Biology

Photosynthesis in Plants

1,492 Questions

Photosynthesis is the biological process by which plants convert light energy into chemical energy. This page contains practice questions covering essential topics like chlorophyll, light reactions, and the pathways specific to plants. This material is crucial for medical entrance exams and academic assessments.

Chlorophyll and pigmentsLight reactionsCalvin cycleCAM plantsElectron transportPhotosynthesis factors

Photosynthesis in Plants Questions

Multiple choice zoology microbes in human welfare biofertilizers microbes as biocontrol agents and biofertilizers manuring

Nostoc is known to do

  1. Photosynthesis
  2. Photosynthesis and $N _2$ fixation simultaneously
  3. $N _2$ fixation only
  4. Either photosynthesis or $N _2$ fixation at a time
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Nostoc is a genus of blue green algae. It is photosynthetic cyanobacteria. It contains chlorophyll pigment and carries out photosynthesis. It also has ability to fix atmospheric nitrogen and make it available to the plants. It is a non-symbiotic nitrogen fixer.

Thus, the correct answer is 'Photosynthesis and N$ _2$ fixation simultaneously.'

Multiple choice zoology microbes in human welfare biofertilizers microbes as biocontrol agents and biofertilizers manuring

In blue green algae, photosynthesis occurs at

  1. Chromatophore

  2. Chloroplast

  3. Photosynthetic lamellae or thylakoids

  4. Chromoplast
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Since, BGA is a prokaryotic organism, they lack true nucleus and membrane bound organelles which means that chloroplast (double membrane bound chlorophyll containing plastids) is absent in them. Thus, option B is incorrect. Chromatophores are light reflecting, pigment containing cells. The peripheral region of BGA protoplast contains thylakoids and is termed as chromoplast. Thylakoids contain photosynthetic pigments (chrolophyll a, xanthophylls, phycobilin) in their membranes and serve as site for photosynthesis. Thus, option C is correct and D is incorrect.

Multiple choice zoology microbes in human welfare biofertilizers microbes as biocontrol agents and biofertilizers manuring

Blue colour of blue-green algae is due to

  1. Phycocyanin and allophycocynanin

  2. Phycoerythrin

  3. Anthocyanin

  4. Anthoxanthin
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Blue-green algae are also called as cyanobacteria. The blue colour of blue-green algae is due to presence of pigments phycocyanin and allophycocyanin. The green colour is due to presence of chlorophyll pigment. Phycoerythrin pigment results in the red colour. Anthocyanins pigment gives red, purple and blue colours in many fruits and vegetables. Anthoxanthin pigment gives white or colorless to a creamy to yellow color to petals of flowers.

Thus, the correct answer is 'Phycocyanin and allophycocynanin.'

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Pigment containing membranous extensions in some cyanobacteria are

  1. Chromatophores

  2. Heterocysts

  3. Basal bodies

  4. Penumatophores
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In cyanobacteria, the pigment-containing membranous extensions that facilitate photosynthesis are called chromatophores (or thylakoids). Heterocysts are specialized cells for nitrogen fixation, not pigment storage.

Multiple choice zoology microbes in human welfare biofertilizers microbes as biocontrol agents and biofertilizers manuring

What is the photosynthetic product in blue-green algae?

  1. Normal starch

  2. Glycogen

  3. Cyanophycean starch resembling glycogen

  4. None of these
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation
Blue-green algae, also called cyanobacteria, any of a large, heterogeneous group of prokaryotic, principally photosynthetic organisms. Cyanobacteria resemble the eukaryotic algae in many ways, including morphological characteristics and ecological niches, and were at one time treated as algae, hence the common name of blue-green algae. The process of photosynthesis goes on in cyanobacteria in the same manner as in plants. The storage food products in cyanobacteria are somewhat different from those of green plants. The storage product is usually a starch like substance similar to glycogen and is different from the starch produced in plants. This is known as Cyanophycean starch.

So, the correct answer is 'Cyanophycean starch resembling glycogen'.
Multiple choice bio-chemistry carbohydrate metabolism energy output living organisms and energy production respiration in cell

Both photosynthesis and cellular respiration are metabolic processes that occur in eukaryotic cells. Each process involves several steps and chemical reactions.
All of the following occur during the processes of photosynthesis and cellular respiration except

  1. The production of large amounts of ATP.

  2. Oxidation-reduction reactions.

  3. The use of multiple enzymes to catalyze reactions.

  4. An electron transport chain.
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Production of large amount of ATP takes place exclusively during respiration. However a small number of ATP is produced during the light reaction of photosynthesis, which is utilized for fixing or reducing CO$ _2$

So, the correct answer is 'The production of large amounts of ATP'

Multiple choice bio-chemistry carbohydrate metabolism energy output living organisms and energy production respiration in cell

In photosynthesis energy from light reaction to dark reaction is transferred in the form of 

  1. ADP

  2. ATP

  3. RUDP

  4. Chlorophyll
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

ATP is the energy currency. Assimilatory power is the power of plants in the form of ATP and NADPH to obtain food in the form of carbohydrates from the reduction of $CO _2$ during photosynthesis.

Multiple choice biology plant growth and development other plant hormones cytokinins, ethylene and abscisic acid plant hormones

Choose the correct answer from the alternatives given.
The phytochrome system helps to entrain the biological dock by indicating to a plant that light is present when:

  1. Pr is rapidly converted to Pfr

  2. Pfr is slowly converted to Pr

  3. Pr and Pfr are equal in concentration

  4. red light is absorbed by Pfr
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The biological clock is the seasonal or physiological activities of the plant which changes according to time, season etc. When the light is present at the time of the night, the phytochrome system sends the signal to the biological clock which results in the activation of phytochromes thus converting Pr (Inactive form) to Off (active form). This results in the flowering of plants.

So, the correct option is 'Pr is rapidly converted to Pfr'.

Multiple choice botany adaptations to different ecosystems lichen lichens lichens ( the nature's pioneers )

Which of the following physiological process happens in lichens when the phycobiont is a cyanobacteria?

  1. Nitrogen fixation

  2. Carbon fixation

  3. Carbon assimilation

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The fungal part of the lichens is known as mycobiont. Cyanobacteria have a special structure known as heterocyst which is specialised to perform nitrogen fixation. It has specific enzymes like nitrogenase which actively fixes the atmospheric nitrogen to a usable form. They are autotrophic so they also fix carbon during the dark reaction of photosynthesis into organic compounds. This conversion process of inorganic carbon (carbon dioxide) to organic compounds is also known as carbon assimilation.

So, the correct answer is 'Nitrogen fixation, Carbon fixation and Carbon assimilation'.

Multiple choice botany cell structure and organization membrane bound organelles cell: size and differentiation microscopy

Anthocyanin occurs in

  1. Chloroplasts

  2. Vacuole

  3. Leucoplasts

  4. Chromoplasts
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • The plant vacuoles consist of various water-soluble pigments such as carotenoids, anthocyanins and xanthophylls etc.
  • Anthocyanins are also water-soluble pigments which are red, purple, or blue in colour depending on the pH which gives colour to the flower and fruits (blueberry, raspberry etc).
  • So, the correct answer is 'Vacuoles'.