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 23degrees 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: Duckbilled
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 selfpollination is observed.
Answer: Pea and China rose
Q31: Give example of plants that do crosspollination.
Answer: Most of plants do crosspollination e.g. sunflower, tulip
Q32: What is allogamy?
Answer: Another name of crosspollination.
Q33: Give examples of surgical methods to birth control.
Answer: Tubectomy (females) and Vasectomy (males)
Q34(CBSE old pattern): What is parthenocarpy?
Name two fruits developed by this process.
Answer: It is development of fruit without fertilization. Fruits are
called virginfruits 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(CBSE 2005): 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(CBSE 2011): 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(CBSE 2011): 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 copperT
will it help in protecting her from sexual
transmitted diseases?
Answer: No. copperT
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 copperT
work?
Answer: CopperT 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 Selfpollination?
Answer: Advantages of Selfpollination
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 Selfpollination?
Answer: Disadvantages are:
1.
Plants loose their vigor in their future generations due to repeated
selfpollination.
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:
Crosspollination 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
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