question_answer

How are morphological and physiological characters of plants are associated with the resistance to insect pests? Provide five examples, describing features and the name of insect pests to which each plant is resistant.

Or

Breeding of animals is mainly done to increase the possibility of obtaining the offspring of desired traits. Discuss the ways being employed to achieve a successful animal breeding. According to you, which is the best method among these discussed methods and why?

Answer:

Resistant to insect pests is generally controlled and mainfested in the form of morphological, physiological and biochemical characters in different plants. Few examples of such adaptations in different plants are listed below

(i) Wheat It possess hairy leaves due to which it is resistance to cereal leaf beetle.

(ii) Maize It contains high aspartic acid and low nitrogen and sugar content due to which it is resistant to stem borer.

(iii) Wheat The solid stem of these plants make them resistant to saw fly.

(iv) Cotton Its leaves are smooth and do not contain nector and hence, it is resistance to bollworms.

(v) Cotton The hairy leaves of this plant make them resistant to jassids.

Or

Animal breeding is an important part of animal husbandry. It aims to increase the yield of animals and improve the desirable qualities of produce.

Breeding can be divided as given in the chart below

(i) Inbreeding refers to the mating between closely related individuals within the same breed for 4-6 generations.

Continued inbreeding reduces fertility and even productivity. This is called inbreeding depression.

(ii) Outbreeding is the breeding of unrelated animals, either of the same breed but not having common ancestors for 4-6 generations (out-crossing) or of different breeds (cross-breeding) or even different species (interspecific hybridisation).

It can be of the following types

(a) Out-crossing is the practice of mating of animals within the same breed, but having no common ancestors on either side of their pedigree upto 4-6 generations.

(b) Cross-breeding refers to the mating of superior males of one breed with superior females of another breed.

(c) Interspecific hybridisation refers to crossing between male and female animals of two different related species. (iii) To achieve successful animal breeding two methods are employed which are given below

Artificial insemination is a method of controlled breeding. The semen from selected male parent is injected into the reproductive tract of selective female parent.

MOET (Multiple Ovulation Embryo Transfer

Technology) It is a programmer employed for herd improvement.

According to me, artificial insemination is the best method for animal breeding because, it offers following advantages

(a) Helps to overcome problems related to normal mating.

(b) Semen can be stored and frozen for the later use.