B4.1 The Blood

Question 1

Blood plasma

Answer 1

Olasma carries red blood cells, white blod cells and platelets suspended in it. It also carries many dissolved substances around your body. Your plasma is a yellow liquid and trsmports all blood cells and other substnaces in your body.

Question 2

Red blood cells

Answer 2

Blood cells pick up oxygen from the air in your lungs and carry it to ghe cells where it is needed. Red blood cells have adpatations that make jobs very efficient such as being biconcave discs which gives them an increased surface area to volume ratio for diffusion. They are picked with red pigment called haemoglobin that binds to oxygen. No nucleus making more space for haemoglobin

Question 3

White blood cells

Answer 3

White blood cells are bigger than red blood cells and there are fewer of them. No nucleus and form part of body’s defence system against harmful microorganisms. Some form antibodies against microorganisms and some form antitoxins against poisons made by microorganisms.

Question 4

Platelets

Answer 4

Platelets are small fragments of cells. No nucleus. They are important in helping blood to clot at the site of a wound. Blood clotting is a series of enzyme controlled reactions that result in converting fibrinogen into fibrin. Produces network of protein fubres that capture lots of red blood cells and platelets to form a jelly-like clot. Clot dries and hardens to form scab. Prevents bacteria into your body.