AQA B2 plants

Brief overview of plants

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Carbon Dioxide + Water goes to with sunlight and chlrophyll glucose + oxeygen

Photosynthesis is the process that produces food in plants- glucose

Photosynthesis happens in leaves of all green plants, inside the chloroplasts found in the leaf and other green parts of the cell. Chloroplasts contain a substance called chlorophyll, which absorbs sungligh and uses its energy to convert carbon dioxide and water into gluce , oxygen is produced as a by-product.

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Things needed for photosynthesis

1. light

2. Chlorophyll

3. Carbon Dioxide

4. Water

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Rate of Photosynthesis

Three things can be the limiting factor; Carbon dioxide, light and temperature.

Limiting factor means that its stopping photosynthesis from happening at its optimum rate.

The factors depend on the enviromental conditions:

At night - LIGHT is going to be the limitting factor

In winter - its often the TEMPERATURE

If its warm enough and bring enough - then CARBON DIOXIDE is properly the limiting factor

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Artificial creation of ideal conditions for farmin

Most comman way of creating the ideal conditions is in a Greenhouse

They help to trap the sun's heat making sure temperature is not the limiting factor, In winter a heater made be kept in the greenhouse to keep temperature at optimum level.

In summer is could get too hot, shades and ventilation to cool the greenhouse down.

Light always needed for photosynthesis, commercial farmers often provide artifical light so plants can photosynthesise through the night.

Can also increase carbon dioxide levels often done by using a parrafin heater to heat the greenhouse as carbon dioxide is a by-product.

Keeping plants enclosed also means ut easier to keep them free from pests and diseases, farmers can add fertilisers to provide minerals for health growth without worry of spreading chemicals, greenhouse means you can reach optimum yield of crops

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How plants use Glucose

Respiration - Plants maufacture glucose in their leaves, they use some of the glucose for respiration, this releases energy which enables the rest of the glucose to convert into various other useful substances.

Making fruits - Glucose and Frutose both sugars are turned into Sucrose for storing in fruits

Making proteins - Glucose combined with nitrates make ammino acids which are then made into proteins

Stored in seeds - Glucose is turned into lipids (fats and oild) for storing in seeds, seeds also store starch

Stored at starch - Glusose is turned into starch and stored in roots, stems and leaves, ready for use when photosynthesis isn't happeneing. Starch is insoluble so doesnt bloat the storage cells by osmosis like glucose would.

Making Cell walls - Glucose is converted into cellulose for making cell walls, especially in rapildy growing plants

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Minerals For healthy Growth

Nitrates - Making amino acid which is then used to make protein

Mangesium - Make chlorphyll which is in turn needed for photosynthesis

Lack of nitrates - Deficent in nitrates the plants starts to show stunted growth, this is because proteins are needed for new growth and cant be made without nitrates

Lack of Magnesium - Deficency in magnesium causes the leaves of the plants to turn yello, because magnesium is needed to make chlrophyll which gives the leaves their green colour

If the plant is left short of minerals for long enough it may die.

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Is where just one type of crop is grown in the same place year after year.

All the plants are the same crop, so they need the same minerals this means the soil becomes defficent in the minerals that the crop uses.

Defficency in just one mineral is enough to cause poor growth and give a reduced yield

^^ Results in poor crops unless fertilizer is added to replenish the depleted minerals

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Managing Food Production

Efficency of food production can be improves.....

  • Reduce the number of stages in the food chain
  • Restrict the energy lost by Farm animals

Keep the animals close together indoors, in small pens so that they're warm and cant move about

This saves them Wasting energy on movement stops them giving out so much energy as heat. 

Makes tge transfer of energy from the animal feed to the animal more efficent - animals will grow faster  on less food

Makes things cheaper for the farmer and for the consumer

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Managing food production con ...

Involves comprimises and conflict

Animals living in unatural and uncomfortable conditions in cruel, there is a growing deamnd for organic meat which means the animal will not have been farmed by controlling itsenergy lost through movement.

Crowded condtions of factory farms create a favourable enviroment for the spread of diseases, to try and prevent diseases animals are given antibiotics, animals are then eaten by humans , allows microbes that infect humans to develop immunity to those antibiotics - antibiotics become less effective as a human medicine.

Enviroment where animals kept needs to be carefully controlled, animals need to be kept warm to reduce energy lost by heat means using fossil fuels to heat pens - expensive

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:) PurpleJaguar (: - Team GR


Good notes thanks

but loadsa spelling mistakes :L



really good notes 

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