Points to Remember

Heredity (Science)

Points to Remember

·                 Variations are quite apparent among closely related groups of organisms.

·                 Mendel had choosen seven pairs of distinguishing traits: flower colour, position, seed colour, shape, pod colour, pod shape, stem length.

·                 Every pea plant has two ‘factors’ which are responsible for producing a particular character or trait is called allele.

·                 The process of acquiring characters or traits from parents is called ‘Heredity’.

·                 Each human cell contains 23 pairs of chromosomes. Out of these 22 pairs are called autosomes and one pair is called allosomes.

·                 A chromosome consists of the regions: primary constriction, centromere, secondary constriction, telomere and satellite.

·       Based on the position of the centromere, the chromosomes are classified as telocentric, acrocentric, sub metacentric and metacentric chromosomes.

·                 Each nucleotide of DNA consists of a deoxyribose sugar, a nitrogenous base and a phosphate group. Pairing is always between a purine and a pyrimidine.

·                 The sperm, produced by the father, determines the sex of the child. The mother is not responsible in determining the sex of the child.

·                 Mutation is an inheritable change in the genetic material of an organism.