Class 10 · Science · Chapter 7: How do Organisms Reproduce?
Bihar Board · NCERT · CBSE
All 80 objective questions (MCQ) of this chapter — solve first, then tap “Show answer”. Each question shows its source label: «BSEB 2025 · board paper» = verified from the official board paper; «Board-style (practice)» = Study With Me's own practice questions.
← Chapter 7: How do Organisms Reproduce? — full notes, video, questions
Budding as asexual reproduction happens in which of these?
Correct answer: (B) Yeast
Yeast buds. Amoeba and Leishmania use binary fission. Plasmodium uses multiple fission.
Along with a copy of DNA, what else must be made in reproduction?
Correct answer: (B) New cellular equipment
Without new cellular equipment, a DNA copy pushed out cannot run life processes.
Which part of Rhizopus on bread is the reproductive part?
Correct answer: (B) Sporangium
The sporangium holds the spores. A hypha is not the reproductive part.
What is the plane of binary fission in Amoeba like?
Correct answer: (B) Any plane
Amoeba splits into two equal parts in any plane.
Binary fission in the parasite of kala-azar is —
Correct answer: (B) In a definite direction
The plane stays fixed because of the whip-like end.
Reproduction in Spirogyra is mainly —
Correct answer: (B) Fragmentation
A simple filament breaks into new Spirogyra. That is fragmentation.
The bud in Hydra is formed —
Correct answer: (B) By repeated division at one fixed place
Repeated division at one place forms a bud, which later separates.
Which piece of a potato makes a new plant?
Correct answer: (B) The one with an eye or a bud
The piece with a bud gives a shoot and roots.
Compared with plants from seed, plants from vegetative propagation —
Correct answer: (B) Can flower and fruit earlier
They can flower and fruit earlier and the characters stay like the parent.
Which piece of a money-plant gives a new leaf?
Correct answer: (B) The one with at least one leaf
The node with a leaf gives a new plant. The bare middle piece does not.
Where are pollen grains made?
Correct answer: (C) Anther
The anther of the stamen makes pollen.
A hibiscus flower is generally —
Correct answer: (B) Bisexual
Hibiscus and mustard have both stamens and a carpel.
Where does fertilisation occur in humans?
Correct answer: (B) Oviduct
Fertilisation occurs in the oviduct. The embryo later settles in the uterus.
Which is not a part of the female reproductive system?
Correct answer: (C) Vas deferens
The vas deferens is in the male system.
Self-pollination occurs in which of the following plants?
Correct answer: (B) Bisexual
In self-pollination pollen reaches the stigma of the same flower, so the flower must have both stamens and pistil — a bisexual flower such as hibiscus or mustard (lesson 7). It cannot happen in a unisexual flower like papaya.
In which part of the uterus does the embryo develop?
Correct answer: (A) Endometrium (inner lining)
The zygote divides to form an embryo, which is implanted in the thick, blood-rich inner lining of the uterus (endometrium) and grows there; the placenta also forms there (lesson 8).
Which of the following parts is found only in the male genitalia?
Correct answer: (D) Vas deferens
The vas deferens carries sperms from the testis towards the urethra — a part of the male reproductive system. The other three belong to the female system (lesson 8). This is also NCERT exercise Q2.
By which method does reproduction take place in Hydra?
Correct answer: (B) Budding
The book says Hydra forms a bud by repeated cell division at one specific site; the bud grows into a tiny Hydra and detaches — budding (lesson 4). Hydra can also regenerate, but binary fission is the method of Amoeba.
The male reproductive organ of a flower is the—
Correct answer: (A) Stamen
The stamen is the male part and makes pollen grains. The stigma is the tip of the pistil (female part); petals only attract (lesson 7).
Sperm is produced in the—
Correct answer: (D) Testis
Sperms are formed in the testes, which lie outside the abdominal cavity in the scrotum because sperm formation needs a temperature lower than the body temperature (lesson 8). Eggs are formed in the ovaries.
The basic event in reproduction is—
Correct answer: (D) creation of a DNA copy
Book: the basic event in reproduction is the creation of a DNA copy, along with additional cellular apparatus.
Variation during reproduction is useful for—
Correct answer: (A) the survival of the species
Book: variation is useful for the survival of species over time, not necessarily for the individual.
The causative organism of kala-azar is—
Correct answer: (B) Leishmania
Book: Leishmania causes kala-azar; its binary fission occurs in a definite plane.
The malarial parasite Plasmodium reproduces by—
Correct answer: (C) multiple fission
Book: Plasmodium divides into many daughter cells at once by multiple fission.
The usual mode of reproduction in Spirogyra is—
Correct answer: (D) fragmentation
Book: mature Spirogyra breaks into fragments, each growing into a new individual.
Forming a complete organism from cut pieces is seen in—
Correct answer: (D) Planaria
Book: Hydra and Planaria cut into pieces regenerate a complete organism from each piece.
In Bryophyllum new plants arise from—
Correct answer: (B) buds in the notches along the leaf margin
Book: buds produced in the notches along the leaf margin fall on the soil and grow into new plants.
In tissue culture the mass of cells formed first is the—
Correct answer: (B) callus
Book: cells from the growing tip divide in a nutrient medium to form a callus; hormones then make plantlets.
In Rhizopus spores are formed in the—
Correct answer: (D) sporangia
Book: the thread-like hyphae are not reproductive; spores form in the round sporangia.
The female reproductive part of a flower is the—
Correct answer: (A) pistil
Book: the pistil (stigma, style, ovary) is female; the stamen is male.
After fertilisation the ovary becomes the—
Correct answer: (B) fruit
Book: ovule → seed and ovary → fruit; sepals, petals, stamens and style shrivel and fall.
Why are the testes located outside the abdominal cavity?
Correct answer: (C) sperm formation needs a lower temperature than the body
Book: sperm formation requires a lower temperature than the normal body temperature, so the testes lie in the scrotum.
Where does fertilisation take place in humans?
Correct answer: (D) oviduct (fallopian tube)
Book: sperm travel upwards and meet the egg in the oviduct.
Which of these is a viral sexually transmitted disease?
Correct answer: (B) HIV-AIDS
Book: gonorrhoea and syphilis — bacterial; warts and HIV-AIDS — viral.
Asexual reproduction takes place through budding in—
Correct answer: (B) Yeast
Yeast reproduces by budding (Activity 7.1). Amoeba and Leishmania divide by binary fission, Plasmodium by multiple fission.
Which of the following is not a part of the female reproductive system in human beings?
Correct answer: (C) Vas deferens
The vas deferens belongs to the male system; the other three are parts of the female system.
The anther contains—
Correct answer: (D) pollen grains
The anther of the stamen contains the pollen grains.
Asexual reproduction by budding takes place in —
Correct answer: (B) Yeast
Yeast reproduces by budding.
This is not part of the female reproductive system —
Correct answer: (C) Vas deferens
The vas deferens is in the male system.
The anther contains —
Correct answer: (D) Pollen grains
The anther makes pollen grains.
The plane of binary fission in Amoeba —
Correct answer: (B) Can be any plane
Amoeba divides in any plane.
In humans fertilisation occurs in the —
Correct answer: (B) Oviduct
Fertilisation occurs in the oviduct.
A copper-T —
Correct answer: (B) Avoids pregnancy, not infection
A copper-T avoids pregnancy. It does not stop a sexually transmitted disease.
The embryo receives oxygen —
Correct answer: (B) Through the placenta
Oxygen and glucose pass across the large surface of the placenta.
An example of vegetative propagation is —
Correct answer: (B) Growing banana from a stem
Banana cannot make seeds, so it is grown by the vegetative method.
Reproduction in Spirogyra is —
Correct answer: (B) Fragmentation
Pieces of the simple filament become new organisms.
After fertilisation the fruit is formed from the —
Correct answer: (B) Ovary
The ovary becomes the fruit and the ovule the seed.
Binary fission in Leishmania —
Correct answer: (B) In a fixed direction
The structure at one end fixes the direction.
The root that grows first in a gram seed is the —
Correct answer: (B) Radicle
The radicle is the future root. The plumule is the future shoot.
A condom —
Correct answer: (B) Is a mechanical barrier and lowers infection risk to some extent
A condom stops sperm and lowers the risk of many infections to some extent.
The reproductive cell in Rhizopus is the —
Correct answer: (B) Spore
Spores are in the sporangium. A hypha is not the reproductive part.
The usual mode of reproduction in yeast is—
Correct answer: (D) budding
Small buds form on yeast cells (Activity 7.1).
Binary fission in Amoeba—
Correct answer: (A) can occur in any plane
Amoeba can split in any plane.
At one end of a Leishmania cell there is a—
Correct answer: (B) flagellum
A flagellum at one end, so it splits in a definite plane.
Malaria is caused by—
Correct answer: (D) Plasmodium
Plasmodium is the malarial parasite.
A bud in Hydra forms by—
Correct answer: (D) repeated cell division at one site
Repeated division at one site forms the outgrowth.
In potato vegetative propagation occurs by—
Correct answer: (B) eyes on the stem tuber
Potato is an underground stem; its eyes are buds.
Which piece of a money plant grows into a new plant?
Correct answer: (B) one with at least one node
A bud sits at the node; an internode piece does not grow (Activity 7.6).
Tissue culture is commonly used for—
Correct answer: (C) ornamental plants
Book: common for ornamental plants.
An organism that reproduces by spores is—
Correct answer: (D) Rhizopus
Rhizopus (bread mould) forms spores in sporangia.
The part of the stamen in which pollen grains form—
Correct answer: (A) anther
Pollen forms in the anther.
An ovule contains an—
Correct answer: (B) egg cell
Each ovule has an egg cell.
The pollen tube grows to reach the—
Correct answer: (C) ovule
It grows through the style to the ovule (Fig. 7.8).
The future shoot in a seed is the—
Correct answer: (D) plumule
Plumule = future shoot; radicle = future root.
Food in a seed is stored in the—
Correct answer: (A) cotyledons
Cotyledons store food (Fig. 7.9).
A zygote is formed by—
Correct answer: (B) fertilisation
Fusion of gametes = fertilisation → zygote.
The part that makes a sperm move is its—
Correct answer: (C) long tail
The long tail helps it swim.
Secretions of the seminal vesicles and prostate—
Correct answer: (D) nourish sperm and ease their movement
They provide nutrition in a fluid and ease movement.
A change at puberty in girls is—
Correct answer: (A) breast development and the start of menstruation
Girls: breast development, menstruation; boys: facial hair, voice.
The embryo implants in the—
Correct answer: (B) uterine wall
It implants in the thick lining of the uterus.
Normally each month an egg is released by—
Correct answer: (C) one ovary
One egg each month from one of the ovaries.
Menstruation usually lasts—
Correct answer: (D) 2 to 8 days
Book: about 2–8 days.
A method that lowers the risk of STDs is the—
Correct answer: (A) condom
A condom barrier also blocks germs.
Contraceptive pills work by—
Correct answer: (B) changing the hormonal balance so no egg is released
Pills change the hormonal balance.
Prenatal sex determination—
Correct answer: (C) is prohibited by law
Book: it is prohibited by law.
Variation improves the survival of—
Correct answer: (D) the species (population)
Variation helps the species survive a changed niche.
An example of fragmentation is —
Correct answer: (B) Spirogyra
Spirogyra reproduces by fragmentation.
One job of the testis is —
Correct answer: (B) Making sperms and testosterone
The testes make both sperms and testosterone.
A student placed four potato pieces on moist cotton. Two had an eye, two did not. After four days green shoots appeared —
Correct answer: (B) Only on the pieces with an eye
The eye itself is the bud. A piece without a bud does not grow.
A woman does not want a pregnancy and also wants to reduce infection. The more suitable choice is —
Correct answer: (B) A condom
A condom lowers the risk of both pregnancy and many infections. A copper-T does not stop infection.
← Chapter 7: How do Organisms Reproduce? — full notes, video, questions
