Year 10A Photosynthesis Revision Flashcard

Front

Complete the photosynthesis equation: Water + Carbon dioxide --> ?

Back

Glucose + Oxygen

Answer explanation

The correct photosynthesis equation is Water + Carbon dioxide --> Glucose + Oxygen. This process occurs in plants, where they convert water and carbon dioxide into glucose and oxygen using sunlight.

Front

Photosynthesis is an __________ process requiring energy to start.

Back

endothermic

Answer explanation

Photosynthesis is an endothermic process because it requires energy, primarily from sunlight, to convert carbon dioxide and water into glucose and oxygen. This energy input distinguishes it from spontaneous reactions.

Front

Layer of leaf where most photosynthesis occurs:

Back

Palisade mesophyll

Answer explanation

Most photosynthesis occurs in the palisade mesophyll layer of the leaf, as it contains tightly packed chloroplasts that capture sunlight efficiently, making it the primary site for this process.

Front

Leaf layer important for gas exchange

Back

Spongy mesophyll

Answer explanation

The spongy mesophyll contains air spaces that facilitate gas exchange, allowing carbon dioxide to enter and oxygen to exit the leaf. This layer is crucial for photosynthesis and respiration in plants.

Front

Adaptation of leaf for light absorption in photosynthesis:

Back

Transparent cuticle and epidermis

Answer explanation

The transparent cuticle and epidermis allow light to penetrate the leaf, facilitating photosynthesis. In contrast, few chloroplasts, tightly packed cells, and a thick waxy cuticle would hinder light absorption.

Front

Adaptation for gas diffusion in photosynthesis:

Back

Intercellular air spaces

Answer explanation

Intercellular air spaces facilitate the diffusion of gases, such as carbon dioxide and oxygen, necessary for photosynthesis. This adaptation allows for efficient gas exchange within the leaf.

Front

Why boil a leaf in ethanol?

Back

To remove chlorophyll

Answer explanation

The leaf is boiled in ethanol to remove chlorophyll, which allows for easier observation of other components, such as starch, during subsequent tests. This step is crucial for distinguishing the presence of starch in the leaf.

Front

Why is the leaf boiled in water?

Back

To soften the leaf

Answer explanation

The leaf is boiled in water to soften it, making it easier to test for starch later. This process helps break down the cell walls, allowing for better access to the starch stored in the leaf.

Front

Iodine is added to leaves to test for starch.

Back

Test for starch

Answer explanation

Iodine is added to the leaf to test for starch. When iodine comes into contact with starch, it turns blue-black, indicating the presence of starch stored in the leaf.

Front

Destarching a plant before photosynthesis:

Back

Place in the dark for 48 hours.

Answer explanation

To destarch a plant before a photosynthesis experiment, it should be placed in the dark for 48 hours. This prevents photosynthesis, allowing the plant to use up its stored starch, ensuring accurate results in the experiment.