Ecosystems Flashcards
What is the difference between animals and plants?
Their cells have different components ad structures.
Plants cannot move on their own where as animals have freedom of movement
Plants make their own food where as animals eat plants or other animals.
Consumers vs Producers
Consumers
Unable to make their own food and will therefore eat plants or animals to survive, these products are broken down during digestion. Examples: Tiger, horse, mouse, snail.
Producers
Convert materials using sunlight energy into glucose which they use as source for respiration. They perform photosynthesis. Examples: Plants, algae and some bacteria.
Algae
Algae is unique in that it is difficult to classify the organism as either plant or animals due to its cellular structure.
Algae can be unicellular or multicellular
They live in the water
They do not have roots, leaves, stems etc.
What is photosynthesis?
As plants do not eat food they need to produce their own food through photosynthesis. To do this they use carbon dioxide which is take in from the air, water which is absorbed by the roots and sunlight energy.
A chemical reaction called photosynthesis takes place and they produce oxygen which is a waste product and released into the atmosphere as well as glucose which is then stored in the plant as starch.
Carbon Dioxide (Co2) + Water (H2O) —L—I—G—H–T–> Glucose (C6H12O6) + Oxygen (O2).
Chloroplasts
Photosynthesis takes place in the chloroplasts within a plant cell. Chloroplasts contain chlorophyll which is normally green, this, in turn, causes the plant to have a green colour.
How does water and oxygen enter the plant?
Water enters a plant through osmosis (the passive diffusion of water across a membrane) Most water enters the plant through the root hair cells.
Oxygen enters the plant with carbon dioxide through the stomata. Aerobic respiration occurs in the mitochondria then oxygen is expelled back through the stomata with water vapour.
Does a plant photosynthesise at night? why?
Traditionally plants do not photosynthesise at night unless they are provided with an artificial light source with a corresponding wavelength. However, at night plants uptake oxygen and release carbon dioxide this is because respiration can always take place, unlike photosynthesis.
Can the root hair cells of a plant photosynthesise? why?
Root hair cells are where most water absorption happens. This means they have a large surface area but this does not mean they can photosynthesis; this is because root hair cells do not have chloroplasts.
How do plants with red leaves survive?
Chlorophyll absorbs light in the red part of the light spectrum therefore this light energy can still be transferred to Glucose.
Plant minerals
Whilst plants are able to make their own food through photosynthesis, they also need to absorb
minerals from the soil. These minerals are
vital for the production of chlorophyll and the
growth of the plant.
If a plant is unable to access essential minerals it can have a mineral deficiency.
Chlorophyll contains a green pigment called chlorophyll, but to make this pigment the chloroplasts must have certain minerals and energy.
What is a Nitrate deficiency?
Plants absorb nitrates in water through their roots.
Nitrates are present in high levels in fertilizer
NItrate deficiency is typically caused by sandy / well-drained soils however it can also be caused by excessive irritation, lack of soil and overwatering.
Symptoms include:
The whole plant appears pale, yellowish-green.
Early senescence (deterioration) of older leaves
Increased root growth
As a result, stunted shoot growth in a low shoot/root ratio.
Treatment:
Adding composted material; fertiliser to soil.
Planting a green manure crop such as borage
Planting nitrogen-fixing plants like peas or beans
Adding coffee grounds to the soil
What is a phosphate deficiency?
Phosphate is required for healthy roots, without phosphate they will lack growth. Additionally, young leaves on the plant will turn purple. Phosphate allows plants to regenerate starch storage and an excessive build-up can cause the leaves to turn purple.
What is potassium deficiency?
Required for healthy leaves and flowers and a deficiency will cause the leaf to turn yellow and curl in on itself. Potassium is used during photosynthesis and is a growth regulator within the plant.
What is a magnesium deficiency?
Magnesium is important for plants as it allows for the production of chlorophyll within the plant. If the plant is unable to make chlorophyll the plant will lose its green colour and start to turn yellow. This can contribute to the loss of leaves.
What is chemosynthesis
Chemosynthesis - Using a series of chemical
reactions to make food (glucose) instead
of using light as an energy source.
Chemosynthesis is a process whereby organisms can make glucose through a variety of chemical reactions. It was discovered in 1890 during research on bacteria. We have now developed deep-sea diving vessels that explore the deep ocean floor. These are expensive as they need to withstand the huge pressures under the ocean.
However, through increasing knowledge of life in the deep oceans, scientists are beginning to realise just how important chemosynthesis is. Chemosynthesis has shown us that the whole ecosystem can be built up from small organisms that live without sunlight. Space scientists are interested in learning more about chemosynthesis.
Chemosynthesis is only carried out by some types of bacteria. They use chemical reactions to make glucose. There are different groups of bacteria that use different types of chemical reactions:
1 sulfur bacteria – the breakdown of hydrogen sulfide
2 iron bacteria – reactions of iron compounds
3 nitrogen bacteria – conversion of ammonia to nitrates
4 hydrogen bacteria – reaction of hydrogen to form water
Sulfur bacteria are common in deep-sea volcanic vents and mud pots in volcanic areas on land. They react hydrogen sulfide with carbon dioxide, producing glucose, water, and sulfur. The energy from the breakdown of hydrogen sulphide is transferred to the chemosynthesis reaction, as there is no light for photosynthesis.
They are producers in the deep ocean. This means that chemosynthesis is the starting point of deep-sea food chains. Scientists are interested in these organisms as they live in environments with high temperature and pressure and their enzymes still function. Usually, enzymes would stop functioning above certain temperatures. We extract their enzymes to use in industrial reactions.
There are many other organisms that live around deep-sea volcanic vents. One of them is the tubeworm. They are consumers. They are interesting because they do not have a stomach so do not digest any food. They have developed a co-existence with the chemosynthetic sulfur bacteria. The bacteria live in a special organ inside the tubeworms. A type of tubeworm this occurs in is the Pompeii worm (Alvinella pompejama).
The bacteria produce glucose by chemosynthesis. The tubeworm then obtains some of this glucose for its food. In return, the bacteria have a secure place to live. This system of living together, with benefits for both organisms, is called mutualism. The relationship between the tubeworm and the bacteria is called symbiotic.
