Recombination 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.
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.
A 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?
Explain the genetic basis of blood grouping in human population.
In humans, the blood groups are controlled by a gene called gene I. It has three alleles, namely IA, IB and i. The plasma membrane of the red blood cells has sugar polymers that protrude from the surface and the kind of sugar is controlled by the gene. The alleles IA and IB produce a slightly different sugar while i do not produce any sugar. Since humans are diploid, each person can have different combinations of the three alleles. The alleles IA and IB are dominant over i therefore a combination of IA and iproduce blood group A, IB and I produce blood group B. The combination of IA, IB produces blood group AB which has both A and B types of sugar, because of co-dominance. The combination of IA and IA produce blood group A, IB and IB produce B blood group.
The type of blood group produced by the different combinations is shown in the table below:
How did Hershey and Chase established that DNA is transferred from virus to bacteria?