To Access the full content, Please Purchase
A geneticist interested in studying variations and patterns of inheritance in living beings prefers to choose organisms for experiments with shorter life cycle. Provide a reason.Marks:1
A geneticist interested in studying variations and patterns of inheritance in living beings prefers to choose organisms with short life cycles for experiments because it enables the geneticist to study many generations of those organisms in their short lifespans.
Name the transcriptionally active region of chromatin in a nucleus.Marks:1
Euchromatin is the transcriptionally active region of chromatin in a nucleus.
State a reason for the increased population of dark coloured moths coinciding with the loss of lichens (on tree barks) during industrialization period in England.Marks:1
Industrial melanism was the reason for the increase in the population of dark-coloured moths along with the loss of lichens during industrialisation in England.
After industrialization, the tree trunks became darker with the deposits of soot and smoke. The number of dark moths increased as they were not easily visible to their predators however, the white-winged moths were easily picked up by the predators. Thus, dark ones were naturally selected and light ones fail to survive.
Indiscrimate diagnostic practices using X-rays etc., should be avoided. Give one reason.Marks:1
X-rays are potent mutagens and can cause adverse effects in children in the form of genital changes; i.e., they alter the genetic make-up of an organism.
What is Biopiracy?Marks:1
The illegal exploitation of biological material of a country by organisations or multinational companies without proper authorisation from the concerned country is known as biopiracy.
After a brief medical examination, a healthy couple came to know that both of them are unable to produce functional gametes and should look for an 'ART' (Assisted Reproductive Technique). Name the 'ART' and the procedure involved that you can suggest to them to help them bear a child.Marks:2
Differentiate between male and female heterogamety.Marks:2
Heterogamety means different sex gametes.
Male heterogamety includes human males having XY sex chromosomes and males of some insects, such as grasshopper and bugs, having XO sex chromosomes.
Female heterogamety includes females of some species of birds, fishes and insects. Females of butterfly and moth consist ZO sex chromosomes, while females of fish, reptiles and birds consist ZW sex chromosomes.
How has mutation breeding helped in improving the production of mung bean crop?Marks:2
Mutation breeding is a technique in which plants having desirable mutations can be selected and chosen as a source for breeding. It has helped mung bean production by providing resistance against yellow mosaic virus and powdery mildew (fungal disease).
Mention a product of human welfare obtained with the help of each one of the following microbes:
(c) Propionibacterium shermanii
a) Lactic acid bacteria (LAB); Lactobacillus is used in the production of curd from milk.
b) Saccharomyces cerevisiae is used in baking industry.
c) Propionibacterium shermanii is used in the production of cheese.
d) Aspergillus niger is used in the production of citric acid.
Many fresh water animals cannot survive in marine environment. Explain.Marks:2
Many freshwater fish cannot survive in the marine environment as their bodies are not adapted to the marine environment. Freshwater fish lose body water because of the hypertonic environment that has a higher concentration of salt in the surrounding water, making their survival difficult.