Biology Class 11 NCERT Solutions: Chapter 5 Morphology of Flowering Plants Part 2

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Q: 6. Differentiate between

(A) Racemose and cymose inflorescence

(B) Fibrous roots and adventitious roots

(C) Apocarpous and syncarpous ovary

Answer:

Q_6_1_Table of Racemose and Cymose Inflorescence
Q_6_1_Table of Racemose and Cymose Inflorescence

Racemose Inflorescence

Cymose Inflorescence

(1)

Younger flowers are present at the tip while older flowers are arranged at the base of this inflorescence. Such an arrangement is called acropetal succession.

(1)

Younger flowers are present at the base of the inflorescence, while older flowers are present at the top. Such an arrangement is called basipetal succession.

(2)

The main axis in Racemose inflorescence continues to grow and

produce flowers laterally.

(2)

The main axis in cymose inflorescence has limited growth, which later terminates into a flower.

(3)

Image shows the racemose inflorescence

Image Shows the Racemose Inflorescence

Image shows the racemose inflorescence

(3)

Image shows the cymose inflorescence

Image Shows the Cymose Inflorescence

Image shows the cymose inflorescence

Image shows the Inflorescence

Image Shows the Inflorescence

Image shows the Inflorescence

Q_6_2_Table of Fibrous and Adentitious Root
Q_6_2_Table of Fibrous and Adentitious Root

Fibrous Root

Adventitious Root

(1)

In monocots, the primary root, which develops from the radicle of the seed, is short-lived and is replaced by a large number of roots arising from the base of the stem.

(1)

These roots arise from any part of the plant other than the radicle of seeds.

(2)

It is found in wheat and other cereals.

(2)

It is found in banyan, Monstera, and other plants.

(3)

Image shows the fibrous root

Image Shows the Fibrous Root

Image shows the fibrous root

(3)

Image shows the adventitious root

Image Shows the Adventitious Root

Image shows the adventitious root

Q_6_3_Table of Apocarpous and Syncarpous Ovary
Q_6_3_Table of Apocarpous and Syncarpous Ovary

Apocarpous Ovary

Syncarpous Ovary

(1)

The Flowers with Apocarpous Ovary have more than one carpel. These Carpels are free

(1)

The flowers with syncarpous ovary have more than one carpel. However, these carpels are fused

(2)

It is found in lotus and rose flowers.

(2)

It is found in the flowers of tomato and mustard.

(3)

Image shows the Apocarpous Ovary

Image Shows the Apocarpous Ovary

Image shows the Apocarpous Ovary

(3)

Image shows the Syncarpous Ovary

Image Shows the Syncarpous Ovary

Image shows the Syncarpous Ovary

Q: 7. Draw the labelled diagram of the following:

(i) Gram seed

(ii) V. S. of maize seed

Answer:

(i) Gram seed

Q 7 i Image of Gram Seed

Q 7 I Image of Gram Seed

Q 7 i Image of Gram Seed

(ii) V. S. of maize seed

Q 7 ii Image of V.S. of Maize Seed

Q 7 Ii Image of V.S. Of Maize Seed

Q 7 ii Image of V.S. of Maize Seed

Q: 8. Describe modifications of stem with suitable examples

Answer:

Stems of various plants have undergone modifications to perform different functions.

Underground stems or storage stems:

Examples: Rhizomes, Corms, tubers

Underground stems or storage stems

Underground Stems or Storage Stems

Underground stems or storage stems

In ginger and banana, the underground stem is called a rhizome. The underground stem in Colocasia (arbi) is known as corm. Rhizomes and corms are underground stems, modified for the storage of food. Also, these stems help in vegetative reproduction of these plants. The tips of the underground stem in potato plants become swollen due to the accumulation of food. The potato is a tuber that helps in the storage of food and bears eyes on it. Subtended by a leaf scar, these eyes bear buds that give rise to new plants.

Supportive stems

Example: tendril

Image of Supportive stems

Image of Supportive Stems

Image of Supportive stems

The stem in some weak plants bear thin, slender, and spirally-coiled structures called tendrils that help the plant get attached to nearby structures for support. Tendrils are found in cucumbers, melons, and other members of the family Cucurbitaceous.

Protective stems

Example: Thorns

Image shows the Protective stems

Image Shows the Protective Stems

Image shows the Protective stems

The stem in bougainvillea and citrus plants (like lemon and orange) bear sharp, pointed structures called thorns, which provide protection to the plant from herbivores.

Photosynthetic stems

Example: Opuntia

The stem in the Opuntia is green. It carries out the process of photosynthesis in the absence of leaves.

Others stem modifications

In some plants, underground stems such as grasses spread in the soil and help in perenation. These stems are called runners.

The short lateral stem called the offset in some aquatic plants (such as Eichhornia) bears leaves and tufts of roots at the node and gives rise to new plants.