BOARD EXAM IMP | Cha -1 | Reproduction In Organisms | 2 Questions & Answer

BOARD EXAM IMP | Cha -1 | Reproduction In Organisms | 2 Marks Questions & Answer 

1. Distinguish between asexual and sexual reproduction . Why is vegetative reproduction also considered as a type of asexual reproduction?

• Asexual Reproduction
• It is always uniparental .
• There is no formation and fusion of gametes .
• Only mitotic cell division takes place .
• Offsprings are genetically identical to the parents .
• Sexual Reproduction
• It is usually biparental 
• Formation and fusion of gametes take place .
• It involves both meiosis and mitosis .
• Offsprings genetically differ from the parents .

2. What is vegetative propagation ? Give two suitable examples .

• The process of multiplication , in which parts or fragments of the plant act as reproductive unit or propagule to form new individuals is called vegetative propagation .
• Examples : ( 1 ) Buds ( eyes ) of Potato ( ii ) Rhizome of Ginger

3. Define Juvenile phase 

• Juvenile phase : Before reacting sexual maturity all organisms have to undergo a proper phase of physical growth . This phase is called juvenile phase . In human the juvenile phase lasts up to 12 to 13 years of age

4. Define Reproductive phase

• Reproductive phase : Once reproductive system is mature enough to produce male and female gametes the organism is ready to mate and reproduce . This phase is called reproductive phase . Some major hormonal changes mark this phase . In human the reproductive phase starts at about 12 to 13 years and lasts up to 55 to 60 .

5. Identify each part in a flowering plant and write whether it is haploid ( n ) or diploid ( 2n ) .( a ) Ovary ( b ) Anther ( c ) Egg ( d ) Pollen ( e ) Male gamete  ( f ) Zygote

• ( a ) Ovary    -   diploid   
• ( b ) Anther  -   diploid
• ( c ) Egg         -   haploid
• ( d ) Pollen    -  haploid
• ( e ) Male gamete - haploid
• ( f ) Zygote  - diploid

6. Define external fertilization . Mention its disadvantages .

• In most aquatic organisms such as algae , fishes and amphibians , syngamy occurs outside the body of organism in the external medium ( water ) . This type of gametic fusion is called external fertilization .
• Disadvantage : Many of the offsprings are not protected from the predators and their survival is threatened upto adulthood .

7. Differentiate between gametogenesis and embryogenesis .

• Gametogenesis
• By this process , male and female gametes are formed.
• It involves meiosis .
• Embryogenesis
• It is the process of development of embryo from zygote .
• It involves mitosis .

8. Describe the post fertilization change in a flower .

• After fertilization the following changes occur in a flower
• Zygote is formed inside the ovule and develops into the embryo .
• The ovules develop into the seed .
• The ovary develops into the fruit .
• Ovary wall is transformed into a protective layer , pericarp .

9. What are gemmules ? Name the organism which produce gemmules . Make a labelled diagram of gemmule .

• Gemmules are internal buds formed inside the parent's body . Example : Fresh water sponges ( Spongilla ) .

10.Write the modes of asexual reproduction in the following organisms . Sycon , Penicillium , Spongilla , Paramecium , Yeast , Marchantia , Amoeba and Chlamydomonas .

• Organism              Modes of Reproduction
• Sycon                       External budding
• Penicillium             Conidia
• Spongilla                 Internal budding ( Gemmule ) 
• Paramecium           Binary fission ( transverse )
• Yeast                         Budding ( External )
• Marchantia             Gemmae
• Amoeba                   Binary fission ( Simple ) 
• Chlamydomonas    Zoospores

11. Draw the diagram of any fruit showing seed and pericarp

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GUJARAT BIOLOGY NEET

NEET MATERIAL IN GUJARATI 

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