Reproduction in Plants Notes 2024-25 PDF

**[REPRODUCTION IN PLANTS ]** 1.How does the process of fertilization take place in flowers? Ans: When pollen lands on stigma, it germinates and gives rise to a pollen tube that passes through the style and reaches the ovary of a pistil. When the pollen tube reaches an ovule, it releases the male...

**[REPRODUCTION IN PLANTS ]** 1.How does the process of fertilization take place in flowers? Ans: When pollen lands on stigma, it germinates and gives rise to a pollen tube that passes through the style and reaches the ovary of a pistil. When the pollen tube reaches an ovule, it releases the male gametes. A male gamete fuses with a female gamete in the ovule. This process is known as fertilization. The cell which is formed after the fusion of a male and a female gamete is known as zygote. This zygote divides several times in order to form the embryo present inside the seed. 2.Describe the technique of grafting. How is it different from the technique of layering? Ans: Grafting is a method in which two plants are joined together in such a way that two stems join and grow as a single plant. The plant which is attached to soil is called stock and the cut stem of another plant without the roots is called scion. This technique is very useful in propagating improved varieties of various flowers and fruits.Examples: mango, Apple, citrus fruits, etc. Layering is a method in which a branch of the plant with at least one node is bent towards the ground and a part of it is covered with moist soil leaving the tip of the branch exposed above the ground. After some time, new roots develop from the part of the branch buried in the soil. The branch is then cut-off from the parent plant. The part which has developed roots grows to become a new plant. 3\. Coconut is a large and heavy fruit. How is it adapted for dispersal by water? Ans:The seeds of some plants that have an outer fibrous or spongy covering are dispersed through water. They have the ability to float in the water. The coconut fruits have a fibrous outer coat which enables them to float in water and carried away by flowing water to far off places. [CASE BASED QUESTION:] 1.When you keep food items like bread and fruits outside for a long time especially during the rainy season, you will observe a cottony growth on them. \(a) What is this growth called? \(b) How does the growth take place? Ans:(a) When food items like bread and fruits are kept outside for a long time especially during the rainy season, a cottony growth of bread mould, a fungus is observed. \(b) This growth of fungus takes place by spores present in air, which when comes in contact with moisture in bread germinates and grows to produce new cells. [ASSERTION AND REASONING QUESTIONS : (find the answer) ] I. The question below consists of an Assertion and a Reason. Use the following key to choose the appropriate answer. \(a) Both A and R are true and R is the correct explanation of A. \(b) Both A and R are true but R is not the correct explanation of A. \(c) A is true but R is false. \(d) A is false but R is true. 1.**Assertion (A) :** Vegetative propagation is a method of asexual reproduction in plants. **Reason (R) :** In asexual reproduction new plants are obtained without use of seed or spore. 2.**Assertion (A) :** Parts of pistil are anther and filament. **Reason (R) :** Bisexual flowers are those which contain both stamen and pistil.