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17 Cards in this Set
- Front
- Back
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What do plants make/contain? |
Startch |
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Things things needed for starch production by leaves? |
It uses carbon dioxide from the air It need light It needs chlorophyll in the leaves |
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What is another product made by plants during photosynthesis? |
Oxygen. |
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What is starch and how do plants make it? |
Composed of long chains of glucose. A plant does not make starch directly, but first produces glucose, which is then joined together in chains to form starch molecules. |
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What is the name of a carbohydrate made of many sugar sub-units? |
Polysaccharide |
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What is photosynthesis? |
plants use the simple inorganic molecules carbon dioxide and water, in the presence of chlorophyll and light to make glucose and oxygen. |
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What is the roll of chlorophyll? |
It is a green pigment that absorbs the light energy needed for the reaction to take place. The products of the reaction contain more energy than the carbon dioxide and water. |
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What adaptions are in the leaf to photosynthesis? |
Large surface area to absorb light Many chloroplasts containing chlorophyll, a supply of water and carbon dioxide, and a system for carrying away the products of photosynthesis to other parts of the plant. Leaves are thin, flat structures supported by leaf stalk which can grow to allow the blade of the leaf to be angled to receive the maximum amount of sunlight. |
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What are the functions of the two outer layers of the leaf cells? |
The two outer layers (the upper and lower epidermis) have few chloroplasts and are covered by a thin layer of a waxy material called the cuticle. This reduces water loss by evaporation, and acts as a barrier to the entry of disease-causing microorganisms such as bacteria and fungi. |
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What are stomata and what are their functions? |
The lower epidermis has many pores called stomata. Usually the upper epidermis contains fewer or no stomata. The stomata allow carbon dioxide to diffuse into the leaf to reach the photosynthetic tissues. They also allow oxygen and water vapour to diffuse out. Each stoma is formed as a gap between two highly specialised cells called guard cells, which can alter their shape to open or close the stoma. |
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What is the palisade layers? What is its function? |
In the middle of the leaf are two layers of photosynthetic cells called the mesophyll. Just below the upper epidermis is the palisade layer. This is a tissue made of elongated cells, each palisade cell are close to the source of light, and the upper epidermis is relatively transparent, allowing light to pass through to the enormous numbers of chloroplasts which lie below. |
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What is the spongy mesophyll layer? |
A tissue made of more rounded, loosely packed cells, with air spaces between them called the spongy layer. These cells also photosynthesise, but have fewer chloroplasts than the palisade cells. They form the main gas exchange surface of the leaf, absorbing carbon dioxide and releasing oxygen and water vapour. The air spaces allow these gases to diffuse in and out of the mesophyll. |
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What is the xylem? |
Water and mineral ions are supplied to the leaf by vessels in a tissue called the xylem. This forms a continuous transport system throughout the plant. Water is absorbed by the roots and passes ip through the stem and through the veins in the leaves in the transpiration area. In the leaves, the water leaves the xylem and supplies the mesophyll cells. |
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What is the phloem? |
The products of photosynthesis, such as sugars, are carried away from the mesophyll cells by another transport system, the phloem. The phloem supplies all other parts of the plant, so that tissues and organs that can't make their own food receive products of photosynthesis. the veins in the leaf contain both xylem and phloem tissue, and branch out again and again to supply all parts of the leaf. |
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What is the plant's use for glucose? |
Some glucose is used in respiration. Some glucose is turned to starch for storage. Plants convert glucose to fructose and sucrose, which is the main sugar carried out in the phloem. It can also be changed into another polymer called cellulose. |
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Which minerals are essential to plants? |
Nitrate ions are absorbed from the soil water, along with other minerals such as phosphate, potassium and magnesium ions. The element phosphorus is needed for the plant cells to make many important compounds including DNA. Potassium ions are required for enzymes in respiration and photosynthesis to work, and magnesium forms a part of the chlorophyll molecule |
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What are the four mineral ions needed in plants and uses? |
Nitrate - making amino acids, proteins, chlorophyll, DNA and many other compounds. Phosphate - Making DNA and part of cell membranes. Potassium - Needed for enzymes of respiration and photosynthesis to work. Magnesium - Part of chlorophyll molecule |
