Work Sheet

Question 1

What is photosynthesis?

Answer 1

Photosynthesis is the process by which plants manufacture carbohydrates from raw materials using energy from light.

Carbon dioxide + water + sunlight -> glucose + Oxygen
6CO₂ + 6H₂O + sunlight -> C₆H₁₂O₆ + 6O₂.

Question 2

What is the chemical equation for photosynthesis?

Answer 2

The chemical equation for photosynthesis is: 6CO₂ + 6H₂O + sunlight -> C₆H₁₂O₆ + 6O₂.

Question 3

What is chlorophyll used for in photosynthesis?

Answer 3

Chlorophyll is a green pigment found in chloroplasts that transfers energy from light into energy in chemicals for the synthesis of carbohydrates. It is essential for photosynthesis to occur.

Question 4

How are carbohydrates produced in photosynthesis used?

Answer 4

Carbohydrates produced can be converted into starch for energy storage, cellulose for cell walls, used in respiration for energy, converted to sucrose for transport, or as nectar to attract pollinators.

Question 5

What other forms can carbohydrates take in plants?

Answer 5

Carbohydrates can be converted into lipids for energy in seeds and into amino acids when combined with nitrogen and other mineral ions absorbed by roots.

Question 7

What are the key adaptations of plant leaves for photosynthesis?

Answer 7

Most plant leaves have a large surface area and are thin, which helps limit water loss, absorb light energy, and allow for efficient gas exchange.

Question 8

What is the role of chloroplasts in photosynthesis?

Answer 8

Chloroplasts are where photosynthesis occurs and contain chlorophyll, which absorbs light energy and converts it to chemical energy.

Question 9

What is the function of the cuticle in plant leaves?

Answer 9

The cuticle is a clear waxy layer that surrounds the leaf, providing waterproofing and reducing water loss without reducing light absorption.

Question 10

What are stomata and their function?

Answer 10

Stomata are located on the lower side of the leaf, allowing carbon dioxide in and water vapor and oxygen out by diffusion.

Question 11

How do guard cells regulate water loss?

Answer 11

Guard cells surround the stomata and can control their opening and closing to limit water loss; they close the stomata when water supply is limited.

Question 12

What is a consequence of stomata closing due to limited water?

Answer 12

Closing the stomata reduces the diffusion of carbon dioxide for photosynthesis, which can make carbon dioxide a limiting factor and reduce the rate of photosynthesis.

Question 13

What is the palisade mesophyll?

Answer 13

The palisade mesophyll is a layer of cells in the leaf that contains many chloroplasts and is responsible for absorbing light.

Question 14

What is the spongy mesophyll?

Answer 14

The spongy mesophyll is a layer of tissue in the leaf that contains air spaces, allowing for gas exchange.

Question 16

What is photosynthesis?

Answer 16

Photosynthesis is the process by which plants convert light energy into chemical energy.

Plants in hot places often have fewer stomata to reduce water loss.

Question 17

How do some plants like cacti manage water loss?

Answer 17

Cacti only open their stomata at night to reduce water loss.

Question 18

What is the function of the upper and lower epidermis in leaves?

Answer 18

The epidermis acts as a protective barrier around the leaf to prevent pathogens from entering.

Epidermis cells are transparent to let light pass through and do not contain chloroplasts.

Question 19

Where are palisade mesophyll cells located and what is their function?

Answer 19

Palisade mesophyll cells are positioned near the top of the leaf to absorb light energy efficiently.

Question 20

What adaptations do palisade mesophyll cells have?

Answer 20

Palisade cells contain many chloroplasts for photosynthesis and have gaps between them for gas exchange and osmosis.

Question 21

What is the role of spongy mesophyll in leaves?

Answer 21

Spongy mesophyll has air spaces that increase surface area and allow rapid diffusion of CO2, water, and oxygen.

Question 22

What are vascular bundles?

Answer 22

Vascular bundles form the plant’s transport system, consisting of xylem and phloem.

Question 23

What is the function of xylem?

Answer 23

Xylem transports water from the roots through transpiration.

Question 24

What is the structure of xylem?

Answer 24

Xylem is made from hollowed-out dead cells with thick cell walls for structural strength and thin walls for capillary action.

Question 25

What is the function of phloem?

Answer 25

Phloem transports sugars and food nutrients in translocation.

Question 26

What adaptation do phloem cells have?

Answer 26

Phloem cells are made of living cells and have no nucleus.

Question 28

What is the importance of nitrate ions to plants?

Answer 28

Nitrate ions are used by the plant to build amino acids, and thus proteins and enzymes. Without nitrate ions, the plant would not be able to grow or repair itself.

Question 29

What role do magnesium ions play in plants?

Answer 29

Magnesium ions are used to make chlorophyll. A lack of magnesium ions will lead to a lack of chlorophyll, meaning that photosynthesis cannot occur. This results in insufficient energy for the plant to grow.

Question 30

What are the consequences of a lack of nitrate or magnesium ions?

Answer 30

The lack of either of these ions leads to yellow leaves and poor growth, eventually resulting in the plant's death.

Question 31

What is a limiting factor in photosynthesis?

Answer 31

A limiting factor is the factor that is least available to the plant, which limits the rate of photosynthesis.

Question 32

How does light intensity affect the rate of photosynthesis?

Answer 32

As light intensity increases, the rate of photosynthesis also increases. However, very high light intensity can lead to overheating, making temperature the limiting factor.

Question 33

How does carbon dioxide concentration affect photosynthesis?

Answer 33

As carbon dioxide concentration increases, the rate of photosynthesis also increases.

Question 34

How does temperature affect photosynthesis?

Answer 34

Photosynthesis requires enzymes that have an optimum temperature, usually about 25°C. At low temperatures, photosynthesis slows due to low enzyme activity, while at high temperatures, enzymes denature, also slowing the rate.