You must have seen your mother adding 3-4 globules of yeast to the idli paste she has prepared.  Similarly, brewing industry uses yeast in the manufacture of alcohol.
(a) How does such a small amount of yeast added help to produce thousands of litres of alcohol? Explain how yeast multiples so fast.
(b) Name the process carried out by yeast in these cases.
(c) What value is learnt from these?

A farmer cultivates sugar cane and rose by usin stem cuttings.  He found that some of the cuttings did not continue to grow into new plants.  As a student of Agriculture; Shanu gives some points to be followed.
(a) Can you suggest a reason for this?
(b) Enlist the aspects that Shanu must have given for consideration, while preparing stem cuttings for propagation.
(c) Name two other plants which are also propagated by stem cuttings.
(d) What value (s) is/are shown by Shanu?

Jagan has two mango trees in the backyard  of his house, which yielded fruits for the first time during this summer.  The fruits were small, fibrous and not so sweet.  In the next house, where his friend Ajay livers, there is a mango tree, which yields fruits that are fleshy/juicy, very sweet and bigger in size.  Ajay, a student of B.sc. (Botany) comes out with an idea and takes some branches from the jagan's garden to his garden and explains the procedure.
(a) What method do you think Ajay has suggested for getting good quality fruits, on the trees of Jagan's house in a short period of time, i.e. during the next season?
(b) Describe how it is carried out to help japan.
(c) What are its advantages over growing a mango tree with the seeds obtained from Ajay's garden?
(d) Mention the values expressed by Ajay in this case.

In nature, i,e in the wild, birds lay eggs seasonally during a particular time of the year, but in a poultry farm, eggs are produced throughout the year.
(a) Give reason for this observation.    
(b) Is it ethically/morally correct in your opinion? Justiy your argument.

Although sexual Reproduction is a long drawn, energy intensive complex from of reproduction, many groups of organisms in Kindom Animalia and Plantae prefer this mode of reproduction. Give atleast three reasons for this.

Difference between:
(a) Oestrous cycle and menstrual cycle
(b) Ovipary and vivipary. City an example of each type .

Rose plants produce large, attractive bisexual flowers but they seldom produce fruits. On the other hand Lady's finger produces plenty of fruits. Analyse the reasons for failure of fruit formation in rose.

Rachna's father went to Kolkata where he was gifted a pot with new variety of rose. The flowers were very beautiful. On birthday of Rachna's father to bring for her the same variety of rose on his next visit to Kolkata. He smiled and advised her to raise it herself from the plants growing in his home.
Read the above passage and answer the following question:
(i)   How can father's advice help Neena to raise new seedling of rose variety present in Ranchna's home?
(ii)  Which method of reproduction is involved in this process?
(iii) Can this technique be used for commercial propagation of other ornamental plants?

Last year, Dadaji was going to meet his old friend in a village near Lucknow. Dadaji's friend was earnings a lot by exporting mangoes. Anil also accompanied Dadaji as he also very found of mangoes. Dadaji's friend invited him to visit the orchard. Anil knew that there are many varieties of mangoes with different shapes, color of skin and tastes. On visiting the orchard, Anil was surprised to see that more than one type of mangoes were growing on the same tree.
(i) Is it possible for Anil to grow for commercial purpose any variety of mango on the tree of mango growing in his garden?
(ii) What type of reproduction is involved in this process?
(iii) Name any other species which can be propagated by this technique for commercial purpose.
(iv) How could Dadaji's friend improve the varieties of mangoes in his garden?