Q1: Why simply copying of DNA
in a dividing cells not enough to
maintain continuity of life?
Answer: Copying of DNA along
with creation of an additional
cellular apparatus is necessary.
Q2: How does plasmodium
undergo fission?
Answer: Plasmodium divides into
many daughter cells simultaneously
Q3: How spirogyra reproduces by fragmentation?
Answer: Breaks up into smaller pieces, on maturation
each fragment grows into new individual.
Q4: Which cells are responsible for budding in
Hydra?
Answer: Regenerative cells
Q5: On which plant can you find buds on its leaves?
Answer: Bryophyllum
Q6: Write the scientific name of the bread mould.
Answer: Rhizopus
Q7: Name the structure into which following
develops : the plumule and radicle?
Answer: plumule -> shoot. radicle -> root.
Q8: Where are the testes located in human beings?
Answer: Outside abdominal cavity in scrotum.
Q9: For what specific reason have the testes
specific location?
Answer: sperm formation requires lower temperature
2-3 degrees below than normal body temperature.
Q10: Correlate the rate of general body growth and
maturation of reproductive tissue during
puberty?
Answer: Body growth rate slows down while
reproductive tissues (organs) begin to mature.
Q11: Where does the zygote get implanted in
human beings ?
Answer: In wall of uterus
Q12: Which two important chemical substances are
delivered to developing embryo through
placenta?
Answer: Glucose and oxygen
Q13: Name the tissue in mother's body that
provides nutrition to developing embryo?
Answer: Placenta
Q14: How change in hormonal balance prevents
pregnancy?
Answer: It prevents the release of eggs.
Q15: Write one side effect of loop placed in uterus?
Answer: Causes irritation and excessive bleeding in
uterus.
Q16: Which structures need to be blocked in males
and females respectively to prevent pregnancy?
Answer: Vas deferens in male (vasectomy), fallopian
tube in female (tubectomy)
Q17: Write the ill effects of misuse of surgery?
Answer: Foeticide (killing girl child).
Q18: Why is children sex ratio alarmingly declining
in our country?
Answer: sex selective abortions
Q19: Name the chemical methods of preventing
pregnancy.
Answer: Oral pills
Q20: Name some of the devices used as mechanical
method for preventing pregnancy.
Answer: loop, copper T, condoms
Q21: Name the only mammal(s) which lays eggs?
Answer: Duck-billed platypus and echidna .
Q22: Define Parthenogenesis.
Answer: Parthenogenesis is a type of asexual
reproduction where the embryo development takes
places without fertilization. A few species of insects,
bees, wasps, birds and lizards (e.g. Komodo Dragon
lizard) reproduce this way.
Q23: Name the various types of asexual
reproduction
Answer: Various types of asexual reproduction are:
Budding,
Fission,
Spore formation,
Fragmentation,
Regeneration,
tissue culture
Q24: Give an example of an organism which
produces by fragmentation?
Answer: Spirogyra
Q25: What is the full form of AIDS?
Answer: Acquired Immune Deficiency Syndrome
Q26: Give examples of organism that reproduce by
spore formation.
Answer: Bacteria, Fungi (rhizopus) , moss, algae
Q27: Give examples of plants which reproduce by
stems.
Answer: Plants like potato (tuber), onion(bulb)
reproduce by vegetative propagation of stems.
Q28: What are various artificial vegetative
propagation techniques?
Answer: Various artificial vegetative propagation
techniques are:
cutting
layering
grafting
tissue culture
Q29: What is oospore?
Answer: A diploid zygote formed by the fusion of male
and female gamete is called oospore.
Q30: Give example of plants where self-pollination
is observed.
Answer: Pea and China rose
Q31: Give example of plants that do cross-
pollination.
Answer: Most of plants do cross-pollination e.g.
sunflower, tulip
Q32: What is allogamy?
Answer: Another name of cross-pollination.
Q33: Give examples of surgical methods to birth
control.
Answer: Tubectomy (females) and Vasectomy (males)
Q34 : What is parthenocarpy?
Name two fruits developed by this process.
Answer: It is development of fruit without fertilization.
Fruits are called virgin-fruits or seedless fruits.
Examples are watermelons, grapes etc.
Q35: Give examples of organisms which are
Hermaphrodites.
Answer: Earthworm, leech, starfish.
Hermaphrodites are bisexual organisms which possess
both male and female reproductive organs.
Q36: Give examples of unisexual animals.
Answer: Birds, Mammals etc.
Q37: What is syngamy?
Answer: The process of fusion of male gamete with
female gamete is called syngamy.
Q38 Write the full form of IUCD
Answer: IUCD stands for IntraUterine Contraceptive
Device - or Copper T - a mechanical barrier method
used in females for birth control.
Q39 What will happen when Planaria
gets cut into two pieces?
Answer: Each part of the Planaria grows into a new
organism. It is an example of asexual reproduction by
fragmentation.
Q40 Out of the following plants which
two plants are reproduced by vegetative
propagation?
jasmine, wheat, mustard,
banana
Answer: jasmine, banana
Q41: Give examples of plants which have unisexual
flowers
Answer: papaya, watermelon
Q42: Give examples of plants which have bisexual
flowers.
Answer: Hibiscus, mustard
Q43: If a woman is using copper-T will it help in
protecting her from sexual transmitted diseases?
Answer: No. copper-T will not protect the women from
STDs. It is a barrier method for birth control i.e. kill
sperms but do not kill STD causing microbes.
Q44: How does copper-T work?
Answer: Copper-T releases copper ions which mix with
uterine fluid. When this ions-rich fluid come in contact
with sperms, it kills these sperms and hence avoid
pregnancy.
Q45: What are the advantages of Autogamy or Self-
pollination?
Answer: Advantages of Self-pollination are:
1. It is a sure method of seed formation.
2. Scent and Nectar are not needed by the flower to
attract insects.
3. Parent characteristics are preserved in offsprings.
4. Small quantity of pollen is required for pollination.
5. Flowers need not be large or attractive.
Q46: What are the disadvantages of Self-
pollination?
Answer: Disadvantages are:
1. Plants loose their vigor in their future generations due
to repeated self-pollination.
2. Since there is no variation, no genetic improvement
occurs in offsprings.
3. Weak characters of the plant are inherited by the next
generations.
Q47: What is Allogamy?
Answer: Cross-pollination is known as allogamy. It is the
process of transfer of pollen from the anther of a flower
to stigma of a flower of another plant of the same
species or closely related species.
Q48: Define germination.
Answer: The seed contains the future plant or embryo
which develops into a seedling under appropriate
conditions. This process is known as germination.
Q49: What is grafting?
Answer: In grafting, one part of a plant is inserted into
another plant in a way that both of them will unite and
grow together as a single plant
.
Q50: What are different types of grafting
techniques?
Answer: Different methods of grafting are:
1. Approach grafting
2. Cleft grafting
3. Bud grafting
4. Tongue grafting
Hlp tkn cbse notes
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