Photosynthesis

What is the process that plants use to make their own food?

• Aerobic cellular respiration

• Photosynthesis

• Fermentation

• Glycolysis

Answer explanation

The process that plants use to make their own food is called 'Photosynthesis'. During photosynthesis, plants convert sunlight, carbon dioxide, and water into food and oxygen. The other options: Aerobic cellular respiration, Fermentation, and Glycolysis, are processes that organisms use to break down sugar and produce energy, not the processes that plants use to make food.

What gas is produced during photosynthesis?

• Oxygen

• Carbon dioxide

• Nitrogen

• Hydrogen

Answer explanation

The process of photosynthesis involves the absorption of light by chlorophyll and the use of this energy to convert carbon dioxide and water into glucose and oxygen. Thus, the gas produced during photosynthesis is oxygen.

Which pigment do plants commonly use to capture light?

• Chlorophyll

• Melanin

• Carotene

• Anthocyanin

Answer explanation

The question is asking about the pigment that plants commonly use for light absorption. Chlorophyll is the correct answer. It is the most common pigment used by plants in photosynthesis to capture light energy, converting it into chemical energy. The other options, Melanin, Carotene, and Anthocyanin, are not predominantly involved in this function.

Where do the light dependent reactions of photosynthesis occur?

• Mitochondria

• Nucleus

• Thylakoids

• Stroma

Answer explanation

The light dependent reactions of photosynthesis occur in the thylakoids. Thylakoids are part of the chloroplasts in plants and are the site where light dependent reactions take place. These reactions are the first stage of photosynthesis and convert light energy into chemical energy. Mitochondria, nucleus and stroma are not involved in these reactions.

What is the alternative name for the light independent reactions of photosynthesis?

• Calvin Cycle

• Krebs Cycle

• Glycolysis

• Electron Transport Chain

Answer explanation

The question asks for the alternative name for the light independent reactions of photosynthesis. The correct answer is 'Calvin Cycle'. This is because the Calvin Cycle is the series of biochemical, enzyme-mediated reactions during photosynthesis occurring in the chloroplast; these reactions are not directly dependent on light, thus 'light-independent'. The other options, Krebs Cycle, Glycolysis, and Electron Transport Chain, are processes related to cellular respiration, not photosynthesis.

What is the main product of the light independent reactions of photosynthesis?

• Glucose

• Oxygen

• ATP

• NADPH

Answer explanation

The light-independent reactions of photosynthesis, also known as the Calvin cycle, primarily produce glucose. These reactions use energy from the light-dependent reactions to convert carbon dioxide and other compounds into glucose, which is a sugar that provides energy to cells. Thus, the main product of these reactions is not Oxygen, ATP, or NADPH, but Glucose.

What is the chemical formula for water?

• H2O

• CO2

• O2

• H2SO4

Answer explanation

The chemical formula for water is H2O. This is because water molecules consist of two hydrogen atoms and one oxygen atom. Therefore, the correct answer is H2O.

What is the primary role of chlorophyll in photosynthesis?

• It absorbs sunlight.

• It produces glucose.

• It releases oxygen.

• It breaks down water molecules.

Answer explanation

Chlorophyll in plants plays a critical role in photosynthesis, a process that allows plants to absorb energy from sunlight. The chlorophyll pigment absorbs light, particularly violet-blue and red light, and converts it into chemical energy which is then used for the plant's growth and development. Therefore, the primary role of chlorophyll in photosynthesis is to absorb sunlight.

What is the chemical formula for carbon dioxide?

• CO2

• H2O

• O2

• CH4

Answer explanation

The chemical formula for carbon dioxide is represented as CO2. This formula indicates that each molecule of carbon dioxide contains one carbon atom (C) and two oxygen atoms (O). Hence, the correct answer to the question is CO2.

What is the primary function of the roots in a plant?

• Absorption of water and nutrients

• Photosynthesis

• Production of fruits

• Production of flowers

Answer explanation

The primary function of roots in a plant is the absorption of water and nutrients. They act like straws sucking water and minerals from the ground. Photosynthesis is carried out by leaves, and the production of fruits and flowers is associated with the reproductive parts of a plant, not the roots.