2217027
| Frage | Antworten |
| A population is all the organisms of one species in a habitat. | Population size= number in first sample X number in second sample / number in second sample previously marked |
| Populations of different species in a habitat make up a community. | population sizes can be estimated using a quadrat. 1. count all the organisms in a m² quadrat. 2. multiply the number of organisms by the total area (in m²) of a habitat. |
| Ecosystems are self-supporting. the only thing that's needed from outside the ecosystem is an energy source. (sun) | They contain almost everything they need to maintain themselves. Water, nutrients and esential elements like carbon all get recycled within the ecosystem. |
| An ecosystem is all the organisms in a particular area, as well as all the non-living (abiotic) conditions. e.g. temperature, salinity and soil quantity. | An ecosystem isn't the same as a habitat. A habitat is the place where organisms live. |
| Transects are used to investigate the distribution of organisms. Distribution is where organisms are found within a particular area. | To do a transect, you mark out a line using a tape measure and place quadrats next to each other all the way along the line. Then you count and record the organisms found in the quadrat. |
| The distribution of organisms is affected by abiotic factors. | Organisms are adapted to live in certain physical conditions. Many organisms can only survive in the conditions they're adapted to. |
| changes in abiotic factors can lead to zonation. | Zonation is the gradual change in the distribbution of species across a habitat. |
| Biodiversity is a measure of the variety of life in an area. what does it include? | 1: the amount of variation between individuals of the same species in an area. 2: the number of different species in an area. 3: the number of different habitats within an area. |
| Natural ecosystems have a higher biodiversity than artificial ones. say why and give examples of the two different ecosystems. | Natural ecosystems maintain themselves without any major interferance from humans. E.g. native woodlands and natural lakes. Artificial ecosystems are created an maintained by humans. E.g. forestry plantations and fish farms. |
| Population is a two stage process. what is the balanced symbol equation for this reaction? | |
| How do plants use glucose they make? | For: respiration making cell walls storing in seeds storing as starch making proteins |
| There are three limiting factors that control the rate of photosynthesis. What are they? | 1: Not enough light. This slows down the rate of photosynthesis. 2: Little carbon dioxide also slows it down. 3: Temperature. As the temperature increases, so does the rate. |
| Diffusion is the gradual movement of particles from an area of higher concentration to an area of lower concentration. | It happens in both liquids and gasses because the individual particles in these substances are free to move about randomly. |
| Name all the parts of a typical leaf. | Palisade & spongy mesophyll layer upper & lower epidermis vascular bundle waxy cuticle chloroplast guard cell air space stoma |
| Plants carry out both photosynthesis and respiration. Photosynthesis only happens in the day whereas respiration takes place in both day and night. | Plants exchange gasses by diffusion. Diffusion of gasses in the leaves is vital for both photosynthesis and respiration. |
| How are leaves adapted for efficient photosynthesis, diffusion and absorbtion of light? | Leaves are broad so there's a large surface area exposed to light where gasses can diffuse. They're thin- CO2 & H2O only have to diffuse a short distance to the photosynthesising cells. They have lots of stomata that let CO2 & O2 in & out. They have guard cells what control when the stomata opens and closes. Leaves have a big internal surface area to volume ratios. They contain chloroplasts which contain chlorophyll to absorb light energy. |
| What is osmosis? | The gradual movement of water molecules across a partially permeable membrane from a region of higher water concentration to a region of lower water concientration. |
| What are the two transport systems in plants and what do they do? | Phloem tubes- transport food (sugars) up & down the stem to growing & storage tissues. This is known as translocation Xylem vessles- take water up from the roots to the leaves in the transpiration stream. |
| What do the xylem & phloem run alongside each other in? | The vascular bundle. |
| What are the 3 examples of the xylems support? | Root cross-section: to stop roots crushing when they push through the soil. The xylem is in the centre to give it strength. Stem cross-section: stems need to resist bending. The xylem offers protection. Leaf cross-section: xylem & phloem work together to make a network of veins that support the leaves. |
| Transpiration is the loss of water from the plant. How can transpiration rates be increased? | An increase in light intensity. An increase in temperature An increase in wind A decrease in humidity |
| How does an increase in light intensity affect the rate of transpiration? | The brighter the light, the greater the transpiration rate. Stomata begin to close as it gets darker. As photosynthesis can't happen in the dark, they don't need to be open to let CO2 in. When the stomata are closed, water can't escape. |
| How does an increase in temperature affect the rate of transpiration? | The warmer it is, the faster transpiration happens. This is because the water particles have more energy to evapourate and diffuse out of the stomata in the warmth |
| How does an increase in air movement (wind) affect the rate of transpiration? | If there's lots of wind around a leaf, transpiration happens faster. If the air around a leaf is very still, the water vapour just surrounds the leaf & doesn't move away. This means there's a high concentration inside & outside the leaf so diffusion doesn't happen as quickly. If it's windy, there's a low concentration of water in the air outside the leaf. making diffusion happen quicker. |
| How does a decrease in humidity increase the rate of transpiration? | If the air around the leaf is very dry, transpiration happens quicker. If the air is humid there's a lot of water in it already. So the inside & the outside of the leaf is similar. Diffusion happens if there's a really high concentration in one place & a really low in the other. |
| What are the four main minerals plants need? | Nitrates- needed for cell growth. Phosphates- Needed for respiration & growth. Potassium- needed for photosynthesis & respiration. Magnesium- needed for photosynthesis. |
| Things decay because of microorganisms. What does the rate of decay depend on? | Temperature- speeds up respiration in microbes. Things decay faster (warm) Water- things decay faster when moist. Ocygen- Things decay faster when oxygen's available |
| Detrivores feed on dead & decaying material. Examples of detrivores are earthworms, maggots & woodlice. As they feed, they break it up into smaller bits. This gives a bigger surface area for smaller decomposers to work on and so speeds up decay. | Saphrophytes also feed on decaying material but they do so by extracellular digestion. Meaning they feed by secreating enzymes onto the material outside of their cells. The enzymes break down the material into smaller bits which can be absorbed by the saphrophyte. E.g. fungi. |
| Food preservation methods reduce the rate of decay. Name these methods. | Adding salt/sugar Adding vinegar Freezing Canning cooling drying |
| Intensive farming is used to produce more food from less land. How can farmers make the transfer of energy between organisms in a food chain more efficient? | Using herbicides to kill weeds- more energy from the sun goes to the crops. Using pesticides to kill insects that eat crops- no energy is transferred into other food chains. Battery farming animals- Saves energy on movement & warmth. |
| Hydrophonics is where plants are grown without soil. What are the advantages & disadvantages of this method? | Advantages- mineral levels can be controlled more accurately & diseases can be controlled more effectively. Disadvantages- lots of fertilisers need to be added & there's no soil to anchor the roots & support the plants. |
| What are the main effects of intensive farming? | 1: Removal of hedges to make bigger fields destroy the natural habitat of wild creatures & can lead to soil erosion. 2: Careless use of fertilisers can pollute rivers and lakes. (eutrophication) 3: pesticides disturb food chains 4: battery-farming is viewed as cruel. |
| What is biological control? | Using living things instead of chemicals to control pests. A predator, parasite or a disease could be used. |
| What are the advantages & disadvantages of biological control? | Advantages: No chemicals are used- less pollution-less disruption of food chains & less risk to people eating the sprayed food. Disadvantages: The predator introduced may not eat the pest, it could eat useful species, its population might increase & become uncontollable and the predator might not stay in the area wher it's needed. |
| Name 5 organic farming techniques. | 1: Varying seed planting times 2: Use of organic fertalisers 3: Biological control 4: Crop rotation 5: Weeding |
| Give examples of organic fertalisers and say what using them can do. | e.g. animal manure & compost. This method can recycle the nutrients left in plant & animal waste. It is good for the environment. |
| What is crop rotation and what can it do? | Growing a cycle of different crops in a field each year. This stops pests & diseases building up in one crop & stops nutrients from running out. |
| What is weeding? | physically removing weeds rather than spraying them with herbicide. This means no chemicals are involved. |
| What are the benefits of varying seed planting times? | Sowing seeds later or earlier in the season will help avoid the pests for that crop. This means the farmer won't have to use pesticides. |
| What are the advantages of organic farming methods? | 1: Organic farming uses fewer chemicals-less risk of toxins on food. 2: Better for the environment- less chance of polluting rivers with fertiliser & no pesticides are used. 3: No battery farming will take place due to ethical guidelines. |
| What are the disadvantages of organic farming? | 1: Takes up more space than intensive. 2: More labour intensive= expensive food. 3: Not as much food can be grown. |
Möchten Sie mit GoConqr kostenlos Ihre eigenen Karteikarten erstellen? Mehr erfahren.