Micro-organisms Quiz

Antibiotics function by either killing bacteria or inhibiting their multiplication, targeting specific bacterial structures or processes by: (i) Inhibiting protein synthesis (ii) Damaging DNA (iii) Destroying cell walls

1. Only (i)
2. Only(ii)
3. Only (iii)
4. (i), (ii) and (iii)

Answer: (d) (i), (ii) and (iii)

Fill in the blanks to complete the statement. Yeast is useful in baking due to its ability to __(i)___sugars, producing __(ii)___ and __(iii)__. The __(ii)___causes the dough to rise, making baked goods light and fluffy.

1. (i) digest, (ii) oxygen, (iii) water
2. (i) ferment, (ii) carbon dioxide, (iii) ethanol
3. (i) break, (ii) methane, (iii) nitrogen
4. (i) dissolve, (ii) hydrogen, (iii) alcohol

Answer: (b) (i) ferment, (ii) carbon dioxide, (iii) ethanol

Identify the rows with correct set of information. Row Disease Causative microbe Transmission method a Hepatitis B Bacteria Contaminated water and air b Sleeping sickness Protozoa Tsetse fly c Foot and mouth disease Virus Direct contact d Malaria Fungi Infected blood and other body fluid

1. a and b
2. a and c
3. b and c
4. c and d

Answer: (c) b and c

Oliver is making homemade curd for the first time. His grandmother advises him to add a small amount of curd to the milk as an inoculum to help it set into curd. This inoculum primarily contains:

1. Lactobacillus
2. Yeast
3. Azotobacter
4. Penicillium

Answer: (a) Lactobacillus

A biotechnology company develops a bacterial strain capable of degrading plastics. The bacteria thrive only in aerobic conditions. In which of the following environments would the bacteria be most effective?

1. Deep layers of landfill
2. Shallow soil with good aeration
3. Anaerobic digesters
4. Ocean depths

Answer: (b) Shallow soil with good aeration

A city’s wastewater treatment plant uses biological treatment methods involving microbes to clean the wastewater. The plant manager explains that specific types of microbes play a crucial role in breaking down organic matter, removing pollutants, and reducing harmful pathogens. The types of microbes that are commonly used in wastewater treatment are: (i) Bacteria (ii) Virus (iii) Fungi (iv) Algae (v) Protozoa

1. (i), (ii) and (iii)
2. (ii), (iii), (iv) and (v)
3. (iii) and (iv) only
4. (i), (iii), (iv) and (v)

Answer: (d) (i), (iii), (iv) and (v)

Which row in the table incorrectly classifies the microbes? Harmful microorganism Beneficial microorganism A Anabaena Moulds B Clostridium Saccharomyces cerevisiae C HIV Acetobacter D Trypanosoma Aspergillus niger

1. A
2. B
3. C
4. D

Answer: (a) A

Without bacteria and fungi, the Earth would become a massive pile of waste. The correct justification for this statement is: (i) Bacteria and fungi consume all organic matter, preventing waste accumulation. (ii) Bacteria and fungi are decomposers that break down organic matter. (iii) Bacteria and fungi recycle nutrients back into the ecosystem. (iv) Bacteria and fungi feed on inorganic substances, eliminating waste.

1. (i) and (ii)
2. (ii) and (iii)
3. (iii) and (iv)
4. (i) and (iv)

Answer: (b) (ii) and (iii)

Select the correct option regarding the given statements. Statement 1 (S1): Nitrogen is absorbed by the plants in the form of nitrates. Statement 2 (S2): Nitrate is water-soluble and moves easily toward plant roots along with the water they absorb.

1. S1 and S2 both are correct and S2 correctly explains the S1.
2. S1 is correct but S2 is incorrect.
3. S2 is correct but S1 is incorrect.
4. Both S1 and S2 are incorrect.

Answer: (a) S1 and S2 both are correct and S2 correctly explains the S1.

Carefully read through the passage and answer the following question. Introduction to Virus Viruses are the smallest of all microbes, relying on the cellular machinery of a living host to reproduce. The basic structure of a virus consists of nucleic acid enclosed within a protein coat known as a capsid. In some viruses, this nucleocapsid is further surrounded by a lipid membrane. A single virus, known as a virion, injects its genetic material—either RNA or DNA—into a host cell. Within the cell, the virus replicates and eventually releases new virions, ready to infect other cells. Despite their tiny size, viruses can cause a variety of diseases, ranging from chickenpox to AIDS. They are not limited to infecting humans; viruses are present everywhere, inhabiting nearly all organisms and thriving in virtually every environment, from the air we breathe to the ocean's deepest depths. Viruses are considered non-living inactive and do not exhibit any characteristics of life when outside a host cell because: (i) They cannot carry out metabolic processes independently. (ii) They lack the genetic information. (iii) They lack a cellular structure (iv) They cannot reproduce on their own.

1. (i) and (ii)
2. (ii), (iii), (iv)
3. (i), (iii), (iv)
4. (ii) and (iv)

Answer: (c) (i), (iii), (iv)