Biology
The given diagram shows a stage during mitotic division in an animal cell:
(i) Identify the stage. Give a reason to support your answer.
(ii) Draw a neat labelled diagram of the cell as it would appear in the next stage. Name the stage.
(iii) In what two ways is mitotic division in an animal cell different from the mitotic division in a plant cell?
(iv) Name the type of cell division that occurs during:
A. Growth of a shoot
B. Formation of pollen grains
Answer
(i) Prophase.
Chromosomes have duplicated as paired chromatids connected by centromere. Centrosome split into centrioles and are moving to opposite poles. Nuclear membrane and nucleolus disappearing.
(ii) The next stage is Metaphase. It's diagram is shown below:
(iii) Two differences between mitotic division in an animal cell and plant cell are:
| Animal cell | Plant cell |
|---|---|
| Asters are formed. | Asters are not formed. |
| Cytokinesis by formation of furrow in the cytoplasm. | Cytokinesis by cell plate formation. |
(iv) Type of cell division is mentioned below:
A. Mitosis
B. Meiosis
Related Questions
Give the Biological / technical term for the following:
(i) Complete stoppage of menstrual cycle in females.
(ii) Pigment providing colour to urine.
(iii) The vein which drains the blood from the intestine to the liver.
(iv) The canal through which the testes descend into the scrotum just before the birth of a male baby.
(v) The process causing an undesirable change in the environment.
(vi) The removal of nitrogenous wastes from the body.
(vii) The repeating components of each DNA strand lengthwise.
(viii) An alteration in the genetic material that can be inherited.
(ix) The process of uptake of mineral ions against the concentration gradient using energy from the cell.
(x) Blood vessels carrying blood to the left atrium.
Give scientific reasons for the following statements:
(i) Colour blindness is more common in men than in women.
(ii) Injury to medulla oblongata leads to death.
(iii) When an ovum gets fertilized, menstrual cycle stops temporarily in a woman.
(iv) Mature erythrocytes in humans lack nucleus and mitochondria.
(v) Blood flows in arteries in spurts and is under pressure.
The diagram given below is that of a developing human foetus. Study the diagram and then answer the questions that follow:
(i) Label the parts numbered 1 to 3 in the diagram.
(ii) Mention any two functions of the part labelled 2 in the diagram.
(iii) Explain the significance of the part numbered 3 in the diagram.
(iv) Define the term 'Gestation'. What is the normal gestational period of the developing human embryo?
(v) Mention the sex chromosomes in a male and female embryo.
(i) Draw a well labelled diagram of the membranous labyrinth found in the inner ear.
(ii) Based on the diagram drawn above in (i) give a suitable term for each of the following descriptions:
The sensory cells that helps in hearing.
The part that is responsible for static balance of the body.
The membrane covered opening that connects the middle ear to the inner ear.
The fluid present in the middle chamber of cochlea.
The structure that maintains dynamic equilibrium of the body.