Human Health and Disease — BIOLOGY STD 12 Science — Question

1. Which of the following holds true for Ravi's illness?

1. Ravi was suffering from a communicable disease that is transmitted through vector.
2. Ravi was suffering from a communicable disease that is transmitted through faecal oral route.
3. Ravi was suffering from a non-communicable disease like anaemia.
4. Ravi was suffering from a non-communicable disease like Down's syndrome.

2. Select the correct statement.

1. Ravi contracted a disease caused by air borne microbes.
2. Ravi could have suffered a nutritional disorder.
3. Ravi suffered a non-contagious disease.
4. Both (b) and (c)

3. Which could be correctly said for Rajesh's illness?

1. Rajesh's illness was due to a microbial infection.
2. Rajesh's illness could be contagious or non-contagious.
3. Rajesh's illness could be cured by antibiotics.
4. All of these

4. Which of the following may depicts Ravi's and Rajesh's illness?

5. Assertion: Diabetes mellitus is a non-communicable disease which can be completely cured.

Reason: Diabetes mellitus is caused by deficiency of aldosterone hormone.

1. Both assertion and reason are true, and reason is the correct explanation of assertion.
2. Both assertion and reason are true, but reason is not the correct explanation of assertion.
3. Assertion is true, but reason is false.
4. Both assertion and reason are false.

1. Which of the following is not considered as microorganisms?

1. Bacteriophage.
2. Streptococcus.
3. Porphyra.
4. Staphylococcus.

2. Select the incorrect option regarding the characteristics of lactic acid bacteria.

1. They are rod-shaped or spherical.
2. They are Gram positive.
3. They take part in carbohydrate fermentation.
4. They are acid intolerant.

3. Which of the following is not a lactic acid producing bacteria?

1. Streptococcus.
2. Lactococcus.
3. Saccharomyces.
4. Enterococcus.

4. Probiotics are:

1. Gut friendly live bacteria.
2. Acid balancing alternated bacteria.
3. Beneficial amount of dead bacteria.
4. Gram negative attenuated bacteria.

5. Assertion: Lactobacillus bacteria do not retain crystal violet stain while staining.

Reason: Lactobacillus have a very thin layer of peptidoglycan layer in their cell wall.

1. Both assertion and reason are true and reason is the correct explanation of assertion.
2. Both assertion and reason are true but reason is not the correct explanation of assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.

1. A dithecous another consists of (A) microsporangia, (B) in each lobe.

Select the option that correctly fills the blanks.

2. The given diagram shows microsporangium of a mature anther. Identify A, B and C.

3. The function of labelled part X is:

1. Dehiscence.
2. Mechanical.
3. Nutrition.
4. Protection.

4. Select the incorrect statement.

1. Microsporangium is generally surrounded by four wall layers-epidermis, endothecium, middle layers and tapetum.
2. Outer three layers perform functions of protection and dehiscence of anthers.
3. Cells of tapetum possess dense cytoplasm and generally have more than one nucleus.
4. Cells of tapetum undergo meiosis and produce microspore tetrads.

5. Which function oftapetum is correct?

1. Helps in pollen wall formation.
2. Transportation of nutrients to inner side of another.
3. Synthesis of callase enzyme for separation of microspore tetrads.
4. All of these.

1. Which of the following is correct regardingT(L), M(L), T(M) and M(M)?

1. T(L) and M(L) will fall while T(M) and M(M) will increase.
2. T(L) and M(L) will increase while T(M) and M(M) will fall.
3. T(L) and M(L) will fall, T(M) will remain same and M(M) will increase.
4. T(L) and M(L) will remain same, T(M) and M(M) will decrease.

2. It can be said that some animals in their evolutionary development preferred to be ectotherms than endotherms. Which of the following can be the best suited reason for it?

1. The metabolic reactions of these organisms can occur at a very wide range of temperature.
2. Maintaining homeostasis is an energetically expensive process.
3. The enzymes of these organisms are functional at high temperatures.
4. Both (b) and (c).

3. Organisms that can maintain a constant internal temperature are called.

1. Homoeothermic
2. Poikilothermic
3. Oligothennic
4. Heterothennic

4. An animal that survives at temperature of 10ºC and 40ºC both can be placed under the category of:

1. Ectotherm.
2. Endotherm.
3. Modifiers.
4. Migratory organisms.

5. Study the graph carefully and select the correct option.

1. X could be desert lizard.
2. Y could be mouse.
3. Z could be desert lizard.
4. Both (a) and (b).

1. Why the name single cell protein is applied?

1. It contains only one type of protein.
2. It is obtained from unicellular edible microbes.
3. It contains only one type of microorganism.
4. All of these.

2. Which of the following is considered under single cell protein?

1. Algae.
2. Fungi.
3. Cyanobacteria.
4. All of these.

3. Microorganisms can be a useful food resource for increasing human population because:

1. These are easy to harvest.
2. These can grow in water system.
3. They have a high rate of multiplication thus producing huge biomass.
4. They have high level of nucleic acid.

4. Single cell protein can be grown from:

1. Waste water.
2. Animal manure.
3. Sewage.
4. All of these.

5. Assertion: Production of single cell protein reduces pollution.

Reason: Single cell protein can be grown from waste water and even sewage.

1. Both assertion and reason are true and reason is the correct explanation of assertion.
2. Both assertion and reason are true but reason is not the correct explanation of assertion.
3. Assertion is true but reason is false.
4. Both assertion and reason are false.