Biology
Given below are diagrams showing the different stages in the process of fertilisation of an egg in the human female reproductive tract.
Study the diagrams and answer the questions:
(i) Arrange the letters given below each diagram in a logical sequence to show the correct order in the process of fertilisation.
(ii) Where does fertilisation normally take place? What is 'Implantation' that follows fertilisation?
(iii) Mention the chromosome number of the egg and zygote in humans.
(iv) Explain the term 'Gestation'. How long does Gestation last in humans?
(v) Draw a neat, labelled diagram of a mature human sperm.
Answer
(i) DCBA (It can also be CBAD as there is not a clear difference between egg cell and zygote)
(ii) Fertilization usually takes place in fallopian tube (oviduct) that links an ovary to the uterus. The process of fixing of the blastocyst to the wall of the uterus/endometrium is termed implantation.
(iii) Chromosome number of the egg is 23 and zygote is 46 / 23 pairs.
(iv) The period of full term development of the embryo in the uterus. This period lasts for 280 days. It is the period between implantation and birth of baby.
(v) Labelled diagram of a mature human sperm is shown below:
Related Questions
The diagram given below represents a stage during cell division. Study the same and answer the questions that follow:
(i) Identify whether it is a plant cell or an animal cell. Give a reason in support of your answer.
(ii) Name the stage depicted in the diagram. What is the unique feature observed in this stage?
(iii) Name the type of cell division that occurs during:
- Replacement of old leaves by new ones.
- Formation of gametes.
(iv) What is the stage that comes before the stage shown in the diagram?
(v) Draw a neat, labelled diagram of the stage mentioned in (iv) above keeping the chromosome number constant.
Mention the exact location of the following:
(i) Epididymis
(ii) Lacrimal gland
(iii) Malleus
(iv) Hydathodes
(v) Pulmonary semilunar valve
A potted plant with variegated leaves was taken in order to prove a factor necessary for photosynthesis. The potted plant was kept in the dark for 24 hours and then placed in bright sunlight for a few hours. Observe the diagrams and answer the questions.
(i) What aspect of photosynthesis is being tested in the above diagram?
(ii) Represent the process of photosynthesis in the form of a balanced equation.
(iii) Why was the plant kept in the dark before beginning the experiment?
(iv) What will be the result of the starch test performed on leaf 'A' shown in the diagram? Give an example of a plant with variegated leaves.
(v) Draw a neat labelled diagram of a chloroplast.
The diagram given below shows the internal structure of a spinal cord depicting a phenomenon. Study the diagram and answer the questions:
(i) Name the phenomenon that is depicted in the diagram. Define the phenomenon.
(ii) Give the technical term for the point of contact between the two nerve cells.
(iii) Name the parts numbered 1, 2 and 3.
(iv) How does the arrangement of neurons in the spinal cord differ from that of the brain?
(v) Mention two ways by which the spinal cord is protected in our body.