Short Answer TypeRecombination DNA technology is of great importance in the field of medicine. With the help of a flow chart, show how this technology has been used in preparing genetically engineered human insulin.
Following the collision of two trains a large number of passengers are killed. A majority of them are beyond recognition. Authorities want to hand over the dead to their relatives. Name a modern scientific method and write the procedure that would help in the identification of kinship.
DNA fingerprinting is the modern scientific method used for the identification of kinship. Variable Number of Tandem Repeats (VNTR) are satellite DNAs that show high degree of polymorphism. They are used as probes in DNA fingerprinting.
Procedure of DNA Fingerprinting:
i. Firstly, DNA from the individual and closest relative is isolated and cut with restriction endonucleases.
ii. Fragments are separated according to their size and molecular weight through gel electrophoresis of both the individual and the relative.
iii. Fragments separated through electrophoresis gel are blotted (immobilised) on a synthetic membrane such as nylon or nitrocellulose.
iv. Immobilised fragments are hybridized with a VNTR probe.
v. Hybridised DNA fragments can be detected by autoradiography. The autoradiograph of the individual and the relative is compared.
VNTRs vary in size, ranging from 0.1 to 20 kb. Hence, in the autoradiogram, a band of different sizes will be obtained. These bands are characteristics of an individual. They are different in each individual, except in the case of identical twins. The presence of similarities, between the individual and the relative helps to determine the kinship.
Hence the body of the individual can be handed over to their relatives.
Many plant and animal species are on the verge of their extinction because of loss of forest land by indiscriminate use by the humans. As a biology student what method would you suggest along with its advantages that can protect such threatened species from getting extinct?
Since October 02, 2014 'Swachh Bharat Abhiyan' has been launched in our country.
(a) Write your views on this initiative giving justification.
(b) As a biologist name two problems that you may face while implementing the programme in your locality.
(c) Suggest two remedial methods to overcome these problems.
Long Answer TypeA flower of tomato plant following the process of sexual reproduction produces 240 viable seeds.
Answer the following questions giving reasons:
(a) What is the minimum number of pollen grains that must have been involved in the pollination of its pistil?
(b) What would have been the minimum number of ovules present in the ovary?
(c) How many megaspore mother cells were involved?
(d) What is the minimum number of microspore mother cells involved in the above case?
(e) How many male gametes were involved in this case?
During the reproductive cycle of a human female, when, where and how does a placenta develop? What is the function of placenta during pregnancy and embryo development?
How did Hershey and Chase established that DNA is transferred from virus to bacteria?
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