Principles of Inheritance and Variation Test - 12

Mendel’s factors that remain stable over generation to generation are called as gene. Genes are structural and functional unit of inheritance.

In diploid cells, genes which code for a pair of contrasting traits are known as alleles. One allele is dominant and other is recessive in features.

Chromosomes are structure in nucleus that appeared to double and divide just before each cell division that may be mitosis or meiosis.

Two alleles of gene pair are located on homologous site on homologous chromosomes. During gamete formation, homologous chromosome separate from each other carrying one set of allelomorphic genes.

Map distance is tools to find the distance between two genes on a chromosome. The genes closer to each other shows less number of crossing over percentage.

Blender experiment was carried by Hershey and Chase to prove that DNA is a genetic material. He carried experiment on Bacteriophage and E.coli having radioactive nitrogen and phosphorus.

The traits controlled by genes present on X-chromosome are called sex linked traits. Colour blindness, hemophilia etc. are sex linked traits.

complementary genes are one of two or more genes that when present together produce effects qualitatively distinct from the separate effect of any one of them.

Duplicate genes are two or more genes found on different chromosomes which produce the same or nearly same phenotypic effect in the dominant state. They produces same intensity of effect even when present together.

Physical association between two genes located on same chromosome is called linkage. The generation of non-parental gene combination is called recombination. Recombination is essential for generation of new traits in a species.