| Assertion (A): | It is important that the organisms should have cells. |
| Reason (R): | A cell keeps its chemical composition steady within its boundary. |
| 1. | Both (A) and (R) are true and (R) is the correct explanation of (A). |
| 2. | Both (A) and (R) are true but (R) is not the correct explanation of (A). |
| 3. | (A) is true but (R) is false. |
| 4. | Both (A) and (R) are false. |
| Statement I: | In 1838, Matthias Schleiden, a German botanist, examined a large number of plants and observed that the presence of cell wall is a unique character of the plant cells. |
| Statement II: | In 1839, Theodor Schwann, a British Zoologist, studied different types of animal cells and reported that cells had a thin outer layer which is today known as the ‘plasma membrane’. |
| 1. | Statement I is correct; Statement II is correct |
| 2. | Statement I is correct; Statement II is incorrect |
| 3. | Statement I is incorrect; Statement II is correct |
| 4. | Statement I is incorrect; Statement II is incorrect |
| I: | All cells arise from pre-existing cells. |
| II: | Prokaryotic cells do not have any organelles. |
| III: | Eukaryotic cells have only membrane bound organelle. |
| IV: | Centrosome helps in cell division in plants and animals. |
| Statement I: | Rudolph Virchow proved that all life comes from pre-existing life. |
| Statement II: | Louis Pasteur proved that all cells arise from pre-existing cells |
| 1. | in the cytoplasm |
| 2. | within the chloroplasts (in plants) |
| 3. | within the mitochondria |
| 4. | within the rough ER. |
| I: | Several ribosomes may attach to a single mRNA and form a chain called polyribosomes or polysome. |
| II: | The ribosomes of a polysome translate the mRNA into different proteins. |
| 1. | Only I | 2. | Only II |
| 3. | Both I and II | 4. | Neither I nor II |
| I: | The main chromosomal DNA is linear |
| II: | Plasmid DNA is circular |
| Statement I: | Besides flagella, Pili and Fimbriae are also surface structures of the bacteria but do not play a role in motility. |
| Statement II: | Pili and fimbriae help attach the bacteria to rocks in streams and also to the host tissues. |
| 1. | Statement I is correct; Statement II is correct |
| 2. | Statement I is correct; Statement II is incorrect |
| 3. | Statement I is incorrect; Statement II is correct |
| 4. | Statement I is incorrect; Statement II is incorrect |
Identify the correct statement regarding the part of a cell, the structure of which is shown in the given diagram:
| 1. | It is not found in the plant cells |
| 2. | It serves to provide an attachment with a surface for a bacterial cell |
| 3. | The structure is made of a protein called flagellin |
| 4. | It can be used for movement by a eukaryotic cell |