Monday, October 31, 2011

Class 10 - Biology - How Do Organisms Reproduce? (Very Short Questions & Answers)

 How Do Organisms Reproduce? 

Avocado Seed
credits:wpclipart


Very Short answer Questions asked in board examinations. 
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

AnswerVarious 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)


Parthenocarpy
Watermelon by Parthenocarpy
(credits:wikimedia)
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 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(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 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

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