b4 - organising animals and plants

do animals with large / small surface area to volume ratio have specialised transport systems

small

the blood is on what level of organisation

tissue

what is blood based on?

plasma

what does plasma carry apart from blood components?

waste carbon dioxide to lungs, urea to kidneys and products of digestion to individual cells

how many litres of blood does the average person have?

4.7 - 5 litres

what colour is plasma?

yellow

red blood cells adaptations

• bi concave discs
  - packed with haemoglobin
  - no nucleus

white blood cells are larger / smaller than red blood cells

larger

two ways white blood cells deal with pathogens

• produce anti toxins against the toxins made by pathogens
  - engulf and digest pathogens

what are platelets?

• small fragments of cells
  - no nucleus
  - help blood clotting

what is blood clotting chemically speaking

converting fibrinogen to fibrin which makes a network of proteins to catch RBCs and platelets so you dont bleed to death

blood clotting benefits

stops pathogens from entering the body

blood vessel types

• arteries
  - veins
  - capillaries

in veins how is blood pumped back to heart?

by skeletal muscles

double circulatory meaning

• one system takes deoxygenated blood to the lungs
  - another system takes it around the body and back to the heart

what is a double circulatory essential in

warm blooded active animals like humans

what do valves do

prevent backflow of blood

how is the heart supplied with oxygen

cornoary arteries

how is cornoary heart disease treated

with a stent

what are stents for?

opening up blocked/narrowed arteries

what is bypass surgery

replacing narrow or blocked cornonary arteries with bits of veins from other parts of the body

who are statins for 

for someone at risk of cardiovascular disease

what do statins do

reduce blood cholesterol levels and this slows down the rate at which fatty material is deposited in the coronary arteries

where is the pacemaker of the heart situated

right atrium

what can mechanical heart valves be made of

titanium or polymers

how long do biological valves work for

12-15 years

biological valve donors

cattle, pigs or humans

how much do artifical pacemakers weigh?

20-50g

what is needed for a gas exchange system to work efficiently

a steep concentration gradient

how do humans maintain a steep concentration gradient

by changing the composition of the air in the lings, they maintain a steep concentration gradient

why do humans need a steep concentration gradient

for oxygen diffusing into the blood and carbon dioxide diffusing out of the blood

where are your lungs found

thorax

what are lungs protected by

ribcage

how are the lungs separated from the digestive organs

by the diaphragm

what is the diaphragm

a strong sheet of muscle

how does ventilating the lungs work

by contraction and relaxation of the intercostal muscles between ribs and the diaphragm changing the pressure inside the thorax so air is forced in or out of the lungs as a result of the differences in pressure

what are the adaptations of the alveoli

• large surface area
  - great blood supply from capillaries
  - short diffusion distance

why in the alveoli having rich blood supply leads to more efficient gas exchange

a steeper concentration gradient

in plants what do epidermal tissues usually secrete

a waxy substance to waterproof the surface of the leaf

what does palisade mesophyll contatin a lot of

chloroplasts

what do spongy mesophyll contain

• chloroplasts
  - big air spaces & large surface area

why does the spongy mesophyll having large air spaces and large surface area help the overall efficiency of the plant

to make diffusion of gases easier

what are the transport systems in plants

xylem and phloem

what does the xylem carry

water and dissolved mineral ions from the roots up to the leaves

what do the phloem carry

dissolved food from the leaves around the plant

what is the meristem tissue made up of 

rapidly dividing plant cells that grow and differentiate into all the other cell types needed

plant organs

• leaves
  - stems
  - roots
  - flower

what is the main photosynthesis product

glucose

what is the glucose from photosynthesis used for

respiration

what is phloem moving the nutrients called 

translocation

what is the xylem moving water and mineral ions called

transpiration

how do greenflies and other aphids attack plants

sticking their sharp mouthparts into phloem and feed off sugary fluid

mature xylem cells are what

dead

in trees the xylem is what

the bulk of the organism

why do plants need water 

to hold themselves upright and for photosynthesis

what are mineral ions needed for

production of proteins and other molecules within the cells

what is the size of the stomata controlled by

the guard cells

loss of water vapour is what

transpiration

why is it important stomata can close

to limit loss of water vapour

anything that increases the rate of photosynthesis increases the rate of {{c1::transpiration}}

factors that affect transpiration

• temperature
  - humidity
  - windiness
  - light intensity
  - no. of stomata 

water vapour diffuses more rapidly into {{c1::dry}} air than {{c2::humid}} air

why does water vapour more easily diffuse into dry air

as the concentration gradient would be steeper

how to control water loss in a plant

• waxy cuticle
  - wilting
  - stomata close

why does wilting control the rate of transpiration

as the surface area dramatically decreases for water loss by evaporation

what equipment is used to measure rate of transpiration

potometer

what conditions is transpiration more rapid in

hot dry windy or bright conditions

did u get everything (use mwb)

yes

did u get everything (use mwb)

yes

did u get everything (use mwb)

yes

did u get everything

yes

did u get everything (do on mwb)

yes

did u get everything (do on mwb)

yes

did you get everything (do on mwb)

yes