How do organism reproduce class 10 Important Questions
Very Short Answer type
Question 1
List two functions performed by the testis in human beings? Answer
The testis in human beings serves a dual function: the production of sperm cells for reproduction and the secretion of testosterone for the development of male characteristics. These functions are vital for the reproductive capability of males and the manifestation of male traits.
Question 2
Name two unisexual flowers? Answer
Papaya and watermelon are the plants whose flowers are unisexual.
Question 3
What results in the re-establishment of the number of chromosome and the DNA content in the new generation? Answer
This occurs through Meiosis and Fertlization.Meiosis is a type of cell division that occurs in the reproductive cells of an organisms to form gametes which have half of the chromosomes and half the DNA of the parent. During fertilization these male and female gametes fuse to form the zygote, the DNA is restored to the normal complement and thus the chromosome number is maintained over generations.
Question 4
List two functions of ovary of human female reproductive system? Answer
The ovary in the human female reproductive system serves two primary functions:
Production of Ova (Egg Cells): The ovaries produce and release mature ova or egg cells during the menstrual cycle. This process, known as ovulation, is essential for sexual reproduction, as the egg cell is the female gamete that can be fertilized by a male sperm cell.
Secretion of Hormones: The ovaries secrete female sex hormones, primarily estrogen and progesterone. Estrogen is involved in the development of secondary sexual characteristics and regulates the menstrual cycle. Progesterone prepares the uterus for pregnancy by thickening the uterine lining, supporting embryo implantation if fertilization occurs.
Together, these functions contribute to fertility and the overall regulation of the female reproductive system.
Question 5
Where is DNA found in the cell? Answer
DNA is present in the nucleus of the eukaryotic cell
Question 6
Name two simple organisms having the ability of regeneration? Answer
hydra and planaria.
Question 7
Name the causative agent of the disease 'Kala-azar' and its mode of asexual reproduction? Answer
Leishmania. Its mode of asexual reproduction is known as binary fission.
Question 8
Name the floral parts of a plant that develop into (i) Fruit (ii) Seeds? Answer
Ovary and Ovule
Question 9
Name any two sexually transmitted diseases what advice is given to prevent them? Answer
syphilis and AIDS.
Advice to prevent them :
(i) Use of condoms.
(ii) Do not share injection needles / syringe.
Question 10
What is menopause? Answer
Menopause is a natural biological process in women, marking the end of menstrual cycles. It typically occurs between the ages of 45 and 55 and is defined by the absence of menstrual periods for 12 consecutive months. Menopause signifies the end of the reproductive phase, as the ovaries cease to release eggs and produce significantly lower levels of estrogen and progesterone. This hormonal change can lead to various symptoms such as hot flashes, night sweats, mood changes, and a decrease in bone density. Menopause is a normal part of aging and does not indicate any health problem or disease.
Question 11
Name one sexually transmitted disease each caused due to bacterial infection and viral infection. How can these be prevented? Answer
Gonorrhea from bacterial infection
Genital herpes from viral infection
This can be prevented by
(i) Use of condoms.
(ii) Avoiding multiple partner
Question 12
Name the parts where the germ cells of a flower are located? Answer
Stamens and Carpels
Question 13
Name the parts of bisexual flower that are not directly involved in reproduction Answer
sepals.
Question 14
Give one example for each of the following –
(i) Plants in which vegetative propagation occurs by grafting.
(ii) Plants in which vegetative propagation occurs by leaves? Answer
(i) Rose
(ii) Bryophyllum
Short Answer type
Question 1
Define the term double – fertilization?
Question 2
Why testes are located outside the abdominal cavity in a sac called scrotum?
Question 3
Mention the function of stamen?
Question 4
What is the role of seminal vesicle and the prostate gland?
Question 5
Write two differences between binary fission and multiple fission in a tabular form? Answer
Question 6
Draw a labeled diagram to show the different stages of binary fission in Amoeba? Answer
Question 7
Explain giving one example of each the unisexual and the bisexual flowers?
Question 8
How do Plasmodium and Leishmania reproduce? Write one difference in their mode of reproduction? Answer
Leishmania reproduces by binary fission in the host's macrophages. The organism divides into two identical daughter cells.
Plasmodium reproduces asexually by multiple fission within the liver cells and red blood cells. This process is known as schizogony, where a single organism divides into multiple daughter cells.
The main difference between their mode of reproduction is that in plasmodium , a single individual is divided into many daughter cells whereas in leishmania a single celled organism is divided into two daughter cells.
Question 9
Can you consider cell division as a type of reproduction in unicellular organism? Explain using one example? Answer
Yes, because it results in the formation of two daughter cells,that is, it results in the production of more individuals of the organism
Question 10
Give two suitable differences between radicle and plumula?
Question 11
What are the changes seen n girls at the time of puberty?
Question 12
Rajesh observed a patch of greenish black powdery mass on a stale piece of bread.
a. Name the organism responsible for this and its specific mode of asexual reproduction.
b. Name its vegetative and reproductive parts Answer
a.The greenish black powdery mass on a stale piece of bread is due to bread mould Rhizopus which reproduces by spore formation
b. Hyphae or thread like structures are the vegetative part and tiny blob like structures or sporangia are the reproductive parts
Question 13
a.Trace the path a male gamete takes to fertilise a female gamete after being released from the penis.
b. State the number of sets of chromosomes present in a zygote Answer
Male gamete (sperm) travels in the female reproductive tract after being released.
The path which it takes to fertilise the female gamete (egg) is vagina ,uterus, fallopian tube resulting in a zygote
Zygote has 2 sets of chromosomes / alternatively accept 2n. No marks to be assigned for n or 3n.
Question 14
State the post-fertilisation changes that lead to fruit formation in plants. Answer
After fertilisation, the zygote divides several times to form an embryo within the ovule.
The ovule develops a tough coat and is gradually converted into a seed.
The ovary grows rapidly and ripens to form a fruit.
The petals, sepals, stamens, style and stigma may shrivel and fall off.
Question 15
Why do multicellular organisms use complex way of reproduction? Answer
Multicellular organisms cannot reproduce by cell because they are not simple random collection of cells. In them, specialized cells are organized as tissues which are organized into organs. Cell-by-cell division would be impractical. Multicellular organisms, therefore, require to use more complex ways of reproduction.
Question 16
During reproduction inheritance of different proteins will lead to altered body designs Answer
The DNA in the cell nucleus is the information source for making proteins. If the information is changed, different proteins will be made. Different proteins will eventually lead to altered body designs. Therefore, a basic event in reproduction is the creation of a DNA copy.
Question 17.
What are the advantages of sexual reproduction over asexual reproduction? Answer
Sexual reproduction promotes genetic diversity, allowing for better adaptation to environmental changes, while asexual reproduction leads to identical offspring, limiting genetic variation.
Question 18.
In a bisexual flower, inspite of young stamens being removed artificially, the flower produces fruit. Provide a suitable explanation for the above situation? Answer
The pistil is intact. Cross pollination has occurred leading to fertilisation and formation of fruit
Question 19.
What changes are observed in the uterus if fertilization does not occur? Answer
The thick and spongy lining of the uterus slowly breaks and comes out through the vagina as blood and mucus
Long Answer type
Question 1.
In what respect is the human male gamete different from the female gamete?
Question 2.
Given below are certain situations. Analyze and describe its possible impact on a person:
a) Testes of a male boy are not able to descend into scrotum during his embryonic development.
b) Vas deferens of a man is plugged.
c) Prostate and seminal vesicles are not functional.
d) Egg is not fertilised in a human female.
e) Placenta does not attach to the uterus optimally. Answer
a) Sperm formation will be adversely affected because it requires a lower temperature than the body temperature.
b) Vas deferens is a passage for transfer of sperms, so sperms will not be transferred further.
c) When prostate and seminal vesicles are not functional, they will not add secretions for nourishment and medium for the transport of sperms.
d) When an egg is not fertilised in a human female, it lives for about one day. Then, the thickened lining of the uterus breaks leading to discharge of blood and mucus along with the unfertilised egg. This is called menstruation.
e) Nutrition and oxygen will not be provided to the growing embryo affecting its growth, which could have serious implications as well.
Question 3.
How does the embryo get nourishment inside the mother’s body?
Question 4.
How does reproduction help in providing stability to populations of species?
Question 6.
What is added to the sperm along the path of vas deferens ? Describe in brief?
Question 7.
In a bisexual flower, inspite of young stamens being removed artificially, the flower produces fruit. Provide a suitable explanation for the above situation?
Question 8.
Explain how is the DNA content maintained during the process of reproduction?
Question 9.
What is meant by menstruation? Why does it take place? How long does this process last?
Question 10.
What will happen when testosterone is released in the male reproductive system?
Question 11.
(a) Explain the term:-
(i)Implantation
(ii)Placenta
(b) What is the average duration of human pregnancy?
Question 12.
Explain vegetative propagation with the help of two examples? List two advantages of vegetative propagation?
Question 13.
What is meant by the term puberty? Give an example of the changes seen during puberty?
Question 14.
What are chromosomes? Explain how is sexually reproducing organisms the number of chromosomes in the pregnancy is maintained?
Question 15.
Distinguish between a gamete and a zygote? Explain their role in sexual reproduction?
Question 16.
How will an organism be benefited if it reproduces through spores? Answer
The reproduction by spores take place in plants. Spores are covered by hard protective coat which enables them to survive under unfavorable conditions, like lack of food, lack of water and extreme temperature but when the conditions are favorable the spores can grow to produce new plants. Thus, the reproduction by spores benefits the plant because by surviving under adverse conditions, the spores make these plants live forever.
Question 17.
What is the importance of DNA copying in reproduction? Question 18.
Which species is likely to have better chance of survival – the one reproducing asexually or the one reproducing sexually? Justify your answer. Question 19.
Why is variation beneficial to the species but not necessarily for the individual? Question 20.
Explain the process of regeneration in Planaria? How is his process different from reproduction? Answer
Planaria (Flatworm) is found in freshwater ponds. If the body of planaria somehow gets cut into number of pieces then each body piece can regenerate into complete planaria.
it occurs by the process of growth and development. The cells of cut body part divide rapidly to make ball of cells. The cells present in ball of cells move to their proper places and form various organs and body parts of an organisms.
The primary goal of regeneration is to repair and replace lost or damaged body parts. It is a response to injury or damage.while Reproduction is the process by which organisms create new individuals of the same species, either through sexual or asexual means.
Question 21.
What is AIDS? Which microbe is responsible for AIDS infection? State one mode of transmission of this disease. Explain in brief one measure for the prevention of AIDS.
Question 22.
(a) Draw a diagram of human female reproductive system and label the part –
(i)that produce egg
(ii)where fusion of egg and sperm takes place.
(iii)where zygote is implanted
(b) What happen to human egg when it is not fertilized?
Question 23.
Answer the following:-
(i)Name any four asexual mode of reproduction?
(ii)Explain with diagram the method by which an Amoeba reproduces?
(iii)How is fission different from fragmentation?
Question 24.
What are the different methods of contraception?
Question 25.
(a) Write the name of those parts of a flower which serve the same function as the following do in animals –
(i)Testes
(ii)Sperm
(iii)Ovary
(iv)Egg
(b) State the function of flower in the flowering part?
(c) Draw a labelled diagram of flower?
Question 25.
Trace the changes that take place in a flower from gamete formation to fruit formation Answer
Stamen is the male reproductive part and it produces pollen grains.
The ovary contains ovules and each ovule has an egg cell.
The pollen needs to be transferred from the stamen to the stigma.
If this transfer of pollen occurs in the same flower, it is referred to as self-pollination./ On the other hand, if the pollen is transferred from one flower to another, it is known as cross-pollination.
After the pollen lands on a suitable stigma, it has to reach the female germ-cells which are in the ovary. For this, a tube grows out of the pollen grain and travels through the style to reach the ovary/Figure
The male germ-cell produced by pollen grain fuses with the female gamete present in the ovule.
This fusion of the germ-cells or fertilisation gives the zygote.
After fertilisation, the zygote divides several times to form an embryo within the ovule.
The ovule develops a tough coat and is gradually converted into a seed. The ovary grows rapidly and ripens to form a fruit.
Meanwhile, the petals, sepals, stamens, style and stigma may shrivel and fall off.
Question 26.
(i) Describe the role of prostate gland, seminal vesicle and testes in the human male reproductive system.
(ii) How is the surgical removal of unwanted pregnancies misused?
(iii) Explain the role of oral contraceptive pills in preventing conception. Answer
(i) Prostate glands and seminal vesicle : add their secretions so that the sperms are in a fluid and it makes their transport easier and also provides nutrition.Testes secrete testosterone which brings about
changes in the appearances in the boys at the time of puberty.
(ii) Female foeticides/illegal sex selected abortion of female foeticide.
(iii) Interfere in release of egg and eggs are not release
Question 27.
All the reproductive methods of living organisms are broadly categorized into two types : 1. Asexual reproduction, and 2. Sexual reproduction. Asexual reproduction involves the participation of a single parent without the formation of gametes, fertilisation and transfer of genetic material. This method is a common means of rapidly increasing offsprings under favourable conditions.
(a) Name the type of fission that occurs in Leishmania and Plasmodium
(b) Write one advantage of sexual mode of reproduction over asexual reproduction.
(c) Give reasons why :
(i) Colonies of yeast fail to multiply in water but multiply in sugar solution.
(ii) Rhizopus individuals do not grow on a dry slice of bread.
(a) Binary fission and Multiple fission
(c) (i) Sugar provides energy for sustaining all life activities in yeasts. In water, it fails to reproduce because of inadequate energy in its cells.
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