Science
(a) Name the parts of a bisexual flower that are not directly involved in reproduction.
(b) Differentiate between self pollination and cross pollination. List any two significance of pollination.
(c) What is the fate of ovules and ovary after fertilization in a flower?
Answer
(a) Calyx and corolla are the parts of a bisexual flower that are not directly involved in reproduction. Calyx has a protective function while corolla attracts pollinators.
(b)
| Self pollination | Cross pollination |
|---|---|
| Self pollination occurs within a flower or between two flowers of the same plant. | Cross pollination occurs between two flowers of different plants of the same species. |
| No external agent of pollination is required. | External agents such as wind, water, insects, birds and animals are required. |
Significance of pollination — Two significance of pollination are:
- It helps in the production of fruits and seeds.
- It helps in the transfer of characters and traits from both the parents to the offspring.
(c) Ovules mature to form seed and ovary grows to form fruit.
Related Questions
A saturated organic compound 'A' belongs to the homologous series of alcohols.
On heating 'A' with concentrated sulphuric acid at 443 K, it forms an unsaturated compound 'B' with molecular mass 28 u.
The compound 'B' on addition of one mole of hydrogen in the presence of Nickel, changes to a saturated hydrocarbon 'C'.
(i) Identify A, B and C.
(ii) Write the chemical equations showing the conversion of A into B.
(iii) What happens when compound C undergoes combustion ?
(iv) State one industrial application of hydrogenation reaction.
(v) Name the products formed when compound A reacts with sodium.
(i) With the help of a diagram, show the formation of micelles, when soap is applied on oily dirt.
(ii) Take two test tubes X and Y with 10 mL of hard water in each.
In test tube 'X', add few drops of soap solution and in test tube 'Y' add a few drops of detergent solution. Shake both the test tubes for the same period.
(1) In which test tube the formation of foam will be more ? Why ?
(2) In which test tube is a curdy solid formed ? Why ?
(a) An electric iron consumes energy at a rate of 880 W when heating is at the maximum rate and 330 W when the heating is at the minimum. If the source voltage is 220 V, calculate the current and resistance in each case.
(b) What is heating effect of electric current ?
(c) Find an expression for the amount of heat produced when a current passes through a resistor for some time.
Almost all metals combine with oxygen to form metal oxides. Metal oxides are generally basic in nature. But some metal oxides show both basic as well as acidic behaviour. Different metals show different reactivities towards oxygen. Some react vigorously while some do not react at all.
(a) What happens when copper is heated in air ? (Give the equation of the reaction involved).
(b) Why are some metal oxides categorized as amphoteric ? Give one example.
(c) Complete the following equations :
(i) Na2O(s) + H2O(l) ⟶
(ii) Al2O3 + 2NaOH ⟶
OR
(c) On burning Sulphur in oxygen a colourless gas is produced.
(i) Write chemical equation for the reaction.
(ii) Name the gas formed.
(iii) State the nature of the gas.
(iv) What will be the action of this on a dry litmus paper ?