When a human female reaches a certain age then vaginal bleeding occurs for a few days after regular time intervals.

(a) What is this process known as (i) in scientific terms, and (ii) in everyday language?

(b) At what approximate age this process starts in human females? What is the human female said to have attained at this stage ?

(c) After how much time is this process repeated? For how many days this process usually lasts?

(d) What does the onset of this process in human females signify?

(e) At which particular event in the life of a human female this process stops temporarily but starts again?

(f) At which approximate age of human female this process stops permanently ?

The flask-shaped organ A at the centre of a flower is surrounded by a number of little stalks B having swollen tops which lie just inside the ring of petals.

(a) Name A. What are the various parts of A?

(b) Which part of A contains gametes?

(c) Name B. What is the swollen top of B known as ?

(d) What does the swollen top of B contain ?

(e) Out of A and B, which one is (i) male part, and (ii) female part of the flower?

When an insect sits on the flower of a plant then some particles A present in the top of little stalks in the flower attach to its body hair. When this insect now sits on the flower of another similar plant, then particles A attached to the hair of insect are put on the top of a flask-shaped organ at the centre of flower. The particle A grows a long tube B from the top of flask-shaped organ through which C moves down and reaches the bottom part of flask-shaped organ. Here C fuses with the nucleus of D contained in structure E. The fusion of C and D forms a new cell F which grows and develops into a seed of the plant.

(a) What are particles A ? What is the process of transferring A from one flower to another flower of similar plant by the insect known as ?

(b) What is the name of tube B?

(c) What is C which moves down through the tube B?

(d) Name D and E.

(e) What is F ?

X and Y are two human beings. The organ A in the reproductive system of X releases a mature gamete B once a month which goes into a tube-like structure C through a funnel-like opening. The organ D in the reproductive system of Y makes and releases gametes E which pass through a duct F and are introduced by an organ of Y, into the body of X. B and E fuse together in C to form a new cell G. The cell G divides repeatedly to form a ball of cells H which gets embedded in the lining of organ I of reproductive system of X where it grows and develops into a baby.

(a) Name (i) organ A, and (ii) gamete B.

(b) Write two names of tube-like structure C.

(c) Name (i) organ D, and (ii) gamete E.

(d) Write two names of duct F.

(e) Name (i) cell G (ii) ball of cells H, and (iii) organ I.

(f) Out of X and Y, which one is (i) male, and (ii) female ?

When a fertilised egg E formed in the oviduct of a human female divides repeatedly to form an embryo, the embryo gets implanted in the thick and soft lining of the uterus. After this a disc-like special tissue T develops between the uterus wall and embryo through which all the requirements of the developing embryo (and foetus) are met from the mother's body. The embryo is connected to the tissue T through a string like structure S.

(a) What is the other name of fertilised egg cell E ?

(b) What is the name of tissue T ?

(c) Name the string-like structure S .

(d) Name two substances which pass from mother's blood to embryo through tissue T and, one type of substance which passes from embryo to mother's blood.

(e) What happens to S when the baby is born ? Why ?