Tag: life in water

Questions Related to life in water

Phycology is the study of

  1. Plants

  2. Virus

  3. Algae

  4. Bacteria


Correct Option: A

In submerged hydrophytes, the stems are extremely weak due to

  1. Absence of phloem

  2. Absence of xylem

  3. Presence of aerenchyma

  4. Poor development of xylem and mechanical tissue


Correct Option: D
Explanation:

In submerged hydrophytes, the entire plant body is involved in the absorption of water and these plants not experiences much stress or pressure internally. So in these plants, xylem and mechanical tissues are poorly developed.

So, the correct option is ‘Poor development of xylem and mechanical tissues’.

Finely dissected leaves occur in

  1. Free floating plants

  2. Rooted floating leaved plants

  3. Submerged plants

  4. Emerged plants


Correct Option: C
Explanation:
Finely dissected leaves occur in submerged plants. In submerged plants, the leaves are finely dissected till the midrib. This dissection gives a feather-like appearance. In this, only the stalk of flower remains above the water and rest of the plant is submerged.
Thus, the correct answer is 'Submerged plants.'

Which do not have stomata?

  1. Submerged hydrophytes

  2. Hygrophytes

  3. Mesophytes

  4. Xerophytes


Correct Option: A
Explanation:

A.Submerged hydrophytes – plants grow completely in the water, stomata are absent.

B.Hygrophytes – plants grow in wet conditions, stomata are present.

C.Mesophytes – plants grow in average climatic conditions. Stomata are present.

D.Xerophytes – plants grow in dry or arid conditions, sunken stomata are present.

So, the correct option is ‘submerged hydrophytes’.

Which of the following is considered to be the main adaptation for hydrophytes?

  1. Large leaves

  2. Presence of aerenchyma

  3. Weak root system

  4. Roots with root pocket


Correct Option: B
Explanation:

In hydrophytes or aquatic plants, large intercellular air spaces are developed extensively in the parenchyma so as to form a connected system throughout the plant. Such a modified parenchymatous tissue is called aerenchyma. It provides buoyancy to the plants and helps in gaseous exchange also. Thus the correct answer is option B.

________ seed in which reserve food is present in the perisperm.

  1. Nymphaea

  2. Coconut

  3. Onion

  4. Litchi


Correct Option: A
Explanation:

A. Nymphaea- Reserve food material in perisperm (Persistant nucellus). Perisperm occurs in the seeds of black pepper, coffee, castor, cardamom, Nymphaea. It is diploid.

B. Coconut- Reserve food material in endosperm.

C. Onion- Reserve food material in endosperm

D. Litchi- Reserve food material in cotyledons.

So, the correct answer is 'Nymphaea'.

Stem of submerged hydrophytes is soft and weak, because of

  1. Absence of phloem

  2. Absence of stomata

  3. Absence of xylem

  4. Feebly developed supporting tissue and xylem


Correct Option: D

Submerged hydrophytes have a well developed

  1. Vascular system

  2. Aerenchyma

  3. Root system

  4. Stomatal system


Correct Option: B

Eichhornia crassipes is

  1. Xerophyte

  2. Hydrophyte

  3. Mesophyte

  4. Parasite


Correct Option: B

Which one is partially submerged and fixed in the mud?

  1. Marsilea

  2. Cyperus

  3. Eichhornia

  4. Typha


Correct Option: D