Q16 of 42 Page 1

Name the technique and the property of plant cells that can help to grow somaclones of certain desired variety of apple. Explain how somaclones of apple can be obtained in the lab so as to get the desired variety on a large scale.

• Tissue culture technique by which the whole plants can be regenerated from explants, i.e., any part of a plant. This capacity to generate a whole plant from any cell/explant is called totipotency.


• To grow somaclones of apple in a lab to get a desirable variety on a large scale as follow:


1. From the apple plant, any part was taken out and grown in a test tube, under sterile conditions.


2. The explant is transferred into a special nutrient media. The composition of media is important to provide all nutrients like a carbon source such as sucrose and also inorganic salts, vitamins, amino acids and growth regulators like auxins, cytokinins, etc.


3. Regularly the replacement of medium is required without contamination.


4. Each of these plants will be genetically identical to the original plant from which they were grown, i.e., they are the somaclones of apple.


More from this chapter

All 42 →
14

(a) Draw a sectional view of human ovary. Label the following parts:

(i) Primary follicle


(ii) Secondary oocyte


(iii) Graafian follicle


(iv) Corpus luteum


(b) Name the hormones influencing follicular development of corpus luteum.


OR


(a) Draw an L.S. of pistil showing pollen tube entering into the embryo sac. Label the following:


(i) Nucellus


(ii) Antipodals


(iii) Synergids


(iv) Micropyle


(b) Write the functions of the following :


(i) Synergids


(ii) Micropyle


 15

Given below is the representation of a relevant part of amino acid composition of the β-chain of haemoglobin, related to the shape of human red blood cells.


(a) Is this representation of the sequence of amino acids indicating a normal human or a sufferer from a certain blood related genetic


disease? Give reason in support of your answer.


(b) Why is the disease referred to as a Mendelian disorder? Explain.


OR


Name the kind of diseases/disorders and any two symptoms that are likely to occur in humans if:


(a) Mutation in the gene that codes for an enzyme phenylalanine


hydroxylase occurs.


(b) The karyotype is XXY.


 17

Study the graph given below and answer the questions that follow:


(i) The curve ‘b’ is described by the following equation:



What does ‘K’ stand for in this equation? Mention its significance.


(ii) Which one of the two curves is considered a more realistic one for most of the animal populations?


(iii) Which curve would depict the population of a species of deer if


there are no predators in the habitat? Why is it so?


 18

‘‘A very small sample of tissue or even a drop of blood can help determine paternity.’’ Provide a scientific explanation to substantiate how it is possible.