Biology
Briefly answer the following questions:
(i) State two reasons for the increase of population in India.
(ii) What is the significance of amniotic fluid?
(iii) What is the function of ear ossicles?
(iv) Mention any two activities of the WHO.
(v) State Mendel's law of Dominance.
Answer
(i) The two main reasons for the rapid increase of population in India are —
- Illiteracy — Most of the rural population which forms the bulk of our society are still illiterate, ignorant, and follow various superstitions. They also do not know the functioning of the human reproductive system.
- Economic reasons — Children are considered to be helping hands to increase family income.
(ii) Amniotic fluid fills the space between the amnion and the embryo. It's important functions are:
- It keeps even pressure all around the embryo.
- It prevents sticking of the foetus to the amnion.
(iii) The ossicles increase the intensity of the sound vibrations received by the tympanum and transmit them to the inner ear.
(iv) Two activities of the WHO —
- To collect & supply information about occurrence of diseases of epidemic nature.
- To promote and support projects for research on diseases.
(v) Law of Dominance — Out of a pair of contrasting characters present together, only one is able to express itself while the other remains suppressed. The one that expresses is the dominant character and the one that is unexpressed is the recessive one. The recessive character can express only when the pair consists of both recessives (homozygous recessive).
Related Questions
The diagrams given below are cross sections of blood vessels:
(i) Identify the blood vessels A, B and C.
(ii) Name the parts labelled 1 to 3.
(iii) Name the type of blood that flows through A.
(iv) Mention one structural difference between A and B.
(v) In which of the above vessels does exchange of gases actually take place?
An apparatus as shown below was set up to investigate a physiological process in plants. The setup was kept in sunlight for two hours. Droplets of water were then seen inside the bell jar. Answer the questions that follow:
(i) Name the process being studied.
(ii) Explain the process named above in Q.3 (a) (i).
(iii) Why was the pot covered with a plastic sheet?
(iv) Suggest a suitable control for this experiment.
(v) Mention two ways in which this process is beneficial to plants.
(vi) List three adaptations in plants to reduce the above mentioned process.
Differentiate between the following pairs on the basis of what is mentioned within brackets:
Diffusion and Osmosis (Definition)
Give the biological / technical terms for the following:
(i) A mixture of smoke and fog.
(ii) Capacity of our body to resist diseases.
(iii) Fixing of developing zygote on the uterine wall.
(iv) The permanent stoppage of menstruation at about the age of 45 years in a female.
(v) The hormone increasing reabsorption of water by kidney tubules.
(vi) A thin membrane covering the entire front part of the eye.
(vii) The lens of eye losing flexibility resulting in a kind of long-sightedness in middle aged people.
(viii) The number of persons living per square kilometre at any given time.
(ix) The sound produced when the atrio-ventricular valves close in the heart.
(x) The process by which white blood cells engulf bacteria.