Plus Two Botany Class Notes First Bell 2.0

CHAPTER 1 

REPRODUCTION IN ORGANISMS 

Important Questions and Answers 

1.What is mean by lifespan?

Each and every organism can live only for a certain period time. The period from birth to the natural death of an organism represents its life span.

2. Find life span of following organisms ?

Elephant, dog,  cow, horse, rose, banana tree, crocodile,  crow, parrot, fruit fly, banyan tree,  rice plant , tortoise and butterfly. 

• Elephant       -  40 - 65 years
• Dog                 -  10 - 13 years
• Cow                -  18 - 22 years
• Horse             -   25 - 30 years
• Rose               -   5 - 7 years 
• Banana tree  - 25 years
• Crocodile      -  60 years
• Crow              - 15 years
• Parrot            - 140 years
• Fruit fly          - 30 days
• Banyan tree  - 200 years
• Rice plant     - 3- 4 months
• Tortoise      - 100 - 150 years
• Butterfly     - 1 – 2 weeks

3.What is reproduction?

Reproduction is defined as a biological process in which an organism gives rise to young ones (offspring) similar to itself. The offspring grow, mature and in turn produce new offspring. Thus, there is a cycle of birth, growth and death. Reproduction enables the continuity of the species, generation after generation.

4.What are the two types of reproduction?

   Asexual and sexual reproduction. 

5.What is Asexual reproduction 

In this method, a single individual is capable of producing offspring. As a result offspring that are produced are not identical to one another but are also exact copies of their parent.

 6.What is mean by the term clone ?

 The term clone is used to describe such morphologically and genetically similar individuals.

7.what is binary fission and write some examples for it ?

Many single-celled organisms reproduce by binary fission, where a cell divides into two halves and each rapidly grows into an adult Ex: Amoeba, Paramecium.

8. What is mean by the term encystation
 
A three-layered hard covering or cyst around itself. This phenomenon is  termed as encystation.

9. Explain  the asexual reproduction of amoeba

Under unfavourable condition the Amoeba withdraws its pseudopodia and secretes a three-layered hard covering or cyst
around itself. This phenomenon is  termed as encystation. When favourable conditions return, the  encysted Amoeba divides by multiple fission and produces many minute amoeba or pseudopodiospores the cyst wall bursts out, and the spores are  liberated in the surrounding medium to  grow up into many amoebae. This phenomenon is known as sporulation

10. What are the reproductive structures of asexual reproduction? 
      
Conidia , buds , gemmules and zoospores and fragmentation.

For Chapter -01 Reproduction Notes Part-02- Click Here