Air and Photosynthesis Flashcards
Air is (1). It is made up of (2).
1) a mixture of gases
2) nitrogen, oxygen, carbon dioxide, noble gases, water vapour and small amounts of other gases.
The percentages of gases in the air:
Nitrogen: 78% Oxygen: 21% Noble gases: 0.9% Water vapour and other gases: 0.07% Carbon dioxide: 0.03%
Noble gases and nitrogen are (1).
1) unreactive gases
Facts about oxygen:
Colourless
Odourless
Burning splint test: burns more brightly
Glowing splint test: relights
Facts about carbon dioxide:
Colourless
Odourless
Colour change of hydrogencarbonate indicator: from red to yellow
Colour change of lime water: from colourless to milky
Hydrogencarbonate indicator is used to measure (1) and give different (2) at different (3).
1) carbon dioxide levels
2) colours
3) carbon dioxide concentrations
Colour of hydrocarbonate indicator to concentration of carbon dioxide:
> 0.03%: yellow
0.03% (normal level in air): red
<0.03%: purple
(1) is used to test for water and water vapour. (1) should be stored in a (2) which contains (3) to (4).
1) dry cobalt chloride paper
2) desiccator
3) chemicals
4) absorb moisture
Water and water vapour turn (1) from (2) to (3).
1) dry cobalt chloride paper
2) blue
3) pink
(1) plants can make their own food by (2). This process needs (3) to make food. (4) is also produced as a (5) in the process.
1) Green
2) photosynthesis
3) raw materials and an energy source
4) Oxygen
5) by-product
(1) and (2) are the raw materials for photosynthesis. (1) is (3) from the (4). (2) is (5) from the (6).
1) Carbon dioxide
2) water
3) obtained
4) air
5) absorbed
6) soil
Energy needed for photosynthesis comes from (1). The (1)(2) is absorbed by (3), a (4) in the (5) or (6). During photosynthesis, (1)(2) is (7) into (8)(2) in the (9) produced.
1) light
2) energy
3) chlorophyll
4) green pigment
5) chloroplasts of green leaves
6) other green parts of plants
7) converted
8) chemical
9) food
(1) is the food produced. The plants use (1) for (2). (1) that is not used immediately is (3) into (4) for (5). (4) can be (3) back into (1) for use later. Both (1) and (4) are (6).
1) Glucose
2) growth and respiration
3) converted
4) starch
5) temporary storage
6) carbohydrates
The word equation of photosynthesis:
carbon dioxide + water (reactants) —> glucose (product) + oxygen (by-product)
\
\
light energy absorbed by chlorophyll
Chemical equation of photosynthesis:
6CO2 + 6H2O —> C6H12O6 + 6O2
From the chemical equation, we can see that:
- carbon dioxide reacts with water to form glucose and oxygen.
- the total number of each atom (carbon atom, oxygen atom and hydrogen atom) is the same on both sides of the equation.
We (1) a plant carrying out photosynthesis. However, (2) can provide (3) of photosynthesis. If we can show from (2) that the plant has (4), we can confirm that photosynthesis has taken place.
1) cannot see
2) experiments
3) evidence
4) produced starch and oxygen
Procedures of starch test:
1) Remove a leaf from a potted green plant that has been placed in bright light for several hours.
2) Put the leaf into a beaker of boiling water for about two minutes. This destroys the cell membranes of the leaf cells.
3) Turn off the Bunsen burner. Use a pair of forceps to transfer the leaf to a boiling tube containing alcohol. Then, put the boiling tube into the beaker of hot water for about 10 minutes.
4) Use a pair of forceps to remove the leaf from the alcohol. Wash the leaf in the beaker of hot water for about 30 seconds. This removes the alcohol and makes the leaf soft.
5) Use a pair of forceps to take the leaf out of the hot water and carefully spread it on a white tile. Add a few drops of iodine solution to it.
We can use (1) to test for starch. (1) changes from (2) to (3) in the (4) of starch.
1) iodine solution
2) brown
3) blue-black
4) presence
In addition to starch, (1) is also produced in photosynthesis. We can use a (2) to show that the (3) given out by the plant is (1). If the (2)(3), the (3) given out by the plant is (1), (4) that photosynthesis has taken place.
1) oxygen
2) glowing splint
3) gas
4) indicating
Explanation for destarching a plant:
Destarching means placing a plant in the dark for at least 48 hours. During this period, all the starch stored in the plant is converted into glucose which is then used by the plant. This ensures that the plant does not contain any starch when the investigation begins. Any starch we detect later is formed during the investigation, indicating that photosynthesis has taken place.
What is soda lime used for?
Absorbing carbon dioxide.
Photosynthesis is an (1). It allows plants to (2). On the other hand, (3) cannot (2). Some (3) feed on plants and other (3) feed on (3). Therefore, photosynthesis is important in (4). Photosynthesis also helps (5) in Nature.
1) essential life process
2) make their own food
3) animals
4) providing food directly or indirectly for living things
5) maintain the balance of oxygen and carbon dioxide
Plants can (1) by (2). They are called (3). Animals cannot (4). They (5). They are called (6). The (7) among (8) can be shown by a (9).
1) make their own food
2) photosynthesis
3) producers
4) produce food on their own
5) feed on plants or other animals
6) consumers
7) feeding relationship
8) living things
9) food chain
