b4 organising animals and plants Flashcards
What are the four main components of blood?
Red blood cells, white blood cells, platelets, and plasma.
What is the function of red blood cells?
Carry oxygen from the lungs to the body using haemoglobin.
What is the function of white blood cells?
Fight infections as part of the immune system.
What is the function of platelets?
Help blood clot to prevent bleeding.
What is the function of plasma?
A liquid that carries nutrients, hormones, and waste products.
What are the three types of blood vessels?
Arteries, veins, and capillaries.
What is the function of arteries?
Carry oxygenated blood away from the heart at high pressure.
What is the function of veins?
Carry deoxygenated blood back to the heart at low pressure.
What is the function of capillaries?
Allow exchange of substances (e.g., oxygen, glucose) between blood and tissues.
What is the function of the heart?
Pump blood around the body to deliver oxygen and nutrients.
What are the four chambers of the heart?
Right atrium, right ventricle, left atrium, and left ventricle.
What is the pathway of blood through the heart?
Body → Vena cava → Right atrium → Right ventricle → Pulmonary artery → Lungs → Pulmonary vein → Left atrium → Left ventricle → Aorta → Body.
Why is the left ventricle wall thicker than the right?
It pumps blood around the whole body, so it needs more muscle to generate higher pressure.
What are coronary arteries?
Blood vessels that supply the heart muscle with oxygen and nutrients.
What is the role of valves in the heart?
Prevent backflow of blood, ensuring it flows in one direction.
What are the main plant organs?
Roots, stems, leaves, and flowers.
What is the function of epidermal tissue in plants?
Covers the plant and protects it from water loss and pathogens.
What is the function of palisade mesophyll tissue?
Contains chloroplasts for photosynthesis.
What is the function of xylem tissue?
Transports water and minerals from roots to leaves.
What is the function of phloem tissue?
Transports sugars (e.g., glucose) from leaves to the rest of the plant.
What is meristem tissue?
Found at growing tips of roots and shoots; it allows plants to grow.
What is the function of root hair cells?
Increase surface area for absorption of water and minerals from the soil.
What is transpiration?
The loss of water vapour from the leaves through stomata.
What is the transpiration stream?
The movement of water from roots → xylem → leaves → atmosphere.
What factors increase the rate of transpiration?
High temperature, low humidity, high wind speed, and bright light.
What are stomata?
Tiny pores on the underside of leaves that allow gas exchange and water loss.
What is the role of guard cells?
Control the opening and closing of stomata to regulate transpiration.
How does water move through a plant?
Water moves up the xylem by cohesion (water molecules stick together) and adhesion (water sticks to xylem walls).
Why is transpiration important for plants?
It helps transport water and minerals, cools the plant, and maintains cell turgidity.
