B4 quick questions

Question 1

what are the four main components of blood

Answer 1

white blood cell, redblood cell, plasma and platelets

Question 2

what is the function of platelets

Answer 2

form blood clots-prevent loss of blood and stop wounds becoming infected

Question 3

describe three adaptations of a red blood cell

Answer 3

• biconcave disc large sa to volume ratio for diffusion of oxygen
• contains haemoglobin which binds to oxygen
• no nucleus more space for oxygen

Question 4

how do white blood cells protect the body

Answer 4

• engulf pathogens

- produce antitoxins to neutralise toxins or antibodies

Question 5

name the substances transported in blood by plasma

Answer 5

hormones, proteins, urea, carbon dioxide and glucose

Question 6

why is the human circulatory system a double pump system

Answer 6

blood passes through the heart twice for every cycle around the body, deoxyginated blood is pumped from the right side of the heart to the lungs ant the oxyginated blood that returns is pumped from the left side of heart to body

Question 7

how does the structure of an artery relate to its function

Answer 7

carries blood away from heart-under high pressure, has a small and thick lumen, and elasticated walls that can stretch

Question 8

how does the structure of a vein relate to its function

Answer 8

carries blood back to heart at low pressure, doesnt need thick elasticated waalls but has valves to prevent blood flowing the wrong way

Question 9

how does the structure of a capllary relate too its function

Answer 9

carries blood to cells and tissues has a one cell thick wall to provide short diffusion distance

Question 10

list the structures air passes through when breathing in

Answer 10

mouth/nose, tranchea, bronchi, bronchioles, alveoli

Question 11

why is a leaf an organ

Answer 11

there are many tissues in a leaf that work together to perform photosynthesis

Question 12

how is the upper epidermis suited to its function

Answer 12

• singlelayer of transparent cells to aloow light through

- cells secrete a waxy substance that makes leaves waterproof

Question 13

how is the pallisade mesophyll adapted for its function

Answer 13

tightly packed cells with lots of chloroplasts for more photosynthesis

Question 14

how is the spongy mesophyll adapted for its function

Answer 14

air spaces to increase the sa allowing gas to diffuse quickly

Question 15

what is the function of the guard cells

Answer 15

control the opening and closing og the stomata

Question 16

what is the function of the xylem

Answer 16

transport water and mineral ions from the roots around the plant

Question 17

give three adaptations of the xylem

Answer 17

• made of dead cells
• no end wall between cells
• walls strenghtened by a chemical called lignin to withstand pressure of thewater

Question 18

function of phloem

Answer 18

transport disolved sugars from leaves to rest of the plant

Question 19

what is the purpose of translocation

Answer 19

transport dissolved sugars from the leaves to the rest of the plant

Question 20

define the term transpiration

Answer 20

movement of water from roots to rest of plant

Question 21

whatis purpose of transpiration

Answer 21

• provide water to keep cells turgid
• provide water for photosynthesis
• transport mineralions to leaes

Question 22

factors that affect the rate of transpiration

Answer 22

temp, light intensity, humidity and wind speed

Question 23

how does humidity have an effect on transpiration

Answer 23

higher temp increases rate of transpiration

Question 24

why does light intensity increase rate of transpiration

Answer 24

stomata open wider to let more carbon dioxide into leaf for photosynthesis

Question 25

what is function of the stomata

Answer 25

allow diffusion of gases into and out of the plant

Question 26

where are most stomata found

Answer 26

underside of leaves

Question 27

what is the advantage of the plant having a high number of stomata at this location

Answer 27

reduces amount of water loss through evaporation