816: Which of the following is/are found in plant cells but not in those of animals ?
(a) Plastid & Cellular wall
(b) Chromosome
(c) Mitochondria & Golgi apparatus
(d) Cell wall & lysozyme
817: Electrically charged particles from space travelling at speeds of several hundred km/sec can severely harm living beings if they reach the surface of the Earth. What prevents them from reaching the surface of the Earth?
(a) The Earth's magnetic field diverts them towards its poles
(b) Ozone layer around the Earth reflects them back to outer space
(c) Moisture in the upper layers of atmosphere prevents them from reaching the surface of the Earth
(d) None of the statements (a), (b) and (c) given above is correct
818: Consider the following statements:
1. Femur is the longest bone in the human body.
2. Cholera is a disease caused by bacteria.
3. Athlete's foot's is a disease caused by virus.
Which of the statements given above are correct?
(a) 1 and 2
(b) 2 and 3
(c) 1 and 3
(d) 1, 2 and 3
819: Haemophilia is a genetic disorder which leads to
(a) decrease in haemoglobin level
(b) rheumatic heart disease
(c) decrease in WBC
(d) non-clotting of blood
820: Which one of the following statements is not correct?
(a) Hepatitis B virus is transmitted much like HIV.
(b) Hepatitis B. unlike Hepatitis C, does not have a vaccine.
(c) Globally, the number of people infected with Hepatitis B and C viruses arc several times more than those infected with HIV.
(d) Some of those infected with Hepatitis B and C viruses do not show the symptoms for many years.