Tag: botany

• Tissue culture, also known as micropropagation, is a propagation method used to produce plants under sterile conditions. 
• This method uses plant explants (plant parts) or seeds that have been sterilized before being placed in containers with a growing medium (usually a gel) that has some nutrients added. 
• Micropropagation is the growing of plants from meristematic tissue or somatic cells of superior plants on nutrient suitable media under controlled aseptic physical conditions.

• Cells derived from a single cell through mitosis constitute a clone and the process of obtaining clones is called cloning (asexual progeny of a single individual make up a clone). 
• Plant tissue culture or micropropagation is the technique of maintaining and growing plant cells, tissues or organs especially on artificial medium in suitable containers under controlled environmental conditions.

• Micropropagation is a more recent practice for growing plants in a culture medium by providing them with all the necessary nutrients and inducing their growth artificially. So, statement A is correct.
• In the case of growth of plants through asexual means using tissue culture, first of all, the mass of cells is formed which is then differentiated into different cells and forms the entire plant body. This cell mass is called callus. So, statement B is also correct.
• Examples of micropropagation growth include orchids, dahlia, etc. So, the statement C is also correct.

Micropropagation is a tissue culture technique for plant propagation in which tissue is taken from a plant and grown in a laboratory to produce plants that are genetically identical to the parent. The small portion of plant tissue, sometimes only a single cell, is placed on a growth medium, typically containing sucrose as an energy source.

During cell division, spindle fibers attach to primary constriction of the chromosomes. Spindle fibres are mainly composed of microtubules which contract and relax to align the chromosomes at a particular orientation.

Bead-like thickened portions of leptotene chromosomes is chromomeres. During the leptotene stage, those duplicated chromosomes each consisting of two sister chromatids condense from diffuse chromatin into long, thin strands that are more visible within the cytoplasm.

A chromosome is composed of DNA and proteins. DNA are the hereditary units which mainly carries the information from one generation to the other. The functional segments of the DNA are known as genes. Proteins are mainly present as histones which form a complex structure known as a nucleosome.

Chromosomes in humans can be divided into two types, autosomes, and sex chromosome. The sex chromosomes carry the characters linked to a particular trait. The autosomes contain the rest of the genetic hereditary information. Human cells have 23 pairs of chromosomes (22 pairs of autosomes and one pair of sex chromosomes), giving a total of 46 per cell.