Transport long questions

Question 1

Blood cells’ defences and blood clotting process

Answer 1

1. When there is a wound, platelets will gather at the injured blood vessel, form a coagulation and secrete thrombokinase enzyme.
2. The thrombokinase enzyme acts on the inactive prothrombin and changes it into active thrombin in the presence of calcium ions and vitamin K.
3. Thrombin catalysts the conversion of soluble fibrinogen into insoluble fibrin.
4. The fibrin forms a netting that traps the erythrocytes below it
5. In this way, the wound will close and bacteria are prevented from entering the body
6. If bacteria manage to enter the body through the wound, the blood circulatory system will react in 2 ways:

Phagocytosis
Phagocytes will surround the bacteria, swallow and destroy them

Production of antibody
Bacteria can also be destroyed by the antibodies that is secreted by lymphocytes

Question 2

The link btw high blood pressure and the accumulation of tissue fluid

Answer 2

1. High blood pressure at arterial end forces out more fluid from capillary
2. High blood pressure at the venous end of the capillary reduce the amount of lymph reabsorbed
3. The lymph system would not be able to drain all the excess tissue fluid rapidly enough

Question 3

Why tissue fluid accumulates more in ankles and feet

Answer 3

1. Gravity causes tissue fluid to accumulate in the ankles and feet
2. fewer lymph vessel in these areas

Question 4

why does a patient diagnosed with Elephantiasis has swollen legs

Answer 4

The patient has a blockage of lymphatic system by certain parasitic round worms
(Brugia sp. cause lymphatic filariasis)
(transmitted by mosquito bites)

The worm prevent the lymph from returning to the bloodstream

produce millions of larvae that circulate in the blood and cause affected area to become swollen

Question 5

Purpose of giving a small first dose of vaccination, followed by a larger booster dose later on

Answer 5

A small first dose is given to induce the formation of antibodies

Larger booster dose is given to increase the number of antibodies to an effective level to combat pathogens

Question 6

How bacteria are destroyed by phagocytes

Answer 6

1. Phagocyte is attracted by chemicals released by bacteria
2. extends pseudopodia towards it and engulf it by phagocytosis
3. Bacteria will be packaged into phagosome
4. The phagosome fuses with lysosomes to form phagolysosome
5. Lysosome releases lysozyme to digest the bacteria

Question 7

Why upper part of the plant become swollen and bigger than the area of lower part

Answer 7

1. phloem cut off
2. food supply from the upper part cannot be transported to the lower part
3. but are collected above upper part causing area to swell up

Question 8

Transpirational pull

Answer 8

1. Water on external surfaces of mesophyll cells evaporates
   saturating the air spaces in the mesophyll cell with water vapour
2. air in atmosphere less saturated
3. water vapour in air spaces evaporates and diffuses thru stomata
4. movement of air carries water vapour away from stomata
5. loss of water in mesophyll cell makes cell hypertonic to adjacent cell
6. water diffuses into cell via osmosis
   water continues to diffuse from neighbouring cells to adjacent cells
7. pulling force is created to pull water up the xylem vessels
   known as transpirational pull

Question 9

opening of stoma

Answer 9

1. daytime, light stimulates guard cell for photosynthesis
2. guard cell start synthesizing glucose
   generate energy required for active transport
3. guard cell accumulate potassium ions from adjacent cells thru active transport
4. guard cell become hypertonic
   water enter diffuses into guard cell via osmosis
5. guard cell swell up and become turgid

6.( cuz inner cell walls of guard cells thicker than outer cell walls)
guard cells bend outwards and stoma opens
(thinner wall stretches more than thicker wall)

Question 10

closing of stomata

Answer 10

1. nightime, no photosynthesis
2. potassium ions leave guard cell
   water leave guard cell via osmosis
3. guard cells become flaccid
   stoma closes

Question 11

adaptation of xylem vessels

Answer 11

1. the vessel are elongated cells arranged end to end
   this allows water to flow in a continuous column
2. the end walls of vessel have broken down to provide an uninterrupted flow of water up the plant
3. the side walls of xylem vessel are perforated by pits which allow water and mineral salts to pass sideways
4. the narrowness of lumen of xylem vessels increases the capillary force