B4 - Organising Animals And Plants Flashcards
Components of the blood and functions?
- Red blood cells - carry oxygen
- White blood cells - part of the bodies defence system, some make antibodies, and antitoxins, and some digest bacteria and viruses
- Platelets - small fragments of cells. Help blood clot as a wound.
- Plasma - transports all blood cells and some others around body
How are red blood cells adapted?
- increased SA:V ratio (biconcave discs)
- packed with haemoglobin that binds to oxygen
- no nucleus to make space for haemoglobin
How does the blood clot?
Enzymes help convert fibrinogen to fibrin, which produces a network of protein fibres that captures blood cells and forms a clot to stop excessive bleeding. Dries and gardens to form a scab. Stops bacteria entering body
What does the plasma carry? And where does it take them?
- Waste CO2 produces by the cells - lungs
- Urea formed in liver from break down of proteins - kidneys
- Small soluble products of digestion - from small intestine to cells
3 main types of blood vessels?
Arteries, vessels, capillaries
What direction to arteries carry blood?
Away from heart and to organs. (Oxygenated)
What direction to vessels carry blood?
Away from organs to the heart (deoxygenated)
Capillaries allow…
The diffusion of substances such as oxygen and glucose into the cells, and substances such as CO2 to diffuse into blood.
D. Double circulatory system?
The circulation of blood from the heart to the lungs is separate from the circulation of blood from the heart to rest of body
Function of stents?
Keep narrowed or blocked arteries open
Function of statins?
Reduce cholesterol levels in blood, reducing risk of coronary heart disease.
What is a natural pacemaker?
A group of cells in the right atrium that form a natural pacemaker
Adaptions of alveoli?
- rich supply of capillaries which maintain a steep conc gradient in both directions
- very large surface area
Examples of plant organ systems?
Roots, stem and leaves form a organ system
D. Translocation?
The movement of dissolved sugars from leaves to the plant.
Why is transport in plants so important? (4)
- all cells need glucose for respiration
- minerals are needed for production of proteins -“and molecules within a cell
- need water for photosynthesis
- needs water to remain turgid
D. Transpiration?
The loss of water vapour from the stomata
Through what is water lost in plants? Why?
The stomata as they open to allow CO2 to enter
What controls water loss and gas exchange in a plant?
The stomata and guard cels
The size of the opening of the stomata is controlled by…..
Guard cells
How does the transpiration stream work?
As water evaporates, more is pulled up through the xylem to replace it. It’s driven by evaporation.
Factors that increase the rate of photosynthesis?
Humidity, CO2 conc, temperature, light intensity and air flow
Transpiration is more rapid in what conditions?
Dry/wind/hot
What does the pulmonary artery do?
(Right v.) takes for the Bates blood to the lungs.
What does the aorta do?
(Left v.) takes oxygenated blood around the body.
What does the pulmonary vein do?
Brings oxygenated blood from the lungs.
What does the Vena cava do?
Brings deoxygenated blood into the heart.
Adaptations of villi?
- Increased surface area due to folding = max absorption
- Single later of thin cells = small diffusion distance
- Rich blood supply (capillaries) to distribute dissolved food molecules.
Adaptations of alveoli? (4)
- Walls are 1 cell thick = short diffusion distance/exchange surface very thin
- Rich blood supply = take oxygen away and bring C02 which maintains max concentration gradient.
- Folded = greater surface area for gas exchange
- Ventilated = removed waste C02 and replenish oxygen levels. Maintain max conc gradient between alveoli and blood.
