ADDITIONAL QUESTIONS :.
(a) Give reason for each of the following :
(i) Anthers of angiospermic flowers are described as dithecous.
(ii) Hybrid seeds have to be produced year after year.

ADDITIONAL QUESTIONS : The diagram represents a flower. Label the parts and answer the following : (a) Give the letter of the structure which : (i) becomes the fruit wall, (ii) becomes the testa (seed coat), (iii) produces pollen grains. (b) Explain two ways, shown in the diagram, in which this flower is adapted for insect pollination.

Long Answer Questions Five mark Each QUESTIONS FROM CBSE BOARD EXAMINATIONS : Give reasons why : (i) most zygotes in angiosperms divide only after certain amount of endosperm is formed. (ii) groundnut seeds are exalbuminous and castor seeds are albuminous. (iii) micropyle remains as a small pore in the seed coat of a seed. (iv) integuments of an ovule harden and the water content is highly reduced as the seed matures. (v) apple and cashew are not called true fruits.

ADDITIONAL QUESTIONS : The diagram below shows a germinating pollen grain and a mature ovule from an insect-pollinated flower. Some parts have been labelled. Give the letter of the nucleus which fuses with a male nucleus to form each of the following : (i) The zygote (ii) The endosperm

The following graph is another historam (Fig.) From the bars of this histogram, we can answer the following questions : (i) How many teachers are of age 45 years or more but less than 50 years? (ii) How many teachers are of age less than 35 years?

Long Answer Questions Five mark Each QUESTIONS FROM CBSE BOARD EXAMINATIONS : Fertilization is essential for production of seed, but in some angiosperms seeds develop without fertilization. (i) Give an example of an angiosperm that produces seeds without fertilization. Name the process. (ii) Explain the two ways by which seeds develop without fertilization.

ASSERTION TYPE QUESTIONS : These questions consist of two statements each, printed as Assertion and Reason. While answering these questions, you are required to choose any one of the following four responses. A. If both Assertion and Reason are true and Reason is correct explanation of Assertion. B. If both Assertion and Reason are true but Reason is not correct explanation of Assertion. C. If Assertion is true but Reason is false. D. If both Assertion and Reason are false. . Assertion : Protandry is a condition in which anthers mature earlier than stigma. Reason : Cleistogamous flowers are bisexual and never open.

Long Answer Questions Five mark Each QUESTIONS FROM CBSE BOARD EXAMINATIONS : (a) Draw a diagrammatic sectional view of a mature anatropous ovule and label the following parts in it: (i) that develops into seed coat. (ii) that develops into an embryo after fertilization. (iii) that develops into an endosperm in an albuminous seed. (iv) through which the pollen tube gains entry into the embryo sac. (v) that attaches the ovule to the placenta (b) Describe the characteristic features of wind pollinated flowers.

Long Answer Questions Five mark Each QUESTIONS FROM STATE BOARD EXAMINATIONS : Three different flowers are given to you in the practical class: (i) Maize (ii) Vallisneria (iii) Rose You are asked to group them on pollinating agents. Describe the adaptations of each flower related with agents of pollination.

Long Answer Questions Five mark Each QUESTIONS FROM CBSE BOARD EXAMINATIONS : A flower of tomato plant following the process of sexual reproduction produces 240 viable seeds. Answer the following questions giving reasons: (a) What is the minimum number of pollen grains that must have been involved in the pollination of its pistil? (b) What would have been the minimum number of ovules present in the ovary? (c) How many megaspore mother cells were involved? (d) What is the minimum number of microspore mother cells involved in the above case? (e) How many male gametes were involved in this case?