Children everywhere wonder about the world around them. The questions they ask are the beginning of scientific inquiry. Given below are some questions that children in India have asked Professor Yash Pal and Dr Rahul Pal as reported in their book, Discovered Questions (NCERT, 2006).(i) What is DNA fingerprinting? What are its uses?(ii) How do honeybees identify their own honeycombs?(iii) Why does rain fall in drops?Can you answer these questions? You will find Professor Yash Pal’s and Dr Rahul Pal’s answers (as given in Discovered Questions) on page 75.
Answers
Answer:
DNA profiling or fingerprinting is the process of determining an individual's DNA characteristics, called a DNA profile, that is very likely to be different in unrelated individuals, thereby being as unique to individuals as are fingerprints.
It is used for the following purposes:
1. As a forensic technique in criminal investigation
2. To clarify paternity
3. To study plant and animal populations
(ii) Honeybees use the sun as a guide and are worldly-wise at navigation. They are said to have a sharp memory and a unique pattern of direction guidance i.e. dance. Their dance stipulates the distance and direction of the food source with respect to the direction of the sun.
(iii) Water rises in the form of vapours to form a dense cloud when the air is below the dew point. All the vapor in a cloud doesn’t condense in one go. These vapours condense slowly on dust particles present in the air. These dust particles combine to form a heavier particle. When these heavy particles start falling, they absorb more moisture and reach the ground as droplets.
Answer:
DNA fingerprint is a test to identify and evaluate the genetic information-called DNA (deoxyribonucleic acid) in a person's cells. DNA determines the form and function of the cell. Every person has a different DNA information.
DNA fingerprinting is used to:-
Determine a person's parents or siblings
Solve crimes (forensic science). Blood, semen, skin, or other tissue left at the scene of a crime are examined.
Identify a body.
(ii) Honeybees secrete chemicals that leaves indication for the fellow honeybees to reach a source of nectar or honeycomb. Apart from that, they use manifold dance patterns for communication.
(iii) Water is in a condensed state in the atmosphere. After condensation, the water clings around dust particles, salt or microrganisms etc in the atmosphere to form rain. As soon as, these droplets become too heavy to float, they start falling down to the ground due to the gravitational pull of the earth. So, rain does not come down as a large pool of water