Tag: life in water

Questions Related to life in water

Raphides are formed of

  1. Calcium oxalate

  2. Calcium carbonate

  3. Sodium chloride

  4. Sodium carbonate


Correct Option: A
Explanation:
  • Minerals crystals are found in plant cell walls in the form of calcium oxalate, carbonate or silica.
  • Calcium oxalate occurs in the form of a mass of crystals around a cellulosic core in few plants.
  • Calcium oxalate crystals occur in the form of needle-shaped in few plant cells and are called raphides.
  • Eg- Water hyacinth.
  • So, the correct answer is 'Calcium oxalate'.

Study of genetic composition of population in relation to habitat is called

  1. Genecology

  2. Genetics

  3. Eugenics

  4. Euthenics


Correct Option: A
Explanation:
a) Genecology is a branch of ecology which studies genetic variation of species compared to their population distribution in a particular environment.
b) Genetics is the branch of zoology which deals with the mechanism of heredity. It deals with transmission of hereditary characters from parents to offspring. 
c) Eugenics is the branch of science which deals with the selection of desired heritable characteristics in order to improve future generations.
d) Euthenics is the science of improving the internal well-being of the human by improving the external factor of their environment. 
So, the correct answer is 'Genecology'.

______ has glandular hair.

  1. Calotropis

  2. Tobacco

  3. Lemon

  4. Yucca


Correct Option: B
Explanation:

There are various defense mechanism seen in plants. These are thorns, spines, prickles, glandular hair, stinging hair, alkaloids, tannins, raphides, etc. Tobacco has glandular hair for its defense. Glandular hair with sticky substances protect it from outer agencies. Lemon has thorns to protect itself from its enemies. Yucca has pointed spines at the leaf ends to protect itself from enemies.
Calotropis is known as milkweeds because of the latex they produce. Thus, the correct answer is 'Tobacco.'

Dry scales of onion possess in their cells

  1. Raphides

  2. Prismatic crystals

  3. Sphaeraphides

  4. Crystal sand


Correct Option: B
Explanation:

A. Calcium oxalate crystals occur in the form of needle-shaped in few plant cells and are called raphides.

  • Eg- Water hyacinth.

B. Calcium oxalate in the form of rod-like or cubicle shaped in few plant cells and are called prismatic crystals.

  • Eg- dry scales of onions.

C. Calcium oxalate crystals occur in the form of star-shape in plant cells and are called sphaeraphides.

  • Eg- phylloclades of Colocasia.

D. Calcium oxalate is deposited in the leaves within the vacuoles during early developmental stages in plants is called crystal sand. Eg- Beet root

So, the correct answer is 'Prismatic crystals'.

Which one of the following plant species is NOT a sand binder in the semi arid region?

  1. Salvadora indica

  2. Calotropis procera

  3. Saccharum munja

  4. Saccharum spontaneum


Correct Option: A

Which one of the following is an example of a plant adapted to highly saline coastal conditions?

  1. Sonneratia acida

  2. Anaardium occidentale

  3. Taxus baccata

  4. Gnetum gemon


Correct Option: A

Which of the following pairs of plant categories and habitat types are correctly matched?
a. Sociophytes- Shady
b. Heliophytes - Sunny
c. Psammophytes - Sandy
Select the correct answer using the codes given.

  1. $1, 2$ and $3$

  2. $1$ and $2$

  3. $1$ and $3$

  4. $2$ and $3$


Correct Option: A

Which one is concerned with the temporary adaptation ?

  1. Phytomelanin

  2. Melanin

  3. Tannin

  4. Anthocyanin


Correct Option: A

In which one of the following geological periods did the first land plants appear?

  1. Precambrian

  2. Permian

  3. Silurian

  4. Carboniferous


Correct Option: A