Restriction enzymes cut DNA molecules at a particular point by recognising a specific sequence . They are of two kinds – Exonucleases – remove Read More …
Category: Biology
Name two core techniques that helped develop biotechnology.
i) Genetic engineering : Techniques to alter the chemistry of genetic material & to introduce these into host organisms and thus change the phenotype of Read More …
Explain surgical methods and IUD’s are used in controlling human population.
Surgical method or sterilisation is a terminal method to prevent any more pregnancies. Surgical intervention blocks gamete transfer so as to prevent conception. In males it is called ‘vasectomy’, Read More …
Describe Biomagnification of DDT in an aquatic food chain.
Biomagnification refers to increase in concentration of the toxicant at successive trophic levels due to accumulation of a toxic substance by an organism. The toxic Read More …
Give an account if Jhum cultivation as a cause of deforestation.
The farmers in north-eastern states of India follow slash and burn agriculture / Jhum cultivation. They cut down the trees of the forest and Read More …
Mention the advantages of CNG over petrol / diesel in controlling vehicular pollution.
CNG burns most efficiently, so less air pollution. unlike petrol or diesel, very little of it is left unburnt. CNG is cheaper than petrol or Read More …
When a group of students from an institution went for an excursion to a place which is at an altitude of more than 3500 km , they experienced nausea, fatigue and heart palpitations. Predict the cause for this condition and how their bodies then get acclimatise?
At high altitudes atmospheric pressure is low, so body does not get enough of oxygen. The body acclimatizes by – Increasing production of RBC Read More …
How does the retrovirus replicate in the human body and interfere with its immune system? How can it be diagnosed and treated?
Virus enters into macrophages. Viral RNA replicates to form viral DNA with the help of reverse transcriptase. Viral DNA gets incorporated into host DNA. Read More …
How does the transmission of typhoid and pneumonia take place? Give names of the organisms causing them and the symptoms of these diseases.
Name of disease Mode of transmission Causative organism symptoms Typhoid Enter the intestine through food and /water , then migrate to other organs Read More …
How does inbreeding contribute in animal husbandry? Give the effect and solution of continued inbreeding .
Inbreeding increases homozygosity , helps to evolve a pureline in any animal, exposes harmful recessive genes that are eliminated by selection, helps in accumulation of superior Read More …