misc questions that are difficult

Question 1

The sporozoites that cause infection when a female Anopholes mosquito bites a human being are formed in
a) Liver of human
b) RBCs of mosquito
c) Salivary glands of mosquito
d) Intestine of mosquito

Answer 1

(d) Intestine of mosquito

Question 2

Name the toxin responsible for causing the symptoms of malaria

Answer 2

Haemozoin

Question 3

Antibody which is most effective in allergies

Answer 3

IgE

Question 4

Name a vaccine produced by recombinant DNA technology

Answer 4

Hepatitis B vaccine

Question 5

What causes shivering in a malaria patient?

Answer 5

When the RBC ruptures and releases the toxin haemozoin, it causes fever and chills

Question 6

Name the malarial parasite that causes malignant malaria

Answer 6

Plasmodium falciparum

Question 7

Differences between Humoral immunity and cell mediated immunity

Answer 7

1. HI: Consists of B cells
   CMI: Consists of T-cells
2. HI: Produced antibodies circulate in the body
   CMI: Produce 4 types of T-cells
3. HI: Against viruses and bacteria
   CMI: against all pathogens including fungi and protozoa, bacteria, viruses
4. HI: Doesn’t respond to transplants, cancer cells, extra-cellular microbes
   CMI: Reacts against transplants, cancer cells, autoimmune disorders, intracellular microbes

Question 8

In a DNA strand the nucleotides are linked together by
(a) glycosidic bonds
(b) phosphodiester bonds
(c) peptide bonds
(d) hydrogen bonds

Answer 8

(b) phosphodiester bonds

Question 9

In E. coli the lac operon gets switched on when
(a) lactose is present and it binds to the repressor
(b) repressor binds to operator
(c) RNA polymerase binds to the operator
(d) lactose is present and it binds to RNA polymerase

Answer 9

(a) lactose is present and it binds to the repressor

Question 10

The amino acid attaches to the tRNA at its
(a) 5’- end
(b) 3’ – end
(c) anticodon site
(d) DHU loop

Answer 10

(b) 3’ – end

Question 11

In Miller’s experiment, the gaseous mixture in the flask contained:
(a) Methane, ammonia, carbon dioxide and helium
(b) Carbon dioxide, hydrogen, water vapour and ammonia
(c) Ammonia, methane, hydrogen and water vapour
(d) Hydrogen, ammonia and methane and helium

Answer 11

(a) Methane, ammonia, carbon dioxide and helium

Question 12

Neo–Darwinism is:
(a) Natural selection theory
(b) Modern mutation theory
(c) Modern synthetic theory
(d) Population theory

Answer 12

(c) Modern synthetic theory

Question 13

What is the effect of high pH on sperm?
(a) High activity leading to early death
(b) Sluggish, longer life
(c) High activity, longer life
(d) No effect

Answer 13

(c) High activity, longer life

Question 14

Which of the following can be used as biofertilizer?
(a) Anabaena
(b) Nostoc
(c) Oscillatoria
(d) All the above

Answer 14

(d) All the above

Question 15

The sperm of Drosophila contains _____ number of chromosomes:
(a) 4
(b) 46
(c) 23
(d) 8

Answer 15

(a) 4

Question 16

difference between first trophic level of detritus food chain and grazing food chain

Answer 16

detritus food chain: decomposers form the first trophic level
grazing food chain: green plants form the first trophic level

Question 17

grw All the primary productivity is not available to a herbivore

Answer 17

a considerable amount is utilised by the plants in respiration, while some is lost as heat into the environment.

Question 18

what four features must a biomolecule have to act as genetic material

Answer 18

(i) It should be able to replicate.
(ii) It should be structurally and chemically stable.
(iii) It should be able to undergo slow mutations.
(iv) It should be able to express itself in the form of Mendelian characters.

Question 19

A woman has certain queries as listed below, before starting with contraceptive pills. Answer them.
(a) What do contraceptive pills contain and how do they acts as contraceptive?
(b) What schedule should be followed for taking these pills?

Answer 19

(a) Contraceptive pills contain progesterone or estrogen or progesterone-estrogen combinations.
They functions as contraceptives by:
inhibiting ovulation
Inhibiting implantation
Altering the quality of the cervical mucus to prevent or stop the entry of sperms.
(b) The oral contraceptive pills are to be taken daily for 21 days, preferably within the first five days of the menstrual cycle.

Question 20

List any four ways by which GMOs have been useful for enhanced crop output.

Answer 20

1. Increased food production
2. Resistant to extreme conditions like extreme cold,drought,heat stress
3. Some crops are made pest resistant by genetic modification which cuts down the usage of pesticides
4. Increased efficiency of mineral usage by plants and prevents early exhaustion of stability of soil

Question 21

Write the situations as discovered by the ecologists when the value of ‘Z’ (slope of the line) lies between (i) 0.1 and 0.2 (ii) 0.6 and 1.2. What does ‘Z’ stand for?
(c) When would the slope of the line ‘b’ become steeper?

Answer 21

(i) for a small area
(ii) for a large area such as a continent

Z stands for slope of the line

It becomes steeper when wide areas such as continents are are considered for species-area relationships