Differentiate between inbreeding and outbreeding.

Features Inbreeding Outbreeding Participating individuals It is the mating between closely related individuals. Outbreeding is the breeding of unrelated animals. Homozygosity It helps in the maintenance of homozygosity, thereby helping in the maintenance of the purity of a race. It results in the production of hybrids. Effect on productivity Repeated cross-breeding helps in the maintenance of superiority. Repeated inbreeding may lead to a decline in productivity

Explain out-breeding, out-crossing, and cross-breeding practices in animal husbandry.

Out-breeding is the mating between unrelated individuals, which may be between the animals of the same breeds but no common ancestors or between different breeds of individuals or different species within the same genus (inter-specific hybridisation). Thus, out-breeding can be classified into three: Out-crossing, Cross-breeding, and Interspecific hybridisation. Out-crossing is the mating of animals within the same breed, but having no common ancestors on either side of their pedigree up to 4-6 generations. The out-crossing helps to overcome inbreeding depression. The superior males of one breed are mated with superior females of another breed is called cross-breeding. Cross-breeding allows the combination of the desirable qualities of two different breeds. An example of cross-breeding is the crossing between two sheep breeds, Bikaneri ewes, and Merino rams to produce Hisardale, a new breed of sheep developed in Punjab.

How is 'somatic hybridization' carried out? Mention one example of a somatic hybrid.

Somatic hybridisation can be best defined as the process in which the protoplast of somatic cells of different varieties gets fused. This process is carried out on a suitable medium. In this process, isolation of protoplast by digesting cell wall takes place at first. Then the isolated protoplast of different varieties of plants with desired traits get fused. The hybrid protoplast is formed then, which is further grown to form the new hybrid plant. For example, Pomato, this somatic hybrid, is produced by fusion of potato & tomato.

You have obtained a high-yielding variety of tomato. Name and explain the procedure that ensures retention of the desired characteristics repeatedly in large populations of future generations of the tomato crop.

Plant breeding is the procedure that ensures retention of the desired characteristics repeatedly in large populations of future generations of a crop. It refers to the genetic improvement of crop plants. It aims to create and maintain desired plant characteristics such as better yield, disease and pest resistance and increased tolerance to environmental stress. To retain the desired traits in a plant, hybridisation (crossing) of pure lines is carried out, followed by artificial selection. Thus, these procedures ensures retention of the desired characteristics repeatedly in large populations of future generations of the tomato crop.