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 botany living world of plants - plant physiology historical events in photosynthesis history of photosynthesis introduction to photosynthesis

Photosynthesis is the conversion of light energy within a plant was first stated by

  1. Willstatter and Stoll

  2. Mayor and Anderson

  3. Benson and Calvin

  4. Robert Mayer
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Julius Robert von Mayer was a German physician and physicist. He was the first to state the law of the conservation of energy i.e., energy is neither created nor destroyed. He stated that the sun is the ultimate source of energy for both plants and animals and that when absorbed plants convert this light energy through the process of photosynthesis.

Multiple choice botany living world of plants - plant physiology historical events in photosynthesis history of photosynthesis introduction to photosynthesis

Who stated that in photosynthesis light energy is converted into chemical energy?

  1. R. Mayer

  2. Willstatter and Stoll

  3. Arnon

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

Photosynthesis is a process by which green plants manufacture their food with the help of carbon dioxide and water in the presence of sunlight. When light energy is absorbed by photosynthetic pigment chlorophyll, then it gets exited and photosynthetic reaction center loses an electron. In this way, light energy is converted to chemical energy. Conversion of light energy into chemical energy is the primary event in photosynthesis. R. Mayer stated that in photosynthesis light energy is converted into chemical energy. He also proposed that the sun is the ultimate source of energy utilized by living organisms.

Multiple choice botany living world of plants - plant physiology historical events in photosynthesis history of photosynthesis introduction to photosynthesis

Most of the experimental work in photosynthesis has been done on 

  1. Chlamydomonas

  2. Chlorella

  3. Hydrilla

  4. Spinach leaf
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation
  • Most of the experimental work in photosynthesis has been done on Chlorella. Through photosynthesis it multiplies rapidly, requiring only carbon dioxide, water, sunlight and a small number of minerals to reproduce. 
  • It is easy to culture and it is easy to understand the photosynthetic process in chlorella cells.
  •  Based on the above advantages most of the photosynthetic work was conducted in chlorella compared to hydrilla, spinach leaves, and Chlamydomonas. 
Multiple choice biology the leaf mechanism of absorption mineral absorption significance of transpiration

Photosynthesis is essential for survival of

  1. Animals

  2. Plants

  3. Most of the organisms

  4. All of the above
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
Photosynthesis is plants taking in water, carbon dioxide, and light to make sugar and oxygen. This is important because all living things need oxygen to survive. All producers make oxygen and sugar for the secondary consumers and then the carnivores eat animals that eat the plants. If there is not enough producers to make the sugar and oxygen that all living things need then all living things will die out. Without producers CO2 couldn't be taken in by the plants to be turned back into oxygen that all animals need for survival. Also, without producers, herbivores wouldn't have anything to eat and they would all die leaving carnivores without food to eat and all life forms wouldn't be on Earth. Photosynthesis happens in the Chloroplast of the plant's organelle, if the Chloroplast wasn't in the plant Photosynthesis couldn't happen. If there was no sunlight for the plant to absorb then Photosynthesis couldn't happen. If living things didn't breathe out CO2 then the plants would die and living things would have no way of getting oxygen. These are the reasons why Photosynthesis is important to plants and all loving things on the planet.

So, the correct option is 'Option D'.
Multiple choice biology the leaf mechanism of absorption mineral absorption significance of transpiration

Photosynthesis in CAM-plants in minimal because of the limited amount of _________________.

  1. $CO _{2}$ fixed at night
  2. $O _{2}$ fixed at night
  3. $O _{2}$ fixed at day light
  4. $CO _{2}$ fixed at day light
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

CAM plants fix CO2 at night to minimize water loss. The total amount of photosynthesis is limited by the amount of CO2 they can fix during the night, which is stored as organic acids.

Multiple choice biology the leaf mechanism of absorption mineral absorption significance of transpiration

With reference to factors affecting the rate of photosynthesis, which of the following statements is not correct?

  1. Increasing atmospheric $CO _{2}$ concentration up to $0.05$% can enhance $CO _{2}$ fixation rate
  2. $C _{3}$ plants respond to higher temperatures with enhanced photosynthesis while $C _{4}$ plants have much lower temperature optimum
  3. Tomato is a greenhouse crop which can be grown in $CO _{2}$ - enriched atmosphere for higher yield

  4. None of above
Reveal answer Fill a bubble to check yourself
A Correct answer
Multiple choice biology the leaf mechanism of absorption mineral absorption significance of transpiration

A small mesophytic twig with green leaves is dipped into water in a big beaker under sunlight. It demonstrates

  1. Photosynthesis

  2. Respiration

  3. Transpiration

  4. None of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

There will be loss of water through the leaves if the beaker is kept covered. Otherwise direct evaporation of water from free surface will also happen. The purpose of this experiment is to demonstrate transpiration, which is loss of water through leaves of plants in vapour form.

Multiple choice biology the leaf mechanism of absorption mineral absorption significance of transpiration

Which of the following is the significance of photosynthesis?

  1. Balance of carbon dioxide and oxygen

  2. Balance of nitrogen in the environment

  3. Provides food

  4. Both A and C
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In the atmosphere, plants prepare food due to photosynthesis and release oxygen and animals release carbon dioxide by respiration. Animals inhale oxygen released by plants and plants use carbon dioxide for the process of photosynthesis. Hence balance of carbon dioxide and oxygen is maintained by photosynthesis. Plants use energy from sunlight to turn water and carbon dioxide into an energy-rich sugar called glucose.which is stored as starch inside the plant body. Plants provide food in the form of carbohydrates(glucose and starch).

So, the correct answer is 'Both A and C'.

Multiple choice evs modern agriculture agricultural practices in india different types of farming and agriculture various agricultural practices

Green house crops such as tomatoes and bell pepper produce higher yields. This is due to.

  1. Tomatoes and bell pepper are not $C _3$ plants

  2. Due to diffused light in green house
  3. $CO _2$ is limiting factor to photosynthesis
  4. $CO _2$ enriched atmosphere leads to higher yield
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation
  • Growing crops in greenhouse produce higher yields due to a lot of reasons like - temperature control, carbon dioxide factor, reduced pest and disease exposure and humidity. 
  • The concentrated carbon dioxide results in larger leaves, stronger plant stems and possible early flowering and fruiting.
  • So the correct option is 'CO2 enriched atmosphere leads to higher yield'.
Multiple choice botany ecological adaptations, succession and ecological services ecosystem services ecosystems ecosystem

The process of photosynthesis and respiration cause the cycling of ........... through the environment.

  1. Carbon

  2. Water

  3. Nitrogen

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

The plants can fix carbon dioxide from the atmosphere which is taken in through stomata. The carbon dioxide is converted in the presence of light and chlorophyll pigments to synthesize carbon containing organic compounds such as sugar, fats and proteins. This creates the plant biomass which when eaten by other organisms recycles the carbon from on level to other. Finally the carbon enters the geosphere and then the atmosphere. The oxygen which is formed during photosynthesis is liberated in the atmosphere and used for cellular respiration. The oxygen is used to break down the molecules and release the carbon dioxide. The carbon gets recycled in the environment from plants to animals and then again enters the environment. 

Thus, the correct answer is option A. 

Multiple choice zoology environmental science structure of earthworm earthworm - morphology, integumentary system , respiration and nervous system adaptations

Choose the correct answer from the alternatives given.
The yellowing of leaves, called chlorosis, is usually caused by the deficiency of:

  1. sodium

  2. phosphorus

  3. magnesium

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

A magnesium-deficient crop will tend to have a pale overall colour. The earliest specific symptom of magnesium deficiency is interveinal chlorosis of older leaves. Chlorosis generally progresses to yellowing and necrosis of the oldest leaves. Therefore, without sufficient amounts of magnesium, plants begin to degrade the chlorophyll in the old leaves. This causes the main symptom of magnesium deficiency, interveinal chlorosis, or yellowing between leaf veins, which stay green, giving the leaves a marbled appearance.

So, the correct option is, 'Magnesium'.