MCQs: Nutrition in Plants | NCERT Textbooks (Class 6 to Class 12) - CTET & State TET PDF Download

Q1: Which of the following is true about saprophytes?
(a) They trap insects to meet their nitrogen requirement.
(b) They live on decaying organic matter.
(c) They share their food and shelter.
(d) Saprophytes contain chlorophyll.
Ans: (b)
A saprophyte or saprotroph is an organism that gets its nutrition and energy from dead and decaying organic matter. These may be decaying parts of plants or animals. This means that saprophytes are heterotrophs. They are consumers in the food chain. This is a phenomenon observed in Fungi.
So, the correct answer is '(b)'.

Q2: Which of the following statements is incorrect about leghaemoglobin?
(a) It acts as O₂ scavenger
(b) It imparts pink or red colour to the nodules
(c) It combines with O₂ and protects nitrogenase
(d) It is a Mo-Fe protein.
Ans: (d)

Q3: Stomata are present on the underside of the __________.
(a) Flower
(b) Fruit
(c) Seed
(d) Leaf
Ans: (d)
Stomata consist of openings (stomatal pores) surrounded by the guard cells. These are present mostly on the underside of the leaves and perform the functions of exchange of gases and transpiration.
Hence, the correct answer is 'Leaf'.

Q4: The correct statement(s) among I to III with respect to potassium ions that are abundant within the cell fluids is/are:
(i) Along with sodium ions, they are responsible for the transmission of nerve signals.
(ii) Potassium plays an important role in maintaining resting membrane potential across the cell membrane.
(iii) Potassium is an essential mineral needed to regulate water balance, blood pressure and levels of acidity.
(a) I and III only
(b) I and II only
(c) I, II and III
(d) III only
Ans: (c)

Q5: The nodules present in the leguminous plants appear pink in colour due to the presence of
(a) RBC.s
(b) leghaemoglobin
(c) nitrogenase enzyme
(d) bacterial secretion
Ans: (b)

Q6 _______ conditions are created by leghaemoglobin in the root nodule of a legume.
(a) Aerobic
(b) Anaerobic
(c) Acidic
(d) Alkaline
Ans: (b)

Q7: Function of leghaemoglobin (a red pigment) in root nodules of leguminous plants is:
(a) To regulate O₂ supply in cells.
(b) To regulate CO₂ supply in cells.
(c) To regulate production of phenolic compounds.
(d) To regulate the Mo supply in cells.
Ans: (a)
Leghemoglobin supports the centralization of free oxygen in the cytoplasm of contaminated plant cells to guarantee the best possible capacity of root knobs.
Its capacity is to help give oxygen to the breathing harmonious bacterial cells in root nodules of leguminous plants in a way practically equivalent to hemoglobin transporting oxygen to breathing tissues in creatures.
Thus, the correct answer is option A- 'to regulate O₂ supply in cells.'

Q8: Organisms which prepare food for themselves using simple naturally available raw materials are referred to as
(a) Heterotrophs
(b) Autotrophs
(c) Parasites
(d) Saprophytes
Ans: (b)
An organism that prepares food for itself using Carbon dioxide, water in the existence of 'sunlight' and 'chlorophyll' is referred to as 'autotrophs'.
Heterotrophs depend on other autotrophs for nutrition.
Parasites live inside other organisms and depend on that organism for nutrition.
Saprophytes feed on dead decaying organisms.
Thus, the correct answer is option (b).

Q9: The term that is used for the mode of nutrition in yeast, mushroom and bread mould is ________.
(a) Autotrophic
(b) Insectivorous
(c) Saprophytic
(d) Parasitic
Ans: (c)
Yeast, mushroom, and bread mould (Rhizopus) are saprophytic because they obtain food from decaying and dead matter.
So, the correct answer is option (C).

Q10: Select the correct statement(s).
(a) Heterotrophs do not synthesise their own food.
(b) Heterotrophs utilise solar energy for photosynthesis
(c) Heterotrophs synthesise their own food
(d) Heterotrophs are capable of converting carbon dioxide and water into carbohydrates.
Ans: (a)
Heterotrophs are the organisms that cannot synthesize their own food and derive it from other sources directly or indirectly and autotrophs are the organisms like plants that synthesize their own food by help of CO₂ and water.
So the correct answer is " Heterotrophs do not synthesise their own food.".

Q11: Which of the following statements is/are correct?
(i) All green plants can prepare their own food.
(ii) Most animals are autotrophs.
(iii) Carbon dioxide is not required for photosynthesis.
(iv) Oxygen is liberated during photosynthesis.
Choose the correct answer from the options below
(a) (i) and (iv)
(b) (ii) only
(c) (ii) and (iii)
(d) (i) and (ii)
Ans: (a)
All the green plants are - producers" so they can set up their own food.
Animals don't make their own food. They are heterotrophs.
Carbon dioxide and water required for the process of photosynthesis in plants.
Oxygen liberates in the process of photosynthesis.
Statement (I) and (iv) are the correct statements.
The correct answer is (a).

Q12: Identify the part of the cell by the hints given:
This part of the cell is present in ALL cells. It is the gel-like substance that provides cell shape.
(a) Cytoplasm
(b) Chromosomes
(c) Nucleus
(d) Cell membrane
Ans: (a)
The gel like substance which give shape to cell is called Cytoplasm. Option (a) is correct.

Q13: Why are most cells so small?
(a) We can see them with a microscope.
(b) They can fit in our bodies.
(c) They can reproduce quickly.
(d) They can take in food and get rid of waste.
Ans: (d)
Cells are so little, so they can maximize their ratio of surface area to volume. Smaller cells have a higher ratio which allows more molecules and ions to move across the cell membrane per unit of cytoplasmic volume. Cells are so small because they need to be able to get the nutrients in and the waste out quickly.

Q14: What cell part is NOT present in all the cells?
(a) Cell Wall
(b) Genetic material
(c) Cell membrane
(d) Cytoplasm
Ans: (a)
Cell wall is only found in plant cells and not in any other cells. Option (a) is correct.

Q15: The insectivorous plants are____________.
(a) heterotrophs
(b) partial heterotrophs
(c) omnivores
(d) partial omnivores
Ans: (b)
The insectivores depend on the insects for external nutrients which can't be prepared by them. Thus, they are partial heterotrophs. Option (b) is correct.

Q16: What tool do you use to view the cells?
(a) Microscope
(b) Microruler
(c) Microlasers
(d) All of the above
Ans: (a)
Cells are observed under Microscope for detailed resolution.
Option A is correct.

Q17: The association of Rhizobium  with Leguminous plants is called__________.
(a) Symbiotic relationship
(b) Parasitic relationship
(c) Predatory relationship
(d) Both (a) and (b)
Ans: (a)
Rhizobium cannot make its own food. So it often lives in the roots of gram, peas, moong, beans and other legumes and provides them with nitrogen.
In return, the plants provide food and shelter to the bacteria. They, thus, have a symbiotic relationship. Option (a) is correct.

Q18: Which life process is classified as autotrophic in some organisms and heterotrophic in others?
(a) Hormonal regulation
(b) Nutrition
(c) Anaerobic respiration
(d) Transport
Ans: (b)
Nutrition is classified as autotrophic and heterotrophic. Autotrophic organisms can synthesise their own food (e.g., green plants, blue-green algae and some bacteria. While some organisms exhibit a heterotrophic mode of nutrition as they are unable to synthesise their own food. They may be parasitic, saprozoic (animal) or saprophytic (plant) and symbiotic (many bacteria, fungi, algae).

Q19: Leguminous plants are important in agriculture because
(a) They are disease resistant
(b) They have high amounts of proteins
(c) They require less nitrogen for growth
(d) Nitrogen fixing bacteria are symbiotically associated in them
Ans: (d)
Leguminous plants are important in agriculture because they contribute to nitrogen fixation. They contain symbiotic nitrogen-fixing bacteria within the nodules that produce nitrogen compounds that help the plant to grow. When the plant dies, the fixed nitrogen is released, making it available to other plants and this helps to fertilize the soil.
So the correct answer is 'Nitrogen-fixing bacteria are symbiotically associated in them'.

Q20: What are outside raw materials used by an organism?
(a) Food by heterotrophic organisms
(b) Carbon dioxide, minerals and water by autotrophic organisms
(c) Oxygen by all aerobic organisms
(d) All of the above
Ans: (c)
Autotrophic organisms can synthesize their own food whereas heterotrophic organisms depend on autotrophs for their food supply. Green plants are the most common autotrophs. They synthesize sugars during the process of photosynthesis. These organisms absorb water and minerals from the soil and use the energy of the sun to synthesize sugars (carbohydrates).  Heterotrophs like animals consume plants either directly (herbivores) or indirectly (carnivores). All living organisms carry on the process of respiration in which the biomolecules are broken down into simpler molecules and energy is released. The process of respiration can occur in the presence (aerobic) or absence of oxygen (anaerobic). Thus, the correct answer is option (d).