Question

Your subject teacher gave you to complete the tables given below. Note a few points while doing the task. Fill in the space with correct elements.

1. 'Ploidy' word has been used in Table 1. What does it mean?
2. Where did the word chromosome come from?
3. What does monoploidy, diploidy, tetraploidy and pentaploidy mean?
4. What does 2n or 2x mean?
5. Find the meaning of: (a) genome (b) somatic.

Table 1. Plants
Crops	Chromosome number	Ploidy level
Rice		Diploid
Potato	2x = 48
	2x =	Tetraploid
Tomato
	3x =	Triploid

 

Table 2. Animals
Name	Chromosome number	Genus and species
Cat
	Canis familiaris
		38
	Ovis aries
		60
Horse

Answer 1

1. Ploidy refers to the number of complete sets of chromosomes present in a cell or organism.
2. The word chromosome is derived from two Greek words: “chroma” meaning colour and “soma” meaning body, because chromosomes readily take up stains and become coloured under a microscope.
3. 1. Monoploidy (x): One basic set of chromosomes.
   2. Diploidy (2x): Two sets of chromosomes.
   3. Tetraploidy (4x): Four sets of chromosomes.
   4. Pentaploidy (5x): Five sets of chromosomes.
4. 2n or 2x means that the cell has two complete sets of chromosomes, i.e. it is diploid.
5. 1. The genome is the complete set of genetic material present in an organism.
   2. Somatic refers to the body cells of an organism, excluding reproductive cells or gametes.

Table 1. Plants
Crops	Chromosome number	Ploidy level
Rice	2x = 24	Diploid
Potato	2x = 48	Tetraploid
Cotton	2x = 52	Tetraploid
Tomato	2x = 24	Diploid
Banana	3x = 33	Triploid

 

Table 2. Animals
Name	Chromosome number	Genus and species
Cat	Felis catus	38
Dog	Canis familiaris	78
Fox	Vulpes vulpes	38
Sheep	Ovis aries	54
Cow	Bos taurus	60
Horse	Equus caballus	64