Biology
(i) List any two major activities of the Red Cross.
(ii) Write any two major reasons for the population explosion in the world.
(iii) Write the names of four nitrogenous bases in a DNA molecule.
Answer
(i) Two major activities of the Red Cross are:
- To extend relief and help to the victims of any calamity — fire, flood, famine, earthquakes etc.
- To procure and supply blood for the victims of war and other calamities.
(ii) Two major reasons for the population explosion in the world are:
- Better health care at all age groups and fewer deaths due to better medical aids.
- Large scale immunization against communicable diseases.
(iii) The four nitrogenous bases in the DNA molecule are Guanine, Thymine, Adenine and Cytosine.
Related Questions
Briefly explain the following terms:
(i) Genes.
(ii) Cytokinesis in plant cells.
(iii) Guttation.
(iv) Diabetes insipidus.
(v) Disinfectants.
(i) Draw a well labelled diagram to show the anaphase stage of mitosis in a plant cell having four chromosomes.
(ii) State any two harmful effects of acid rain.
(iii) Expand the following biological abbreviations :
- NADP
- ACT
The figure given below shows the epidermal cells of an onion bulb. This cell was then transferred to a drop of sugar solution.
(i) Draw a well labelled diagram of the epidermal cell as it would appear after immersion in a strong sugar solution.
(ii) What scientific term is used for the changes as shown in (i) above ?
(iii) What should be done to restore the cell back to its original condition ?
(iv) Give the scientific term for the recovery of the cell as a result of the step taken in (iii) above.
(v) Define the term osmosis.
Give biological reasons for the following :
The hand automatically shows the direction to turn a cycle without thinking.