Biology Ka2 Flashcards
What are chloroplasts?
Green discs that allow the plant to make food by photosynthesis
What do the roots of a plant do?
Take up water and minerals, keeps the plant
What are the different leaf adaptations?
- large surface area for absorbing light
- contain chlorophyll and chloroplasts to absorb light energy
- Air spaces to allow CO₂ to get to the cells and oxygen to leave them by diffusion
- veins to bring water to leaf cells
What is the function of a root hair cell?
Absorb water
What is the function of the xylem vessels?
They transports water
Name two uses of water
Photosynthesis and keeps the plant the rigid
Name do jobs of the stem
- support leaves
* Carry water to leaves
Which plant organ does water leave from?
The leaves
What do plants need for photosynthesis?
Carbon dioxide and water
How does the stomata help with gas exchange?
Small holes on the under side of the leaf that open and close to allow air into the leaf spaces
What is algae?
Algae are aquatic organisms that are adapted to photosynthesise in water by absorbing CO₂ dissolved in the water around them
Why do all organisms need food?
For respiration, growth and reproduction
Which part of the plant does photosynthesis happen in?
The leaves
How to plants photosynthesise?
Energy is transferred from the environment to the chloroplasts by light, it is then transferred to convert Co₂ from the air, plus water from the soil into a sugar called glucose, oxygen is released as a by product for us to breathe
Why is photosynthesis an endothermic reaction?
Because it needs an input of energy from the environment
What is the word equation for photosynthesis?
Carbon dioxide + water –> glucose + oxygen
What is the chemical equation for photosynthesis?
6Co₂ + 6H₂O –> C₆H₁₂O₆ + 6O₂
What happens to the energy transferred from the environment?
The energy transferred from the environment when the bonds holding CO₂ and H₂O together are broken. The energy transferred back to the environment with the formation of new bonds in glucose and oxygen
What do all of the leaf adaptations do?
Allow maximum amount of the photosynthesis to take place
Carbon dioxide joins with _____ to make ______ and _______
Water, glucose, oxygen
Why do plants grow faster in the summer?
Because they need warmth and CO₂ if they are going to photosynthesise and grow
What factors affect the rate of photosynthesis?
Light, temperature and carbon dioxide concentration
How does light effect the rate of photosynthesis?
The more light the more a plant can photosynthesise and grow faster
How does temperature effect the rate of photosynthesis?
As the temperature rises, the rate of photosynthesis increases. Photosynthesis is controlled by enzymes. Most are denatured at around 40-50’c. If the temperature is too high, the rate of photosynthesis will decrease
How does carbon dioxide level effect the rate of photosynthesis?
Plants need CO₂ to make glucose. The atmosphere is only 0.04% CO₂ which limits the rate of photosynthesis.
What happens if the chlorophyll in a leaf is limited?
Less photosynthesis will take place
How do plants help us live? W
Photosynthesis puts oxygen into the atmosphere for us to live on
What do plants make?
Complicated molecules such as carbohydrates, fats and proteins. They also make simple molecules such as CO₂ and H₂O using energy from the sun
