Tag: biology

Questions Related to biology

Which of the following substances are produced by the body cells to protect uninfected cells from viral invasion ?

  1. Histamine

  2. Complement

  3. Natural killer cells

  4. Interferons


Correct Option: D
Explanation:

Interferons (IFNs) are a group of signaling proteins made and released by host cells in response to the presence of several viruses. In a typical scenario, a virus-infected cell will release interferons causing nearby cells to heighten their anti-viral defenses. Interferons are a group of proteins called cytokines produced by white blood cells, fibroblasts, or T-cells as part of an immune response to a viral infection or other immune trigger. The name of the proteins comes from their ability to interfere with the production of new virus particles.


So, the correct option is 'Option D'.

Interferons are produced in response to antigens

  1. True

  2. False


Correct Option: B
Explanation:

Interferon was named for its ability to interfere with viral proliferation. The various forms of interferon are the body’s most rapidly produced and important defense against viruses. Interferons can also combat bacterial and parasitic infections, inhibit cell division, and promote or impede the differentiation of cells. They are produced by all vertebrate animals and possibly by some invertebrates as well.

Interferons are categorized as cytokines, small proteins that are involved in intercellular signaling. Interferon is secreted by cells in response to stimulation by a virus or other foreign substance, but it does not directly inhibit the virus’s multiplication. Rather, it stimulates the infected cells and those nearby to produce proteins that prevent the virus from replicating within them.

So, the correct option is 'False'.

Read the following statements and select the option which identify the incorrect ones:
(i) Potato spindle tuber disease and Chrysanthemum stunt disease are caused by viroids.
(ii) $T _4$ bacteriophage exhibits lytic cycle.
(iii) Retroviruses have two copies of ssRNA.
(iv) Interferon which prevent viral multiplication are glycolipid particles.

  1. (ii) and (iii)

  2. (i) and (iv)

  3. (iii) only

  4. (iv) only


Correct Option: D
Explanation:

Interferons are a group of proteins called cytokines produced by WBC, fibroblasts, or T-cells as part of an immune response to a viral infection or other immune triggers. Interferons are proteinaceous in nature but not glycolipid in nature, thus interferon which prevents viral multiplication are protein particles.

So, the correct option is 'Interferon which prevents viral multiplication are glycolipid particles.'.

Against which of the following does interferon act?

  1. Bacteria

  2. Virus

  3. Snake venom

  4. None of the above


Correct Option: B
Explanation:

Interferons are a group of signaling proteins made and released by host cells in response to the presence of pathogens, such as viruses, bacteria, parasites, or tumour cells. They are a group of glycoproteins, produced by the immune system, that prevent viral replication in infected cells.

Therefore, the correct answer is option A and B.

How many ATP molecule are required in regeneration step for regeneration of $5$ molecule of RuBP in $C _3$ cycle?

  1. $10$

  2. $2$

  3. $4$

  4. $5$


Correct Option: A

Na is an essential element for ....

  1. C3 plant

  2. C4 plant

  3. both (a) and (b)

  4. none of these


Correct Option: A

C-4 plants show poor rate of photosynthesis at low temperature due to __________.

  1. PEPcase

  2. Kranzanatomy

  3. PPDK

  4. Rubisco


Correct Option: A

Which one is false about Kranz anatomy?

  1. It is found in Atriplex

  2. Bundle sheath cells have large chloroplasts and less developed grana

  3. Mesophyll cells have large chloroplasts and more developed grana

  4. The plants with Kranz anatomy have better photosynthetic power than $C _3$ plants.


Correct Option: C

In how many of the given plants $C _{3}$ cycle is present in mesophyll cell?
Wheat, Pea, Maize, Pineapple, Agave, Sorghum, Tomato.

  1. Seven

  2. Five

  3. Six

  4. Two


Correct Option: A

Consider the following families.
a. Amaranthaceae
b. Cyperaceae
c. Euphorbiaceae
d. Nyctaginaceae
Which of these families have plants with $C _4$ metabolism of photosynthesis?

  1. $1$ and $3$

  2. $1, 2$ and $4$

  3. $2, 3$ and $4$

  4. $1, 2, 3$ and $4$


Correct Option: A