B2 Ecosystems Flashcards
What is a producer
(Plants and algae)
Something that makes it’s own food
What are consumers
Animals that eat other organisms to survive
How do producers make their own food
Converting materials found in their environment into glucose, a carbohydrate, using sunlight
What is photosynthesis
The chemical reaction in which I pants take in carbon dioxide and water and change then into glucose providing the plant with food
What is the word equation for photosynthesis
Carbon dioxide + water —> glucose + oxygen
Where does photosynthesis mainly occur
In the chloroplasts in the leaf cells - though a small amount happens in the stem
How does photosynthesis work
The plant takes in carbon dioxide through tiny holes in the leaf. Water is collected through the grind and root hair cells. The sunlight is absorbed by the chlorophyll then the reaction occurs and the products glucose and oxygen are left
How does water get into a plant
It diffuses into the root hair cells and transported around the plant in xylem tubes
What are xylem tubes
The tubes in the plant that transfers water around
How do gases get in and out of the leaf
Through the tiny holes found on the bottom of the leaf called stomata.
Stomata are opened and closed by guard cells - they open during the day and close at night
Why are leaves green
Because they contain chlorophyll which absorbs sunlight
Why are leaves thin
To allow gases to diffuse in and out easily
Why do leaves have a large surface area
To absorb as much light as possible
Why do leaves have veins
These are xylem tubes they transport water and phloem tubes which transports glucose
Why is the underneath of a green leaf lighter than the top
Because the cells in the bottom of the leaf contain fewer chloroplasts which means less chlorophyll
Why does the top of the leaf feel waxier than the bottom which is dryer
Because the waxy layer reduces the amount of water evaporating out of the leaf - the sun heats up the top of the leaf which means more water will turn to escape
What are the two main leaf layers
Palisade layer
Spongy layer
What does the palisade layer do
Connects cells packed with chloroplasts - this is where most of the photosynthesis happens
What does the spongy layer do
Contains the air spaces allowing carbon dioxide to diffuse into the leaf and oxygen to diffuse out
What minerals do plant need
Nitrates
Phosphates
Potassium
Magnesium
Why do plant need nitrates
(Contain nitrogen) for healthy growth
Why do plants need phosphates
(Contains phosphorus) for healthy roots
Why do plants need potassium
For healthy leaves and flowers
Why do plants need magnesium
For making chlorophyll
Where do plants get minerals from
From the soil - the mineral are dissolved into the soil water and whosoever into the root hair cells
What is a mineral dificienty
When a plant doesn’t get enough minerals
What are the symptoms of a burnt rate deficiency
Plant will ok have poor growth and older leaves are yellowed
What are the symptoms of a magnesium deficiency
Plant leaves will turn yellow
What are the symptoms of a phosphorus deficiency
Plant will have poor root growth and younger leaves look purple
What are the symptoms of a potassium deficiency
Has yellow leaves with dead patches
Why are nitrates so important for plants
They are involved in making amino acids - they join together to form proteins. These proteins are needed for cell growth, to grow the leaves and shoots
Why is magnesium so important for a plant
Because the chlorophyll molecule contains magnesium- if the plant can’t get enough magnesium it can’t make as much chlorophyll as it needs
Why do farmers use fertilisers
Because when crops are harvested minerals are removed from the ground. So to prevent further crops suffering from a mineral deficiency farmers add chemicals to the soil to replace the missing minerals
How do cells transfer energy
Form organic molecules in the food you eat. To transfer the energy stored in food glucose reacts with oxygen in a chemical reaction called aerobic respiration
What is the word equation for aerobic respiration
Glucose + oxygen —> carbon dioxide + water (+energy)
Where does respiration happen
Inside tiny structures inside you cells called mitochondria
Muscles carry out a lot of respiration so they contain lots of mitochondria
How does glucose get into your cells
Glucose in a carb found in food- digestion breaks down food into small molecules releasing the glucose molecules. The molecules are absorbed by the wall in the small intestine into your blood stream and then carried around you body in the liquid part of you blood called PLASMA
How does oxygen get into cells
Oxygen fills the alveoli in your lungs when you breath in. The oxygen then diffuses into you bloodstream and is carried by red bleeding of cells in your body - they contain haemoglobin. When it reaches a cell requiring oxygen it diffuses in
How does carbon dioxide leave your body
You get rid of it when you exhale. It diffuses out of your cells and into blood plasma. The blood transports it to the lungs where is diffuses in to the air sacs and is then exhaled
What is anaerobic respiration
A type of respiration that does not use oxygen
When is anaerobic respiration used
When doing sprints or when the body needs energy quickly
What is the word equation for anaerobic respiration
Glucose —> lactic acid (+energy)
What does you body normally respire aerobically
Aerobic respiration transfers more energy per glucose molecule
The lactic acidosis produced from anaerobic respiration can cause painful cramps in you muscles
What other animals might anaerobic respiration take place in
When a fox chases a rabbit
What is fermentation
A chemical reaction used by microorganisms to convert glucose into ethanol, carbon dioxide and energy
What is the word equation for fermentation
Glucose —> ethanol + carbon dioxide (+energy)
What products are made using fermentation
Bread, beer and wine
How do you make bread
Bakers mix flour, water and yeast together. The yeast ferments the carbohydrates in the flour into ethanol and carbon dioxide - the gas trapped in the dough makes it rise.
When the dough is baked the ethanol evaporates
What is a food chain
A diagram that shows what an organism eats - it shows the transfer of energy between organisms
What are the features of a food chain
The first organism is the producer (grass)
The second organism is a herbivore (zebra)
The third organism is a carnivore (lion)
The arrows show the transfer of energy
What is prey
An animal that is eaten by another animal
What is a predator
An animal that eats other animals
What would happen if a food chain had more than four or five links
Too little energy would be transfers to organisms at the top of the chain
What happens as you go up a food train
Some of the energy is transferred to the surroundings this means that each level of the food chain has less energy transferred
What is a top predator
An animal no eaten by any other animals - it’s always the last link in the food chain
What is a food web
A set of linked food chains
What do food webs show us
The feeding relationships of organisms more realistically
What is interdependence
The way living organisms depend on each other to survive, grow and reproduce
What is a population
The number of animals or plants of the same species that live in the same area
What is bioaccumulation
The build up if toxic chemicals inside organisms in a food chain
What is an example of bioaccumulation
When there are toxins in a river, fish absorb these, the seal eats the fish which contains toxins, a shark eats the seal now it also contains toxins
What is an ecosystem
An ecosystem is the name given to the plants animals that are found in a particular location and area which they live in
What is a community
The plants and animals found in a particular area
These are the organisms that make up a community
What is a habitat
The place where an animal or plant lives
What is a niche
The particular place or role that an organism has in an ecosystem
What does co-exist mean
When plants abs animals in a community and a habitat live in the same place at the same time
