NEET Biology Photosynthesis in Higher Plants MCQs Set 23

Answer: (b) 400 nm - 700 nm

Explanation:
1. PAR (Photosynthetically active radiations) ranges between the wavelength 400- 700nm.
2. Hence option (b) is correct: 400 nm - 700 nm

Teacher's Note:
1. Photosynthesis: separate the light reactions (grana) from the Calvin cycle (stroma) and remember the ATP and NADPH needs.
2. C3 and C4 comparisons are a favourite, so tabulate them.

Answer: (d) Both Assertion and Reason are false.

Explanation:
1. Mitochondria helps in cellular respiration by transferring energy from organic compounds to ATP. Chloroplast helps in photosynthesis.
2. Dark reaction takes part in the stroma of the chloroplast.
3. Hence option (d) is correct: Both Assertion and Reason are false.

Teacher's Note:
1. C3 and C4 comparisons are a favourite, so tabulate them.
2. Photosynthesis: separate the light reactions (grana) from the Calvin cycle (stroma) and remember the ATP and NADPH needs.

Answer: (b) Both Assertion and Reason are true but the Reason is not a correct explanation of the Assertion.

Explanation:
1. In bacteria, photosynthesis utilizes light wavelength more than 700 nm and their reaction centre is B-890.
2. Hence option (b) is correct: Both Assertion and Reason are true but the Reason is not a correct explanation of the Assertion.

Teacher's Note:
1. Photosynthesis: separate the light reactions (grana) from the Calvin cycle (stroma) and remember the ATP and NADPH needs.
2. C3 and C4 comparisons are a favourite, so tabulate them.

Answer: (c) Assertion is true but the Reason is false.

Explanation:
1. Anthocyanin pigments only give colouration since the epidermal cells mainly have potential colouring pigments.
2. It is responsible of blue, red, pink and purple colours, observed in different parts of plants such as petals, stamens and fruits etc.
3. Hence option (c) is correct: Assertion is true but the Reason is false.

Teacher's Note:
1. Anthocyanin are also important for attracting insects for pollination and seed dispersal.
2. Hence, Anthocyanin pigments are not accessory photosynthetic pigments.

Answer: (b) Both Assertion and Reason are true but the Reason is not a correct explanation of the Assertion.

Explanation:
1. Photosynthetic bacteria have a substance called bacteriochlorophyll.
2. The bacterio- chlorophyll pigment absorbs light in the extreme UV and infra-red parts of the spectrum which is outside the range used by normal chlorophyll, seen in plants.
3. Hence option (b) is correct: Both Assertion and Reason are true but the Reason is not a correct explanation of the Assertion.

Teacher's Note:
1. Photosynthesis: separate the light reactions (grana) from the Calvin cycle (stroma) and remember the ATP and NADPH needs.
2. C3 and C4 comparisons are a favourite, so tabulate them.

Answer: (a) Both Assertion and Reason are true and the Reason is a correct explanation of the Assertion.

Explanation:
1. C4 pathway/Hatch and Slack pathway ensures the Calvin cycle to be operated only in bundle sheath cell.
2. It is an adaptation to photorespiratory loss.
3. Hence option (a) is correct: Both Assertion and Reason are true and the Reason is a correct explanation of the Assertion.

Teacher's Note:
1. Therefore, C4 plants are adapted to photorespiratory loss.
2. C3 and C4 comparisons are a favourite, so tabulate them.

Answer: (c) Assertion is true but the Reason is false.

Explanation:
1. Compensation point is that value or point in the light intensity and atmospheric CO₂ concentration when the rate of photosynthesis is just equivalent to the rate of respiration in the photosynthetic organ.
2. So that there is not net gaseous exchange.
3. Hence option (c) is correct: Assertion is true but the Reason is false.

Teacher's Note:
1. Photosynthesis: separate the light reactions (grana) from the Calvin cycle (stroma) and remember the ATP and NADPH needs.
2. C3 and C4 comparisons are a favourite, so tabulate them.

Answer: (c) Assertion is true but the Reason is false.

Explanation:
1. Photorespiration is the uptake of O₂ and release of CO₂ in light and results from the biosynthesis of glycolate in chloroplasts and subsequent metabolism of glycolate acid in the same leaf cell.
2. During photorespiration loss of carbon takes place in the form of CO₂.
3. Hence option (c) is correct: Assertion is true but the Reason is false.

Teacher's Note:
1. C3 and C4 comparisons are a favourite, so tabulate them.
2. Photosynthesis: separate the light reactions (grana) from the Calvin cycle (stroma) and remember the ATP and NADPH needs.

Answer: (d) Both Assertion and Reason are false.

Explanation:
1. C4 plants are more efficient in picking up CO₂ even when it is found in low concentration because of its high affinity for PEP. They show kranz anatomy i.e. vascular bundle is surrounded by bundle sheath and mesopyll cells.
2. Hence option (d) is correct: Both Assertion and Reason are false.

Teacher's Note:
1. Photosynthesis: separate the light reactions (grana) from the Calvin cycle (stroma) and remember the ATP and NADPH needs.
2. C3 and C4 comparisons are a favourite, so tabulate them.

Answer: (d) Both Assertion and Reason are false.

Explanation:
1. Dark reaction is also known as light- independent phase.
2. Unlike, light reaction, it does not require light as an essential factor.
3. Hence option (d) is correct: Both Assertion and Reason are false.

Teacher's Note:
1. Thus, can take place both in the presence or absence of light.
2. The term dark reaction does not mean that it takes place only in dark period or at night.

Answer: (b) Both Assertion and Reason are true but the Reason is not a correct explanation of the Assertion.

Explanation:
1. Amaranthus sp and sugarcane are known as Hatch and Slack plants.
2. In Hatch and Slack pathway, one glucose molecule is formed by fixation of 6CO2 in the plants.
3. Hence option (b) is correct: Both Assertion and Reason are true but the Reason is not a correct explanation of the Assertion.

Teacher's Note:
1. C3 and C4 comparisons are a favourite, so tabulate them.
2. Photosynthesis: separate the light reactions (grana) from the Calvin cycle (stroma) and remember the ATP and NADPH needs.

Answer: (a) Both Assertion and Reason are true and the Reason is a correct explanation of the Assertion.

Explanation:
1. DCMU (Dichlorophenyl dimethyl urea) is a herbicide that can prevent non cyclic photophosphorylation and oxygen production.
2. It inhibits photolysis of water.
3. Hence option (a) is correct: Both Assertion and Reason are true and the Reason is a correct explanation of the Assertion.

Teacher's Note:
1. Photosynthesis: separate the light reactions (grana) from the Calvin cycle (stroma) and remember the ATP and NADPH needs.
2. C3 and C4 comparisons are a favourite, so tabulate them.

Answer: (c) Assertion is true but the Reason is false.

Explanation:
1. Each molecule of ribulose-1, 5-biphosphate fixes one molecule of carbon dioxide with the addition of water, thereby resulting in the formation of two molecules of 3-phosphoglyceric acid (3-PGA).
2. The fixation and reduction of one molecule of CO₂ requires three molecules of ATP and two of NADPH, coming from the photochemical reactions.
3. Hence option (c) is correct: Assertion is true but the Reason is false.

Teacher's Note:
1. C3 and C4 comparisons are a favourite, so tabulate them.
2. Photosynthesis: separate the light reactions (grana) from the Calvin cycle (stroma) and remember the ATP and NADPH needs.

Answer: (b) Both Assertion and Reason are true but the Reason is not a correct explanation of the Assertion.

Explanation:
1. Light reaction or Hill reaction results in the formation of ATP and NADPH2, 6CO2, 6H2O, ATP and NADPH2 are utilised to produce one molecule of glucose.
2. Respiration in Plants 14.
3. Hence option (b) is correct: Both Assertion and Reason are true but the Reason is not a correct explanation of the Assertion.

Teacher's Note:
1. Photosynthesis: separate the light reactions (grana) from the Calvin cycle (stroma) and remember the ATP and NADPH needs.
2. C3 and C4 comparisons are a favourite, so tabulate them.