B2.2 Organisms In The Environment Flashcards Preview

GCSE AQA Biology (old spec) > B2.2 Organisms In The Environment > Flashcards

Flashcards in B2.2 Organisms In The Environment Deck (19):

What four things do plants need to grow?

Carbon dioxide


What's the equation for photosynthesis?

Carbon dioxide + water -(light energy)-> oxygen + glucose


In words what actually happens during photosynthesis?

Light enemy is absorbed by the chlorophyll, a substance found in the chloroplasts. This energy is then used to convert carbon dioxide from the air and water from the soil into a simple sugar called glucose. Oxygen is also produced and released as a gas.


How do you test a leaf for starch?

Put a leaf in boiling water for a minute to soften it
Place a leaf into a test tube half full of ethanol
Place the test tube in hot water for 10 mins
Return the leaf to the hot water for a min
Spread the leaf out on a tile and cover it in iodine solution.
The iodine turns black in the presence of starch


What happens to photosynthesis as you increase the concentration of carbon dioxide?

The rate of photosynthesis increases until it levels off when co2 is no longer a limiting factor.


What happens to photosynthesis as you increase the temperature?

The higher the temperature, the quicker the rate of photosynthesis until the enzymes start to denature and the rate of photosynthesis decreases


What happens to photosynthesis as light intensity increases?

The more light intensity the quicker the rate of photosynthesis until there is no more light to be emitted.


What would you measure to determine how much photosynthesis is happening when light intensity is increased?

Amount of bubbles
More bubble more light intensity


What do plants do with the glucose they produce?

Used to provide energy for chemical processes in the cell (by respiration)
Turned into sucrose and transported to other parts of the plant
Turned into starch and stored in the cell as starch grains
In darkness the starch is changed back into glucose and transported out of the cell


What is glucose?

Small soluble molecule


What is starch?

Long chain of glucose, insoluble (doesn't dissolve in water)
Ideal for storage


How do plants store food?

They turn the glucose into an insoluble starch which makes it ideal and easy to store


What other materials do plants and algae need to make protein?

Potassium (helps the enzymes)


What happens to a monomer when polymerisation happens? Give an example.

Turns to a polymer
Glucose is a monomer and then it turns to starch which is a polymer


Where's cellulose found?

Plant cell walls


What physical factors affect organisms?

Light intensity
Amount of CO2 and O2


Give one way leaves are adapted for photosynthesis?

Leaves are thin for diffusion


What are transects?

They're tape measures put across a habitat. You then use quadrants at different points on the transects. It allows you to measure how the the habitat is changing along a period


Where would you throw a quadrat?

Have an area of land behind you and randomly throw it behind you so you don't get bias results ( you might biasedly pick an area with lots of flowers)