Photosynthesis

Plant make food by absorbing water and carbon dioxide. Which of the following substances is the origin of oxygen released as gas by green plants during photosynthesis?

• Water

• Sugar

• Carbon dioxide

• Ribulose – 1,5-biphoshate

Answer explanation

Oxygen is released during the light reactions of photosynthesis. Water, or H₂O, is split during the light reactions into gaseous oxygen, or O₂,

Oxygen and carbon dioxide are gasses that cycle out in the ecosystem.

Which of the following gasses is important to photosynthesis?

• Ozone gas

• Water vapor

• Oxygen

• Carbon dioxide

Answer explanation

To perform photosynthesis, plants need three things: carbon dioxide, water, and sunlight. for photosynthesis. Carbon dioxide enters through tiny holes in a plant's leaves, flowers, branches, stems, and roots.

Plants are considered as food manufacturers. In which of the following cell organelles does photosynthesis occur?

• Ribosome

• Chlorophyll

• Chloroplast

• Mitochondrion

Answer explanation

In plants, photosynthesis takes place in chloroplasts, which contain the chlorophyll.

Photosynthesis is made up of complex processes. Which of the following are the end products of photosynthesis?

• Water and oxygen

• Carbon dioxide and water

• Water and carbon dioxide

• Glucose and oxygen

Answer explanation

Photosynthesis is a complex process that plants use to produce glucose and oxygen from carbon dioxide and water.

Oxygen and carbohydrate Consumers are mostly dependent on photosynthetic providers. In which of the following products of photosynthesis is the chief source of energy for most organisms?

• Glucose

• Maltose

• Oxygen

• Sucrose

Answer explanation

During the process of photosynthesis, cells use carbon dioxide and energy from the Sun to make sugar molecules and oxygen. These sugar molecules are the basis for more complex molecules made by the photosynthetic cell, such as glucose

Plants obtain water for photosynthesis through _______.

• xylem of roots

• phloem of roots

• stomata of leaves

• lenticels of stem

Answer explanation

The water required by the plants of photosynthesis is observed by the roots of the plants from the soil through the process of osmosis. The water absorbed by the roots of the plant is transported upward through the xylem vessels to the leaves

The light-dependent reaction of photosynthesis must come first before the light-independent reaction because its products are important to the fixation of carbon dioxide (CO₂). Which of the following enable is/ are products of the light-dependent reaction?

• ADP only

• ATP only

• NADPH only

• NADPH and ATP

Answer explanation

Light-dependent reactions, which take place in the thylakoid membrane, use light energy to make ATP and NADPH.

The primary function of stomata is to

• minimize water loss

• facilitate gas exchange for photosynthesis

• signal guard cells to open or close

• convert sunlight into usable energy

Answer explanation

The stomata allow the exchange of gases (CO₂ and O₂) with the atmosphere. Evaporation of water from the leaf surface occurs through the stomata. Thus, the stomata help in the process of transpiration.

____________ are small discs found within the chloroplast that contains components important for photosynthesis.

• Carotenoid

• Lamella

• Thylakoid

• Stroma

Answer explanation

Chloroplasts contain disc-shaped structures called thylakoids, which contain the pigment chlorophyll. Chlorophyll absorbs certain portions of the visible spectrum and captures energy from sunlight.

Producers are considered as the primary food manufacturers in the planet.

Which of the organisms are capable of photosynthesis?

• plants only

• plants and algae only

• plants and some bacteria only

• plants, algae, and some bacteria only

Answer explanation

Plants, algae, and a group of bacteria called cyanobacteria are the only organisms capable of performing photosynthesis, Because they use light to manufacture their own food, they are called photoautotrophs