1. Name the plant organ which grows towards gravity and water but away from light?

Ans. Root.

2. From which part of the germinating seed does the root develop?

Ans. Radicle.

3. Why root system gives better anchorage and why?

Ans. The tap root system gives better anchorage as it is very deep-seated branches profusely, ramify through big areas in soil.

4. Give two examples each of plants having fibrous and tap root system.

Ans. (i) The fibrous root system in maize and sugarcane. 

(ii) Tap root system in sunflower and mango.

5. Mention three characters by which you can say that carrot which you eat is a root.

Ans. The absence of nodes, internodes, buds and leaves.

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1. Name the structure which protects the root apical meristem.

Ans. Root cap.

2. Give in a sequence, the various regions of root from its tip towards its base.

Ans. (i) Root cap region.

(ii) region of meristematic cells.

(iii) region of elongation.

(iv) region of maturation.

3. Into which tissues do dermatogen and plerome differentiate?

Ans. Dermatogen differentiates into epiblema and cap, but plerome differentiates into stele.

4. Which region of root absorbs water and mineral salts?

Ans. Root hair or piliferous region.

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1. Are carrot, radish and turnip roots? Justify. Why have they become fleshy?

Ans. Yes. They are roots as they are without nodes and internodes, buds or leaves. They become fleshy for storage of food.

2. Name the type of root modification found in plants growing in marshy areas. What is their function? 

Ans. Pneumatophore; respiration.

3. What is the tissue in aerial roots of epiphytes known as which helps in absorp-tion of moisture from the atmosphere?

Ans. Velamen.

4. What are the two main functions of roots? 

Ans. (i) Anchorage.

(ii) Absorption of water and the minerals.

5. Match the items of column A with those in column B

Ans. 

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1. Name the condition where protoxylem lies towards the periphery and metaxylem towards centre.

Ans. Exarch.

2. Why is it difficult to pluck lateral roots from carrot?

Ans. As they arise from inner layer that is origin

pericycle or they are endogenous in origin.

3. What is the seat of origin of lateral roots and cambium?

Ans. Pericycle.

4. Name the endodermal cells which do not possess casparian strips and help in the movement of water.

Ans. Passage cells.

5. Give two major differences between dicot and monocot root.

Ans. Two Major differences between Dicot Root and Monocot Root:

6. If the number of xylem bundles is 4 (tetrarch), how many lateral roots will be formed in that area?

Ans. Four.

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1. Name the lateral meristem found in old dicot roots. What is their function?

Ans. Vascular cambium and cork cambium. The vascular cambium forms secondary vascular tissue. But the cork cambium forms cork and secondary cortex.

2. From which layer does the vascular cambium originate?

Ans. Pericycle and conjunctive tissue.

3. What is conjunctive tissue?

Ans. Conjunctive tissue: It is the “paren-chyma tissue lying between xylem and phloem patches that are arranged radially in roots.”

4. Define periderm. What role does it play in a root?

Ans. Periderm is a tissue “which is formed during secondary growth and consists of phellem, phellogen and phelloderm; protection.

5. Do primary roots of dicot plant possess cambium?

Ans. No, the cambium is absent in primary dicot root.