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.