0

Root system in plants - class-VII

Attempted 0/27 Correct 0 Score 0

In many plants the tap root becomes swollen and assume various forms. Match the following.

Plant Type of Root
A. Carrot 1. Conical
B. Mirabilis  2. Fusiform
C. Radish 3. Napiform
D. Turnip 4. Tuberous
  1. A - 1, B - 4, C - 2, D - 3

  2. A - 2, B - 3, C - 1, D - 4

  3. A - 4, B - 1, C - 3, D - 2

  4. A - 3, B - 2, C - 1, D - 4


Correct Option: A
Explanation:

1.The conical fleshy tap root resembles a cone, that is, the thickest towards base and gradually tapering towards the apex, e.g., Carrot (Daucus carota) 2.The fusiform fleshy root is like a spindle, that is, thickest roughly in the middle and narrow towards both its base and apex, e.g., Radish (Raphanus sativus). 3.The napiform fleshy root is very thick at the base and is almost spherical. It suddenly thins out towards the apex (top-like), e.g., Turnip (Brassica rapa ) 4.The tuberous roots are those thickened tap roots which do not assume any definite form, e.g., Mirabilis jalapa (Four O’ Clock). So, the correct option is A. (A - 1, B - 4, C - 2, D - 3)

Identify the correct pair of plants which produce pneumatophores : 

  1. Heritiera fomes and Dahlia bybrida

  2. Heritiera fomes and Ceriops roxburghiana

  3. Ceriops roxburghiana and Asparagus racemosus

  4. Tinospora cordifolia and Ipomoea batatus


Correct Option: B
Explanation:

Answer is option B i.e. "Heritiera fomes and Ceriops roxburghiana"
Pneumatophores (breathing roots) are modification of root that assist in respiration whenever there is water lodging near root. They are found in halophytes (plants which grow in saline conditions) and mangroves. In mangrove families like Heritiera fomes and Ceriops roxburghiana, pnematophores acts as an organ of gaseous exchange.

A partial (stem or root) parasitic plant is one which

  1. Draws food from host only at certain times

  2. Takes both water and nutrients from host plant

  3. Takes only water from host plant

  4. Uses the host just for support


Correct Option: B
Explanation:

Partial parasitic plants have chlorophyll which helps them to produce organic substances they require. They depend on the host for water and minerals, sometimes few chemical substances required for their growth. So, the correct option is B. ( Takes both water and nutrients from host plant )

Lateral roots in dicots are endogenous in origin and they are formed by:-

  1. A tissue which give rise to root cap

  2. A tissue which gives rise to cork cambium

  3. A tissue which also works as water checkdam

  4. A tissue which forms the primary vascular bundles


Correct Option: A

Most of the orchids are

  1. Epiphytes

  2. Parasites

  3. Saprophytes

  4. Hygophytes


Correct Option: A
Explanation:

Most orchids are epiphytes as they have epiphytic roots. Epiphytes are plants that grow anchored to other plants. They are non-parasitic. Epiphytic roots are adventitious roots found in the epiphytes. These roots are present in the air and absorb the moisture and nutrients from the air. Since epiphytic plants do not have roots in the soil, they are called as air plants. Epiphytic roots of orchids grow on the surface of other plants for getting shelter.

Thus, the correct answer is option A.

Identify the correct statement for monocotyledonous root

  1. pith is large and well developed

  2. No secondary growth

  3. polyarch condition

  4. All of the above


Correct Option: A

Soyabean root exports fixed nitrogen as _____ by _____  (respectively).

  1. Ureides; Phloem

  2. Ureides; Xylem

  3. Amides; Phloem

  4. Amino adds; Xylem by


Correct Option: A

Find out the incorrect statements.

  1. Secondary and tertiary roots of tap root are borne in acropetal succession

  2. Lateral roots arising from the primary root is exogenous in origin

  3. Primary root is the direct prolongation of radicle

  4. Root hairs are meant for water and mineral absorption


Correct Option: A

Groundnut, Bean and Alfalfa are members of the group

  1. Cruciferae

  2. Leguminosae

  3. Malvaceae

  4. Solanaceae


Correct Option: B
Explanation:

Groundnut, Bean and Alfalfa, all the three are legumes and thus the members of the family Leguminosae.

The roots that possess haustoria are called

  1. Photosynthetic root

  2. Reproductive root

  3. Respiratory root

  4. Parasitic root


Correct Option: D
Explanation:

A haustoria is a root-like structure or a structure that grows into or around another structure to absorb water or nutrients. The root of a parasitic plant that penetrates the host's tissue and draws nutrients from it.

The association of Nitrogen fixing bacteria (nodule bacteria) with leguminous roots is known as 

  1. Saprophytism

  2. Symbiosis

  3. Epiphytism

  4. Parasitism


Correct Option: B
Explanation:

Symbiosis is a type of association of dissimilar organisms of their mutual advantage, e.g., association of nitrogen-fixing bacteria (nodule bacteria) with leguminous roots. The bacteria, inhabiting nodules on roots manufacture compounds from the nitrogen of the air, which becomes available to the plant. From the plant, bacteria obtain carbohydrates and other food materials.

Fungi forming symbiotic relationship with plants

  1. Riccia

  2. Mycorrhiza

  3. Pinus

  4. None of these


Correct Option: B
Explanation:

Fungi are also known to form symbiotic relationship with plants (mycorrhiza). Many members of genus glomus forms mycorrhiza.

Baderoids are

  1. Enlarged non-motile cellular bacteria Rhizobium

    leguminosarum in root nodules of legumes

  2. A bacterial cell infected with viruses

  3. A motile bacterium

  4. Nitrosomonas bacteria in soil


Correct Option: A
Explanation:

Bacteroid : Symbiotic bacteria Rhizobium leguminosarum in leguminous plants e.g., gram, pea etc. in their roots nodules produce Leg haemoglobin  this whole Bacteria + Leg haemoglobin + Polyploide  cells of roots is called as bacteroid. 


Which of the following plants would have nitrogen fixing bacteria?

  1. Pea plant

  2. Tomato plant

  3. Cabbage plant

  4. Bottle gourd plant


Correct Option: A
Explanation:

Nitrogen fixing bacteria are found in the root nodules of leguminous plants. Pea plant being a legume such bacteria would be found in its roots.

Select the correct statements.
(a) From the region of elongation, some of the epidermal cells form root hairs.
(b) Pneumatophores are seen in Sonneratia.
(c) Adventitious roots are seen in Banyan tree.
(d) Maize and Sugarcane have prop roots.

  1. a and d

  2. a, c and d

  3. c and d

  4. b and c

  5. a, b and d


Correct Option: D

Swollen root of Radish is made of two parts.

  1. Stem and epicotyl

  2. Primary root and hypocotyl

  3. Primary root and epicotyl

  4. Secondary root and primary root


Correct Option: D

Peculiarity of Dalbergia tap root system is?

  1. Surface feeder

  2. Presence of nodules

  3. Formation of buds

  4. Lenticels for aeration


Correct Option: A
Explanation:

Dalbergia is the fast-growing, hardy and surface feeder tap root. They are having a long taproot and numerous surface roots as well. In surface feeders, the taproot does not grow or develop to a great extent.

The cymose or surface feeder tap root systems of some annual plants are consisting of thin fibrous roots. Therefore, also called a fibrous tap root system.

The correct option is A.

In Tinopsora, the adventitious roots are.

  1. Hanging

  2. Green

  3. Both A and B

  4. Clinging in nature


Correct Option: C
Explanation:

Modified adventitious roots, which become green colour and perform photosynthesis. These are called as assimilatory roots, for example, Taeniophyllum, Trapa, Tinospora cordifolia. Tinospora is having climbing photosynthetic roots and is aerial. These are like the green hanging threads developing from the nodes during the rainy seasons.

The correct answers are A and B both. 

In fern Salvinia, the adventitious roots are.

  1. Storage in function

  2. Spongy due to aerenchyma

  3. Green and photosynthetic

  4. Modification of leaf


Correct Option: D

Assertion : Allelopathy is a form of ammensalism that occurs in plants

Reason : Association of rooting plants with fungal hyphae, is an important example of ammensalism.


  1. If both the assertion and the reason are true and the reason is a correct explanation of the assertion

  2. If both the assertion and reason are true but the reason is not a correct explanation of the assertion

  3. If the assertion is true but the reason is false

  4. If both the assertion and reason are false

  5. If the assertion is false but reason is true


Correct Option: C
Explanation:

Allelopathy is a phenomenon associated with plants, in which one plant produce some chemical substances, which inhibits the growth of other plant species. While, in ammensalism, one species suffer and other remain unaffected.

Nodulation of legumes is reduced in deficiency of.

  1. Sulphur and potassium

  2. Sulphur and boron

  3. Manganese and copper

  4. Zinc


Correct Option: A

Read the following four statements:
(A) A simple experiment called girdling was used to identify the tissue through which food is translocated.
(B) Plant factors that effect transpiration include temperature, light, wind velocity and humidity.
(C) Most of the water flow in root occur via apoplast.
(D) In young root, water directly enters into the xylem vessels.
How many of the above statements are right?

  1. Four

  2. Three

  3. Two

  4. One


Correct Option: A

Mycorrhizal association controls root affecting pathogens in plants because.

  1. Mychorrhizal fungi colonize the roots and acts as a barrier during infection

  2. Mychorrhizal fungi helps in phosphorus uptake

  3. Mychorrhizal fungi help during stress and shock

  4. Mychorrhizal fungi produce toxins against pathogens


Correct Option: A

Select the incorrect match with respect to the plant and the relative plant part modified for food storage.

  1. Lathyrus odoratus (sweet potato) - Root

  2. Solanum tuberosum (potato) - Stem

  3. Allium cepa (onion) - Leaves

  4. Dahlia (Dahlia) - Leaves


Correct Option: D
Explanation:

The incorrect match is: 

Dahlia(Dahlia) - Leaves
So, the correct answer is (d).

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

  1. Hydrophytes

  2. Periphytes

  3. Epiphytes

  4. Epinastic plants


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

  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


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

  1. Vanda

  2. Rosa

  3. Viscum

  4. Sanctalum


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'.

- Hide questions