Viruses

Q.

How do viruses differ from other mocro-organisms such as bacteria ?

Q.

Assertion [A] Viruses are considered to be at the borderline of living and non-living things.

Reason [R] Viruses cannot survive outside the host organism.

1. Assertion [A] is True and Reason [R] is False

2. Reason [R] is True and Assertion [A] is False

3. Assertion [A] is True and Reason [R] is True and is a correct explanation for [A].

4. Assertion [A] is True and Reason [R] is True but is an incorrect explanation to [A].

Q.

Which of the following is true for a virus?

1. Unicellular

2. Multicellular

3. Acellular

4. Prokaryotic

Q. What is AIDS? Name the causative organism for AIDS. Write any one medium through which the virus is transmitted. [3 MARKS]

Q.

Viruses are acellular

1. Smallpox

2. Common cold

Q.

Question 22
Observe the Fig.2.1 and answer the questions that follows.


(a) Write the name of the disease

(b) Name the causative agent of this disease?

(c) How does the disease spread from one plant to another?

(d) Name any two plant diseases and the microbes that cause them.

Q.

Name any two human diseases caused by viruses.

Q.

At what temperature do most bacteria die?

Q.

What is the meaning of polyhedral virus?

Q.

What is the name of micro-organisms which reproduce only inside the living cells of other organisms ?

Q.

The micro-organisums which can reproduce and multiply only inside the cells of other organisms are :

(a) protozoa (b) fungi (c) bacteria (d) viruses

Q.

Which of the following is NOT a characteristic of a virus?

1. Viruses are acellular

2. Viruses have only a protein coat and genetic material

3. Viruses have a unique cell wall

4. Viruses can live only in a living cell

Q.

AIDS disease is caused by :

(a) bacteria (b) virus (c) worms (d) protozoa

Q.

Describe helical viruses.

Q.

Write the name of the virus which causes AIDS disease.

Q. What is meant by characteristics of bacterial cells?

Q.

Which of the following statement(s) is/are true about viruses?

i. Viruses are smaller than the bacteria

ii. Viruses are active outside the host cell

iii. Viruses use the host cell to reproduce

iv. Viruses do not contain DNA or RNA

1. i

2. iii and iv

3. i and iii

4. ii and iv

Q.

Viruses are assigned to the kingdom ___ .

1. Protista

2. Fungi

3. None of the above

4. Monera

Q. Sunil ate 'pani-puri' with his friends. He started getting stomach ache, diarrhoea, weakness and loss of appetite. He is likely to be suffering from which of the following disease?

1. Tuberculosis
2. Malaria
3. Typhoid
4. Ringworm

Q.

Name two viral disease of plants.

Q.

With respect to the given statements, choose the correct option.
Statement 1: Viruses are inactive when they are outside the host body.
Statement 2: Viruses do not have a cellular organisation.

1. Only statement 1 is correct

2. Only statement 2 is correct

3. Both the statements are incorrect

4. Both the statements are correct

Q.

Immunodeficiency syndrome develops in the disease called ___.

Q.

Which of the following organisms have only a protein coat and the genetic material?

1. Bacteria

2. Viruses

3. Amoeba

4. All of the above

Q.

List some properties of viruses.

Q. The image shows the okra (bhindi) plant with the yellow vein mosaic disease.

1. True
2. False

Q.

Which of the following can be made into crystals?

1. Bacteria

2. Fungi

3. Virus

4. Protozoa

Q. Which of the following is incorrect about viruses?

1. Viruses have either DNA or RNA as the genetic material.
2. Viruses do not infect bacteria, fungi, and algae.
3. Viruses use host machinery to produce more of their kind.
4. Viruses are useful in the preparation of vaccines.

Q.

The disease rust of wheat in plants is caused by bacteria.

1. True

2. False

Q. Bacteriophage is an example of _________.

1. an algae
2. a bacteria
3. a fungi
4. a virus

Q.

Viruses that infect bacteria are called ___.