| What is respiration needed for? | Growth.
Movement.
Regulating body temperature.
To make large molecules from small molecules |
| What is the stomata? | Pores on the underside of a leaf that allow gas exchange. |
| What is respiration needed for? | Growth.
Movement.
Regulating body temperature.
To make large molecules from small molecules |
| What is respiration needed for? | Growth.
Movement.
Regulating body temperature.
To make large molecules from small molecules |
| What is respiration needed for? | Growth.
Movement.
Regulating body temperature.
To make large molecules from small molecules |
| What is respiration needed for? | Growth.
Movement.
Regulating body temperature.
To make large molecules from small molecules |
| What is respiration needed for? | Growth.
Movement.
Regulating body temperature.
To make large molecules from small molecules |
| What is respiration needed for? | Growth.
Movement.
Regulating body temperature.
To make large molecules from small molecules |
| What is photosynthesis? | An endothermic chemical reaction that uses light to change carbon dioxide and water, into glucose and oxygen and (ATP) energy. |
| What is the equation for photosynthesis? | Carbon Dioxide + Water → Glucose + Oxygen
6CO₂ + 6H₂O → C₆H₁₂O₆ + 6O₂ |
| What are the 5 main ways plants use glucose? | Respiration;
To make cellulose (plant cell walls);
To make amino acids (glucose is combined with nitrate ions - making proteins);
To store it as oil or fats;
To store it as starch (in the roots, stems, and leaves for when photosynthesis isn't happening, like in the winter). |
| What is a limiting factor? (photosynthesis) | Something that prevents photosynthesis from happening because there isn't enough of it. |
| What 3 limiting factors of photosynthesis? | Light (at night), CO₂ concentration (when it's warm and bright enough) and temperature (when its winter). |
| How is light a limiting factor of photosynthesis? | Light provides the energy needed for photosynthesis. It will rise directly proportional to the light because the photons (light) are directly hitting the chloroplast. |
| How is CO₂ concentration a limiting factor of photosynthesis? | CO₂ is a reactant in photosynthesis which is why it's needed. . It will rise directly proportional to the CO₂, however, it can level off and be limited if there's a limitation of light or temperature. |
| How is temperature a limiting factor of photosynthesis? | Temperature affects all chemical reactions because enzymes are involved. As temperature increases, so does the rate of photosynthesis, however, if it gets too high, the enzymes will denature (45°C), and the rate o photosynthesis will plummet. |
| What does this graph show about the relation of the limiting factors? | It shows that both lines level off when light is no longer the limiting factor.
The line at the higher CO₂ concentration of 0.4% levels off at a higher point than at 0.04%. this means CO₂ concentration must have been a limiting factor since it isn't temperature because it's the same for both lines. |
| What is the waxy cuticle? | A layer of wax on the upperside of the leaf. |
| What is the upper epidermis? | Thin cells that allow light to pass through. They also produce the waxy cuticle. |
| What is the palisade mesophyll? | Deep and tightly packed cells with lots of chloroplast for photosynthesis. |
| What is the spongy mesophyll? | Cells with gaps in between them for the diffusion of gases. |
| What is the lower epidermis? | Cells that have holes called stomata for gas exchange. |
| What are guard cells? | Cells that change shape due to osmosis. They become turgid (open) or flaccid (close). |
| What does the xylem carry? | Water and minerals. |
| What are some adaptions of the xylem? | They have dead cells (prevents water absorption).
They have lignin (makes it stronger).
No cytoplasm.
Hollow tube. |
| What and which direction does the xylem carry substances? | One direction, from the roots to the leaves. |
| How is the xylem and phloem arranged in leaves? | Vascular bundles. |
| What ion prevents plants from rotting? | Magnesium. |
| What does the phloem carry? | Sugars. |
| Whats the process that the phloem uses to carry substances? | Translocation is the movement of sugars through the whole plant. |
| What are some adaptions of the phloem? | Cytoplasm connects cells.
Made of living cells.
Cells have sieve plates which allow sugars and amino acids to flow easily through. |
| Why and where are the phloem and xylem arranged in vascular bundles? | In the stem to resist compression and bending. |
| Why and where is the phloem arranged in the centre with the xylem around it? | In the roots to withstand forces that can pull the plant out of the ground. |
| What are aphids? | Bugs that pierce the phloem to get to the glucose for respiration. |
| How do aphids cause problems for plants? | It reduces growth because there is less glucose available for respiration and the creation of large molecules. The aphid can also inject pathogens into the plant. |
| What is the process called where water moves through and out of a plant? | Transpiration |
| What is transpiration? | The evaporation of water from the stomata causes a pull since water moves up from the roots and through the xylem to replace it. This creates a repeating process called the transpiration stream. |
| How do guard cells open? | They become turgid. This is because it has plenty of water, causing the cells to swell and curve away from each other. |
| How do guard cells close? | They become flaccid. This is because the cell is lacking in water, so it relaxes and closes the stomata. |
| What can affect the transpiration? | Temperature, wind intensity, humidity, and light intensity. |
| How does temperature affect transpiration? | HIgh temperature means more water will evaporate, increasing transpiration rate. |
| How does wind intensity affect transpiration? | High wind intensity means that any evaporated water will be carried away by the wind, meaning that there will be a large concentration gradient, increasing transpiration. |
| How does humidity affect transpiration? | A low humidity means that there not much water particles in the air, meaning that there will be a large concentration gradient, increasing transpiration. |
| How does light intensity affect transpiration? | A high light intensity will increase photosynthesis, which means that the stomata will be opened for gas exchange and water will be able to escape. |
| What is the stomata? | Pores on the underside of a leaf that allow gas exchange. |
| What is the inverse square law? | Light intensity is inversely proportional to the squaue of the distance from the source.
I = 1/d²
I = light intensity (a.u)
d = distance (m) |
| Calculate the light intensity when the light is 20cm from the plant. | I = 1/d²
→ 20 cm = 0.2m
→ 1/0.2²
= 25 arbitrary units (a.u) |
| What is respiration needed for? | Growth.
Movement.
Regulating body temperature.
To make large molecules from small molecules |
| What is oxygen dept? | The amount of extra oxygen needed to oxidise lactic acid in the liver. |
| What is recovery time? | The amount of time it takes for to oxide lactic acid in the liver. |
| What type of energy is produced by aerobic respiration? | ATP. |
| What are some bodily changes when you exercise? | Fatigue.
Build up of lactic acid.
Increased breathing rate.
Increased heart rate.
Increased breath volume. |
| What are some examples of metabolic reactions? | Respiration.
Photosynthesis.
Converting glucose to starch, glucose or cellulose.
Forming lipid molecules.
Breaking down proteins from urea in the liver.
Using glucose and nitrate ions to form amino acids. |
| What are catabolic reactions? | The breaking down of complex molecules into smaller molecules. This releases energy (heat). |
| What are anabolic reactions? | The building of molecules the body needs. THis requires energy. |
| What is metabolic waste? | Substances that are produces from chemical reaction that may be toxic at high levels. |
| What are some examples of metabolic waste? | Carbon dioxide, urea and lactic acid. |
| How is urea removed? | It's filtered out by our kidneys into urine. |
| What are some factors that can affect mentabolism? | Age, gender, genetics, body mass and exercise. |
