biology -blood , blood vessels and the heart b2

Question 1

artery (blood vessel)

Answer 1

-carries blood AWAY from heart
-insides are narrow lumins to maintain high pressure
-thick elastic and muscular fibers to withstand high pressure

Question 2

capillary (blood vessel)

Answer 2

-one cell thick -short distance for diffusion
-carbon dioxide diffuses in
-oxygen diffuses out
-narrow tube only allows one red blood cell

Question 3

veins ( blood vessels)

Answer 3

-thin elastic and muscular fibers due to low pressure -wide lumin to increase blood flow due to narrow pressure
-valves preventing blood flowing in the wrong direction
-valves can close
-veins take blood BACK to the heart

Question 4

red blood cells

Answer 4

-no nucleus
-contains haemoglobin which carries the oxygen
-bioconcaved shape to increase surface area so diffusion can happen faster

Question 5

white blood cells

Answer 5

-fight infection
-lymphocytes- produce antibodies and antioxidants
-phagocyte- surrounds and engulfs pathogens

Question 6

platelets

Answer 6

-cause blood to clot
-small fragments of cells
-no nucleus

Question 7

plasma

Answer 7

-the liquid part of blood
-carries both useful and waste substances
-yellow/ straw colour

Question 8

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