Mention three main reasons for the sharp rise in ‘human population’ in the world.
Reasons for the sharp rise in human population in the world are as follows:
1. Better health care is available for all age groups. There are advanced facilities,
doctors and medicines available.
2. Food shortage has been overcome due to the Green Revolution. Better quality
food is produced and is available to all.
3. There are now fewer deaths as compared to ancient times. This is because of the
discovery of medicines and vaccines and large-scale immunization which have controlled and even wiped out many diseases.
Account for the following briefly:
(iv) Herbaceous plants growing in well-watered soils are found to wilt on a hot day.
Draw a diagram of the nucleus of a cell, having chromosome number 6, as it would appear in the metaphase stage of mitosis and label the following parts in the diagram:
1. Aster
2. Achromatic spindle
3. Chromatid
4. Centromere
Mention the difference between mitosis and meiosis with reference to
1. Number of daughter cells formed at the end of the division.
2. The chromosome number of the daughter cells formed.
