B2.2 Flashcards
What is respiration
An enzyme catalysed reaction that releases the energy needed for us to use and live
What happens in aerobic respiration
The glucose in the body reacts with oxygen to form carbon dioxide plus water and energy
Glucose + oxygen —> carbon dioxide + water + energy
What does blood need to carry
Glucose and oxygen to the cells and carbon dioxide away from them
What happens in diffusion
When particles of a substance spread out, moving from an area of high concentration to an area of low concentration. They diffusé down a concentration gradient
What are alveoli and purpose. What is gas exchange
They are tiny sacs that make up the lungs and are surrounded by capillaries. Oxygen comes into the lungs and diffuses through the alveoli and into the blood. As oxygen enters the blood, carbon dioxide leaves it, this is gas exchange
Why does exercising increase heart rate
When you exercise, muscle cells are using more energy as muscles are moving more. This means they need more oxygen and need more carbon dioxide to be removed. To do this faster, you breath faster and the heart beats faster to get the blood with oxygen to the muscles fast and to remove the carbon dioxide fast
What is stroke volume
The volume of blood pumped per beat
What is cardiac output
The volume of blood circulated in the body in a given time, worked out by
Cardiac output = stroke volume x heart rate
What happens in anaerobic respiration
Occurs when not enough oxygen
Glucose —> lactic acid + less energy
What is epoc
Excess post exercise oxygen consumption. It’s when the body needs to keep breathing heavily after exercise to get oxygen to break down the lactic acid build up from anaerobic respiration
What is the recovery time
The time taken for pulse to return to resting levels after exercise
What is photosynthesis
The process plants use to make glucose from water and carbon dioxide for energy, using the sun
Carbon dioxide + water —> glucose + oxygen
How does photosynthesis work
Photosynthesis is a series of complex catalysed reactions. It occurs in chloroplasts in the leafs. Light enters the leaf and into the chloroplasts. Chlorophyll in the chloroplasts convert light energy into the chemical energy stored in glucose
How is starch detected
Iodine solution turns leafs dark blue if starch. Only places with chlorophyll in the leaf will go dark
Adaptations of leafs
Lots of chlorophyll for photosynthesis. Large broad thin shape for large surface area so absorb as much light as possible. Underneath are stomata, stoma, these absorb carbon dioxide and release oxygen, doing both through diffusion. Lots of air sacs to give the cells a large surface area to volume ration for efficient gas exchange
How can plant growth be maximised
Providing it with optimum conditions for photosynthesis so more glucose can be made which is used for making proteins for growth and respiration
What are the four conditions for photosynthesis
Good levels of sun light, good temperature, good amount of water and good amount of carbon dioxide
What is a limiting factor
The factor in a reaction that is in lowest supply so not matter how much of the other factors is added, it will remain slow until the limiting factor is increased
What are roots for
Anchoring the plant for support, absorbing mineral salts such as nitrates and absorbing water
What are root hair cells
Long thin extensions on the surface of roots that provide a large surface area to allow substances to enter the root
What happens in osmosis
Water in the ground diffuses into the root hair cells though a semi permeable membrane so only water can get through and not other substances.
What is active transport
The movement of substances such as nitrates and other mineral ions dissolved in soil water into the plant even when concentration is greater in the plant than in the soil. Movement of substances against the concentration gradient is active transport and energy is needed for this
How are substances such as water and the dissolved mineral ions transported in the plant from the roots.
Specialised cells called xylem grow in elongated shaped. These then die to form hollow tubes in the plant which are used to transport water and mineral ions through it and to support the plant
How is sugar transported in leafs
It is first made as glucose in photosynthesis but then converted into sucrose and transported around to other parts of the plant by strands of living tissue Calle phloem
What is the process called and how is water moved up a plant
The process is called transpiration. Water that evaporates from cells in the leafs move and diffuse out of the stomata. This means there is less water at the leafs, there is now a conc gradient. This pulls up salt mineral rich water from in the roots through the xylem. Factors that will increase water evaporation in plants will increase transpiration
How can too much water kill you
Blood becomes very dilute and causes the brain to swell due to osmosis, this can then cause seizures and even death.
How can salt water kill you
Salt in blood causes water to leave cells and make them shrivel and die, the opposite of too much normal water
Why do plants become droopy from lack of water
When a plant cell has lots of water surrounding it, it will absorb it all through osmosis. This causes the cell to swell and become rigid, making the plant rigid and upright. When it uses all the water and there isn’t any around it, the cells will shrivel and collapse almost making them not as rigid and causing the plant to droop.
Why do scientists study the biodiversity of an ecosystem or habitat
To monitor changes in population size of organisms and distribution and to test hypotheses about which organisms live where
What is sampling and how is it done
It is studying the biodiversity of a small random area that is then used to represent the whole larger area. Quadrants, square frames of a known size are usually randomly thrown and the area within is what the scientists study.
How are small invertebrates captured for studying, insects
A pooter is used. The inlet tube is placed near the specimen and the mouth piece is sharply sucked on to suck the insect into the container through the inlet tube
How are nets used to capture specimens
A sweep net can be swept through long grass to catch any organisms living on the grass, similarly, a pond net can be used to sample aquatic habitats
He does a pitfall trap work and what is it for
Used to catch small insects such as spiders and beetles. It consists of a hole in the ground with a slightly raised lid. This means when an insect falls into it, it becomes trapped. It can be left overnight for collection
How is population estimated in a habitat
Quadrats are thrown and the population of a species is counted, the average number of species per quadrat is used to estimate the total population
What is systematic sampling
Sampling done but not in a random way, such as placing quadrats along a line at regular intervals
