several generations results in new set of traits required for survival. As they show results after many generations so they are not important for individual.

Question. Can you think of reasons why more complex organisms cannot give rise to new individuals through regeneration?
Answer : More complex organisms cannot give rise to new individuals because:
1. Their body design is highly complicated.
2. There are specific organs to do specific functions.
3. There is a labour division in the body of complex organisms.
4. Exception is lizard, which can regenerate its tail.

Question. What are the changes seen in girls at the time of puberty?
Answer : At the time of puberty, breast size begins to increase, with darkening of the skin of the nipples. Also, girls begin to menstruate at around this time.

Question. Why is DNA copying an essential part of the process of reproduction?
Answer : DNA copying is needed because information stored in DNA is used to make protein. Synthesis of different proteins will lead to altered body design. Thus, reproduction at its most basic level involves making copies of the blueprints of body design.

Question. How will an organism be benefited if it reproduces through spores?
Answer : During adverse circumstances spore remain coated with protective layer. This helps an organism survive adverse conditions. Spores are means to tide over bad phases.

Question. What is the role of seminal vesicles and prostate gland?
Answer : Seminal vesicles are a pair of thin-walled muscular and elongated sacs which secrete a fluid for nourishment of sperms.
Prostate glands also produce a fluid which is released in the urethra along with secretion of seminal vesicle. It affects the vaginal pH so that sperms move smoothly inside the vagina.

Question. How does the embryo get nourished inside the mother’s body?
Answer : The embryo grows inside the mother's womb and gets nourishment from its mother’s blood through placenta. Placenta contains villi which connects the embryo with the mother’s blood. These villi provides a large surface area for glucose and oxygen to pass from mother to the embryo.

Question. If a woman is using copper-T, will it help in protecting her from sexually transmitted diseases?
Answer : No, it will not protect the woman from sexually transmitted diseases as fluid to fluid contact occurs in the vagina.

Question. How does reproduction help in providing stability to the population of species?
Answer : Stability is provided by equalizing the birth and death ratio. Thus, the rate of birth should approximately be equal to the rate of death.

Question. How is the process of pollination different from fertilization?
Answer : Pollination is the transfer of pollen grains from the anther of a stamen to the stigma of a carpel. These are transferred by agents such as insects, birds, wind or water.
Fertilization is defined as the fusion of a male gamete (sperm) with a female gamete (ovary) to form a zygote by sexual reproduction.

Question. What is the importance of DNA copying in reproduction?
Answer : DNA copying is an important phenomenon of reproduction through which the organisms pass on their characteristics to their offspring. It maintains the characteristics in different generations of the species. It also produces variations which are useful for the survival of species for long time.

Question. Name the information source of making proteins in the cell. State two basic events in reproduction.
Answer: DNA in the nucleus of a cell is the source of information for making proteins. The two basic events in reproduction are:
(i) creation of copy of DNA
(ii) creation of an additional cellular apparatus by cell then the DNA copies separate, each with its own cellular apparatus.

Question. The mode of reproduction depends on which feature of the organism?
Answer: The mode of reproduction depends upon the body design of organism. Those with simple body design may reproduce asexually. Those with complex body design may form gametes and may undergo sexual reproduction.

Question. What is DNA?
Answer: DNA means deoxyribo nucleic acid. It lies in the cell nucleus, which is the source of information for
making proteins and different proteins lead to different body designs.

Question. What is the effect of DNA copying which is not perfectly accurate in the reproduction process?
Answer: DNA copying will lead to variation in populations which helps in evolution of the species.

Question. Explain how do organisms create an exact copy of themselves.
Answer: The cell uses biochemical reactions to make exact copies of DNA or genetic material

CASE STUDY BASED QUESTION

Read the following and answer the questions:

Preeti is very fond of gardening. She has different flowering plants in her garden. One day few naughty children entered her garden and plucked many leaves of Bryophyllum plant and threw them here and there in the garden. After few days, Preeti observed that new Bryophyllum plants were coming out from the leaves which fell on the ground.

Question. What does the incidence sited in the paragraph indicate?
(a) Bryophyllum leaves have special buds that germinate to give rise to new plant.
(b) Bryophyllum an propagate vegetatively through leaves.
(c) Bryophyllum is a flowering plant that reproduces only asexually
(d) Both (a) and (b).
Answer : D

Question. Which of the following plants can propagate vegetatively through leaves like Bryophyllum?
(a) Guava
(b) Begonia
(c) Ginger
(d) Mint
Answer : B

Question. Do you think any other vegetative part of Bryophyllum can help in propagation? If yes, then which part?
(a) Roots
(b) Stems
(c) Flowers
(d) Fruits
Answer : B

Question. Which of the following plant is artificially propagated (vegetatively) by stem cuttings in horticultural practices?
(a). Potato
(b) Snake plant
(c) Rose
(d) Water hyacinth
Answer : C

CASE STUDY BASED QUESTIONS

The growing size of the human population is a cause of concern for all people. The rate of birth and death in a given population will determine its size. Reproduction is the process by which organisms increase their population. The process of sexual maturation for reproduction is gradual and takes place while general body growth is still going on. Some degree of sexual maturation does not necessarily mean that the mind or body is ready for sexual acts or for having and bringing up children. Various contraceptive devices are being used by human beings to control the size of population.

Question. What are common signs of sexual maturation in boys
a) Broadening of shoulders
b) Development of mammary glands
c) Broadening of waist
d) High pitch of voice
Answer : A

Question. Common sign of sexual maturation in girls is
a) Low pitch voice
b) Appearance of moustaches and beard
c) Development of mammary glands
d) Broadening of shoulders
Answer : C

Question. Which contraceptive method changes the hormonal balance of the body
a) Condoms
b) Diaphragms
c) Oral pills
d) Both a) and b)
Answer : C

Question. What should be maintained for healthy society
a) Rate of birth and death rate
b) Male and female sex ratio
c) Child sex ratio
d) None of these
Answer : B

ASSERTION REASON QUESTIONS:

Question. Assertion -Ovary releases one every month.
Reason-the lining of the uterus is always thick and spongy.
Answer : A is true but R is false.

Question. Assertion- Surgical methods are most effective methods of contraception.
Reason-Surgical methods block gametes transport and hence prevent fertilization.
Answer : Option A is correct

SEXUAL REPRODUCTION IN FLOWERING PLANTS

MCQ

Question. The transfer of pollen from the anther to stigma is called………………….
(a) Fusion
(b) fertilization
(c) Pollination
(d) Vegetative propagation
Answer : C

Question. Along the path of the vas-deferens the secretions of which gland provide nutrition to the sperms?
(a) Prostate glands
(b) Seminal vesicles
(c) Scrotum
(d) Urinary bladder
Answer : A

Question. Fruits are formed from
a. Stamen
b. Stigma
c. Ovary
d. Ovule
Answer : C

Question. Which of the following is the correct sequence of events of sexual reproduction in a flower?
а) pollination, fertilisation, seedling, embryo
(b) seedling, embryo, fertilisation, pollination
(c) pollination, fertilisation, embryo, seedling
(d) embryo, seedling, pollination, fertilisation
Answer : A

Question. Length of pollen tube depends on the distance between
(a) pollen grain and upper surface of stigma
(b) pollen grain on upper surface of stigma and ovule
(c) pollen grain in anther and upper surface of stigma
(d) upper surface of stigma and lower part of style
Answer : B

DESCRIPTIVE QUESTIONS

Question. Name the male and female gametes in animals. What is fertilization and where does it take place in human females ?
Answer : Male Gamete: Sperm (= spermatozoan) Female Gamete: Ovum.
Fertilization: It is the fusion of two compatible gametes (e.g., sperm and ovum) to form diploid zygote during sexual reproduction.
In human females fertilization occurs in fallopian tube

Question. Surgical methods can be used to create a block in the reproductive system for contraceptive purposes. Name such parts where blocks are created in
(a) Males and Females.
(b) State any two reasons for using contraceptive devices.
Answer : (a)Vasa deferentia and Fallopian tubes.
(b) -Contraceptive devices are used to prevent pregnancy for
-Limiting size of family by spacing birth of children
-Avoiding unwanted pregnancy.

Question. Prenatal sex determination has been prohibited by law. State two reasons.
Answer : The test has been banned since due to desire of male child, there has been large scale female foeticide. This has resulted in declining female-male sex ratio.

Question. What is placenta? State its two roles during pregnancy.
Answer : Placenta is a spongy vascular structure formed by the joint activity of maternal and foetal tissues in the wall of uterus that connects foetus with uterus.
Roles: Providing nutrition to the foetus. Taking away wastes of the foetus.

Question. (a) Name the parts 1 to 5 of human female reproductive system.
(b) Name the part in which fertilization takes place in the system

(b) Fallopian tube.
Answer : (a) 1 - fallopian tube,2— ovary,3 — Uterus, 4 — cervix, 5 — vagina.

What are the different patterns of fission that take place in unicellular organisms?
1) How do we know that two individuals belong to the same species?
2) What are the modes by which various organisms reproduce depend on?
3) What is advantage of growing plants asexually by the technique of tissue culture?
4) The sexual mode of reproduction incorporates the process of combining DNA from two different individuals. How is the problem of doubling of chromosomes overcome?
5) What is the importance of pollination?
6) How do ovaries function both, as the reproductive organs as well as the endocrine glands?
7) Which method is for removal of unwanted pregnancies?
8) After the cell division, why are surviving cells similar to, but subtly different from each other?
9) Why do multicellular organisms need to use more complex ways of reproduction?