Reproduction in Lower and Higher Plants - Short NOTES for 12th PART -1

 *Notes, Imp Points, Definitions, and Diagrams 

For Class 12th Biology Chapter 1 REPRODUCTION IN LOWER AND HIGHER PLANTS Based on HSC Syllabus. PART -1  

Introduction:-

Reproduction: - Reproduction is the production of young ones like parents.

Two categories of Reproduction:-

1) Asexual Reproduction         2) Sexual Reproduction




1.1 Asexual Reproduction

Definition: It is the process resulting in the production of genetically identical progeny from a single organism and inherits the genes of the parent.

Clones: Morphologically and genetically identical individuals.

Different Modes of Asexual Reproduction: - 

1) Fragmentation: - When multicellular organisms break into fragments, these fragments grow into new individuals.

Example - Spirogyra




2) Budding: - This mode of reproduction occurs by producing one or more outgrowths (buds) from the parent body. These buds on separation develop into a new individuals.

Example - Yeast

Budding in yeast - 12th biology



3) Spore Formation : Reproduction that occurs by flagellated, motile zoospores which can grow independently into new individuals.

Example: Chlamydomonas.

Spore Formation in chlamydomonas


Other methods of Asexual Reproduction 

  • Binary Fission - Amoeba, Paramoecium
  • Conidia Formation - Penicillium
  • Gemmules Formation - Sponges
VEGETATIVE REPRODUCTION

This mode of reproduction occurs in plants through their vegetative parts.

New plants formed are genetically identical to their parents.

Artificial Methods of Reproduction in Plants :



A. Cutting : 
  • The small piece of any vegetative part of a plant having one or more buds is used for propagation.
  • Stem cutting - Rose, Bougainvillea, Leaf Cutting - Sansevieria, Root Cutting - Blackberry
B. Grafting :

Here parts of two plants are joined in such a way that they grow as one plant.

Process: Part of the stem containing more than one bud (Scion) is joined onto a rooted plant called stock, which is called Grafting.

When only one bud is joined on the stock, it is called bud grafting.

Eg: Apple, pear, rose, etc.

C. Tissue culture : 

In this method, a small amount of plant tissue is carefully grown to give many plantlets.

The micropropagation method is also used nowadays.


    
The next part will become soon 
Follow me for next part-2. 
PREM PRAJAPATI.

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