Tag: root system in plants

Questions Related to root system in plants

Plants living perched on other plants but not obtaining water or food from them are called

botany root - external morphology root system in plants modifications of root root modifications

  1. Hydrophytes

  2. Periphytes

  3. Epiphytes

  4. Epinastic plants

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Correct Option: C
Explanation:
These stems will supply water to the plants when there is not enough rain water.  Some epiphytes, like certain orchids, have roots that can absorb water vapour from the air! For their nutrients (something like vitamins), these epiphytes get them from rotting leaves, twigs and small branches that are found nearby. So, the correct answer is "Epiphytes."

Choose the correct answers from the alternatives given.
Unlike primary growth, secondary growth in both roots and stems

botany root - external morphology root system in plants modifications of root root modifications

  1. Is indeterminate

  2. Produces xylem and phloem

  3. Involves vascular and cork cambiums

  4. Result in a rapid increase in root or stem length

Show answer
Correct Option: C
Explanation:

Secondary growth is the increase in the girth of stem and roots of plant. It occurs by cell divisions in two lateral meristems that are vascular cambium and cork cambium.

Vascular cambium is a thin layer of cells between xylem and phloem which increases girth by cell divisions
Cork cambium is a layer of meristematic cells that give rise to cork outside and secondary cortical cells inside.
While plant growth is indeterminate due to both primary and secondary growth. Also, both primary and secondary produce xylem and phloem. 
So the correct answer is it "Involves vascular and cork cambiums''

Velamen is found in

botany root - external morphology root system in plants modifications of root root modifications

  1. Vanda

  2. Rosa

  3. Viscum

  4. Sanctalum

Show answer
Correct Option: A
Explanation:

Velamen is the thick layer of dead cells that covers the aerial roots of certain orchids and aroids and absorbs moisture from the surroundings. Vanda is an example of a genus having velamen in their roots from orchid family.

So, the correct option is 'Vanda'.

Rema was in the biology lab. When observing a plant tissue under the microscope, she saw a small out-growth coming from the outermost layer. Which part did she identify?

botany root - external morphology morphology of the root root system in plants root

  1. Trichomes

  2. Flower buds

  3. Stomata

  4. Leaves

Show answer
Correct Option: A
Explanation:

Rema observed trichomes which are considered to be the outgrowth from the epidermis of the plant and are unicellular and mostly glandular. It helps in the absorption of water and minerals.

So, the correct answer is 'Trichomes'.

A root grows in length,which region of the root is responsible for this growth?

botany root - external morphology morphology of the root root system in plants root

  1. Root cap

  2. Region of meristematic activity

  3. Region of elongation

  4. Region of maturation

Show answer
Correct Option: C
Explanation:

A)The root is covered at the apex by a thimble-like structure called the root cap that protects it from damage.

B)The cells are thin-walled and with dense protoplasm and divide rapidly forms region of meristematic activity.
C)The cells that divide undergo rapid elongation and are responsible for the growth of the root length is the region of elongation.
D)The cells of elongation gradually differentiate and mature is called the region of maturation.
So the correct option is ' Region of elongation'.

Roots and shoots lengthen through the activity of

botany root - external morphology morphology of the root root system in plants root

  1. Apical meristem

  2. Vascular Cambium

  3. Lateral meristem

  4. Cork Cambium

Show answer
Correct Option: A
Explanation:
Apical meristem is found at the growing tips, that is root and shoot tips. These are actively dividing cells and are thus responsible for the growth of plant lengthwise. Shoot apical meristem occurs at the apex of the shoot which allows the shoot to elongate. Root apical meristem occurs at the apex of the root which allows the root to elongate. Rapid division of meristematic cells can cause the plant to grow tall.
Thus, the correct answer is option A.

Quiescent centre is a

botany root - external morphology morphology of the root root system in plants root

  1. Weak zone

  2. Active zone

  3. Inactive zone

  4. Strong base

Show answer
Correct Option: C
Explanation:

Quiscent centre is a zone of mitotically inactive zone in the meristematic region of the root apical meristem. The cells of this region either do not divide or divide very slowly. They have thin cytoplasm, low concentration of the RNA and proteins, fewer endoplasmic reticulum and dictyosomes. This zone acts as reservoir of meristematic cells. The cells ar ecapable of gaining the active dision activity at the time of growth.

Hence, the correct answer is 'Inactive zone'.

Which of the following is absent in a root hair?

botany root - external morphology morphology of the root root system in plants root

  1. Cell wall

  2. Vacuole

  3. Nucleus

  4. Chloroplast

Show answer
Correct Option: D
Explanation:

Chloroplast are absent in root hairs because root hairs do not produce food. These are meant for absorption of water and minerals from soil. Chloroplast is the store house of chlorophyll which is the green pigment essential in photosynthesis.Moreover root and root hair are underground structures away from light, hence they do not contain chloroplasts, as chlorophyll pigments present within the chloroplasts are functional only in presence of light.

So, the correct answer is 'chloroplast'

Which of the following roots are found in a screwpine?

botany root - external morphology morphology of the root root system in plants root

  1. Nodulose

  2. Tuberous

  3. Stilt

  4. Fasciculated

Show answer
Correct Option: C
Explanation:

Screwpine or Pandanus also known as screw palm has stilt roots. Often called as Pandanus palms, these plants are not closely related to palm trees. The species vary in size from small shrubs less than 1 m. Species growing on exposed coastal headlands and along beaches have thick stilt roots- as anchors in the loose sand. Those prop roots emerge from the stem, usually close to but above the ground, which helps to keep the plants upright and secure them to the ground.
Thus, the correct answer is option C.

Transition of exarch bundles of root to endarch bundles of stem occurs in

botany root - external morphology morphology of the root root system in plants root

  1. Epicotyl

  2. Hypocotyl

  3. Apical bud

  4. Coleoptile

Show answer
Correct Option: B
Explanation:
Hypocotyl is the portion of seedling where transition of root structure into stem structure occurs. The seedling above the transition point has stem structure which is characterized by presence of collateral and endarch vascular bundles. And the region of hypocotyls below the transition point is structurally root, which bear radial and exarch vascular bundles. The transition point marks this conversion from exarch to endarch vascular bundles which makes option B correct. Epicotyl is the region of embryonic axis above the cotyledons which develops into leaves and is present above the hypocotyl; option A is incorrect. The protective covering that covers the epicotyls of monocot embryo is called as coleoptiles; they serve the protective function only; option D is incorrect. Apical bud is the meristematic tissue present in the tip of the stem and shoots which synthesize auxin and inhibits the lateral buds which are located in the base of the shoots; they are not involved in transition of root anatomy into stem anatomy; option C is incorrect.
Thus, the correct answer is option B.