B3-living togther-food and ecosystems

Question 1

what’s the equation for photosynthesis?

Answer 1

carbon dioxide + water -> glucose + oxygen.
6CO2(g) + 6H20(l) -> C6H12O6(aq) + 6O2(g)

Question 2

what’s the first stage of photosynthesis?

Answer 2

needs light, water molecules are split into hydrogen and oxygen.
the oxygen is released from the plant into the air.

Question 3

what’s the second stage of photosynthesis?

Answer 3

hydrogen is combined with carbon dioxide from the air to make glucose.

Question 4

what is chloroplast?

Answer 4

-contain chlorophyll (a pigment that absorbs light and splits water into hydrogen and oxygen in the first stage.
-stores starch grains.

Question 5

what are enzymes?

Answer 5

-biological catalysts that speeds up a chemical reaction.
-they break down large molecules and help smaller molecules join together.
-they are proteins made up of long chains of amino acids.

Question 6

how do enzymes work?

Answer 6

-has an active site.
-only the correct substrate fits.
-reaction takes place at active sites.
-enzyme isn’t permanently changed and can be used again.

Question 7

what are enzymes limiting factors?

Answer 7

-temperature.
-light intensity.
-CO2 concentration.

Question 8

what’s the inverse square law?

Answer 8

the relative light intensity at any distance from a light source is inversely proportional to the square of the distance from the light source.

Question 9

what’s diffusion?

Answer 9

-molecules spreading out.
-high concentration to low.
-passive process (doesn’t need more energy).

Question 10

how’s diffusion used in a plant?

Answer 10

-CO2 diffuses through the stomata and into cells in the leaf to supply photosynthesis.
-oxygen diffuses out of the cells and through the stomata.

Question 11

what’s osmosis?

Answer 11

-water molecules moving by diffusion.
-partially permeable membrane.
-high concentration to low.

Question 12

how’s osmosis used in plants?

Answer 12

-root hair cell is adapted to increase the amount of water absorbed.
-osmosis drives the uptake of water by plant roots and determines how water passes from 1 cell to another throughout the whole plant.

Question 13

what’s active transport.

Answer 13

-moves nitrate from soil into roots.
-low concentration to high.
-energy is required to transport molecules across the cell membrane.

Question 14

what’s the xylem?

Answer 14

-transports water and minerals.
-moves from the roots up the stem to leaves and flowers.
-found in the stem and root.
-made from dead cells.
-impermeable walls making them tough.

Question 15

what’s the phloem?

Answer 15

-where sugars, amino acids and others are transported.
-can move up and down.
-found in the stem and root.
-made of living cells.
-has cyctoplasm.
joined end to end by a tube.

Question 16

what’s transpiration?

Answer 16

-water diffusing into the atmosphere through the stomata.
-it pulls water through the plant.

Question 17

describe the rate of water intake.

Answer 17

-is affected by environmental factors like temperature, air movement and light intensity.
-rate increases when these factors do.

Question 18

what’s translocation?

Answer 18

-transports substances like sugars.
-starts at the source (leaves).
-sugars are moved into the phloem through active transport,water is then drawn into the phloem by osmosis.
-sugar is unloaded at the root,stems and flowers, where it’s needed for cellular respiration and growth.

Question 19

what’s glucose?

Answer 19

-makes lipids, proteins and carbs.
-they are broken down by cellular respiration, this transfers energy between stores, making it available for life processes such as chemical reactions.

Question 20

describe the different tropic levels.

Answer 20

1: producer, autotroph, makes own food.
2: consumer, heterotroph, can’t make own food.
3: secondary consumers, carnivores/omnivores, eat primary consumers.
4: tertiary, carnivores etc, eat secondary consumers, top of the food chain.

Question 21

what’s the equation for biomass efficiency?

Answer 21

average in higher
————————- x 100
average in lower

Question 22

what’s the equation for the rate of decomposition?

Answer 22

change in mass
———————-
number of days