2 structure and functions in living organisms H (transport in humans)

Question 1

composition of blood?

Answer 1

• red blood cells
• white blood cells
• platelets
• plasma

Question 2

what does plasma do?

Answer 2

transports

Question 3

plasma transports…

Answer 3

carbon dioxide, digested food, urea, hormones, heat energy

Question 4

how do the adaptations of red blood cells make them suitable for their function?

Answer 4

SHAPE - they are biconcave, which means they have high surface area for more haemoglobin to bind with oxygen (absorb)
LACK OF NUCLEUS - more space to store oxygen
PRESENCE OF HAEMOGLOBIN - it binds four oxygen molecules, allowing more to be transported around the body

Question 5

how does the heart function?

Answer 5

deoxygenated blood enters through the vena cava (from the body) and out through the pulmonary artery (to the lungs).
oxygenated blood enters through the pulmonary vein (from the lungs) and out through the aorta (to the body).

Question 6

how does the heart rate change during exercise?

Answer 6

• muscles use more oxygen as they move more
• more demand for oxygen
• heart pumps faster to transport more oxygen around the body

Question 7

how does heart rate change under the influence of adrenaline?

Answer 7

• more adrenaline means the heart rate increases
• this is due to higher demand of oxygen for respiration

Question 8

what factors increase the risk of coronary heart disease?

Answer 8

• poor diet (lots of saturated fats)
• smoking

Question 9

structure of a phagocyte:

Answer 9

• flexible
• lobed nucleus
• cytoplasm with granules
• cell membrane

Question 10

structure of a lymphocyte:

Answer 10

• large nucleus
• lots of DNA
• lots of proteins
• makes antibodies which are proteins
• little cytoplasm

Question 11

what is phagocytosis?

Answer 11

engulfing a pathogen

Question 12

how do phagocytes engulf pathogens?

Answer 12

• engulf pathogen into vesicle
• once pathogen is engulfed, it secretes enzymes called lysosomes onto the pathogen
• the enzymes break down the pathogen and the pathogen becomes destroyed

Question 13

how do lymphocytes destroy pathogens?

Answer 13

• produce antibodies
• these antibodies bind with the anti-gens on the pathogen
• then destroy the pathogen

Question 14

are lymphocytes or phagocytes specific?

Answer 14

lymphocytes

Question 15

P2 role of platelets:

Answer 15

• clot blood
• prevents blood loss and the entry of micro-organisms

Question 16

P2 what are vaccines?

Answer 16

• the manufacturing of memory cells
• they enable future antibody production to the pathogen to occur sooner, faster and in a larger quantity

Question 17

P2 how do vaccines work?

Answer 17

1. a small amount of dead or inactive pathogen is put into a sterile liquid
2. it is injected into a person
3. a sample of the pathogen is weakened or killed
4. the person’s white blood cells make antibodies against the pathogen, the pathogen is kill do and memory cells are made
5. if the pathogen enters the body in the future, the memory cells recognise the pathogen
6. more antibodies are produced and much faster
7. the faster response protects the person getting ill from disease