Science (English Medium) इयत्ता ११ - CBSE Question Bank Solutions for Biology

The body of sponges does not possess tissue level of organisation though it is made of thousands of cells. Comment.

Stratified epithelial cells have limited role in secretion. Justify their role in our skin.

How does a gap junction facilitate intercellular communication?

Write the appropriate type of tissues in column B according to the functions mentioned in column A.

Classify and describe epithelial tissue on the basis of structural modifications of cells.

Is rubber a primary metabolite or a secondary metabolite? Write four sentences about rubber.

Mitosis is characterised by ______.

Cells which are not dividing are likely to be at ______.

Between a prokaryote and a eukaryote, which cell has a shorter cell division time?

Which of the phases of cell cycle is of longest duration?

Which tissue of animals and plants exhibits meiosis?

Which part of the human body should one use to demonstrate stages in mitosis?

It is said that the one cycle of cell division in human cells (eukaryotic cells) takes 24 hours. Which phase of the cycle, do you think occupies the maximum part of cell cycle?

Label the diagram and also determine the stage at which this structure is visible.

While examining the mitotic stage in a tissue, one finds some cells with 16 chromosomes and some with 32 chromosomes. What possible reasons could you assign to this difference in chromosome number. Do you think cells with 16 chromosomes could have arisen from cells with 32 chromosomes or vice versa?

Mitosis results in producing two cells which are similar to each other. What would be the consequence if the following irregularities occur during mitosis?

Duplication of DNA does not occur

Two key events take place, during S phase in animal cells, DNA replication and duplication of centriole. In which parts of the cell do events occur?

Comment on the statement – Telophase is reverse of prophase.

Carefully observe the following figure

1. Name the technique shown in the figure and the scientist who demonstrated this technique for the first time.
2. Name atleast three plants for which this technique can be employed for their commercial production.
3. What is the significance of aerating tube and feeding funnel in this setup?

Hydroponics have been shown to be a successful technique for growing of plants. Yet most of the crops are still grown on land. Why?