B4 - Organising animals and plants Flashcards
What are the components of blood?
- Plasma (55%)
- Red blood cells (45%)
- White blood cells (
<1%) - Platelets (
<1%)
Name the features of a red blood cell
- they are biconcave discs
- no nucleus
- contain heamoglobin
- thin membrane
Why are red blood cells biconcave discs?
Increase surface area to absorb oxygen
Why do red blood cells have no nucleus?
To increase the volume for hemoglobin
Why do red blood cells have a thin membrane (wall)
To allow gases to easily diffuse through
What are protein markers called?
antigens
What are the two main types of white blood cell
lymphocytes - produce antibodies
phagocytes - engulf and digest pathogens
What does oxygen and hemoglobin form
Oxyhaemoglobin
What does plasma transport
- blood cells
- platelets
- dissolved foods
- carbon dioxide
- urea
- heat
Name the features of platelets
- smaller than red blood cells
- fragments of cells
- irregular shape
- no nucleus
What do platelets do
Help blood clot
What are the the three blood vessels
- artery
- vein
- capillary
What is the lumen of a blood vessel
the channel/cavity
empty space for blood
What are the features of an artery
- thick walls
- thick layer of muscle and elastic fibres
- small lumen
What are the features of a vein
- thin walls
- large lumen
- valves
What are the features of a capillary
- tiny vessel
- small lumen
- walls 1 cell thick
what type of circulatory system do humans have
double circulatory system
what are the purposes of all three blood vessels
arteries - carry blood away from the heart, thick elastic walls allow high pressure blood to flow through
veins - carry blood towards the heart, valves stop blood from flowing the wrong direction
capillaries - connect arteries and veins, substances diffuse out because of thin cell wall
why is a double circulatory system important in warm blooded animals?
it allows for efficiency. more areas of the body can recieve oxygenated blood quickly
what muscle is the heart made from
cardiac muscle
what are the properties of cardiac muscle
it is untiring and involuntary
what are the two sections of the double circulatory system
pulmonary circulation - heart to lungs and back
systemic circulation - heart to body cells and back
Where does heamoglobin have a high affinity for oxygen
in the lungs
what is a pulse
the rate of which the arteries expland and contract
how does blood travel through the heart
- blood enters the atrium
- the atria contracts and blood is forced into the ventricle, valves close to make sure blood does not flow back
- the ventricle contracts forcing blood out of the heart
what are 3 methods of combating CHD
Coronary Heart Disease
- stent - a metal mesh placed in the artery to open a blood vessel
- bypass surgery - rerouting blood through another blood vessel arounded the blocked one
- statins - a medication which lowers cholesterol in the blood which protects the inside of the coronary arteries
Why might someone need an artificial pacemaker
if they have an irregular heartbeat
Where is the pacemaker in the heart found
right atrium
How does oxygen travel to the alveoli
- air travels to the lungs through the trachea
- trachea divides into 2 tubes called the bronchi
- the bronchi branch out into bronchioles
- bronchioles attatch to alveoli
bronchus (plural ‘bronchi’); bronchiole (plural ‘bronchioles’)
what is the concentration gradient
the difference in the concentration of a substance between 2 areas
what can increase the rate of diffusion in the alveoli (3)
- The concentration gradient of gases
- The temperature
- The surface area
What are organs made from
organs are made from tissues which are groups of similar cells that preform a similar function together
What are the 4 major organs in plants
- reproductive structures
- leaves
- stems
- roots
name 4 main components of a plant leaf
- epidermal tissue
- spongy mesophyll
- palisade mesophyll
- stomata
what is the spongy mesophyll
the spongy mesophyll has many air spaces and a large surface area which makes the diffusion of gases easier, they also contain some chloroplasts
what is the epidermal tissue
the epidermal tissue and its waxy cuticle covers the outer surface of the leaf to ensure there in no water loss or damage to the leaf
what are the stomata
they are gaps found in the lower epidermis that facilitate diffusion of gases in and out of leaves
what is the purpose of guard cells
to open and close the stomata
e.g. in high temperature the stomata will close to prevent water loss
what is the palisade mesophyll
located below the upper epidermis. exposed to sunlight so the cells contain chloroplasts to maximise the energy from photosynthesis.
what are the 2 transport systems in plants
xylem and phloem
what does phloem transport, what is the process called
transport sugars made by photosynthesis from the leaves to the rest of the plant
this movement is called translocation
what does xylem transport
transports water and mineral ions from the roots to the rest of the plant
name if these cells are dead or alive:
1. xylem
2. phloem
- xylem - dead cells
- phloem - alive cells
what is the direction of transport for phloem and xylem
phloem - upwards and downwards
xylem - upwards
how are phloem and xylem arranged
in vascular bundles
what is transpiration
water vapour diffusing out of a leaf through the stomata
what is the transpiration stream
the constant movement of water from the roots to the leaves
what is osmosis
the movement of molecules through a membrane dependant on the concentration gradient
when do the stomata open
guard cells open the stomata when they become turgid
turgid - swollen with water
when do the stomata close
guard cells close the stomata when they become flaccid
flaccid - lacking turgidity, loose
what is the word equation for photosynthesis
Carbon dioxide + Water → Glucose + Oxygen
what is the chemical equation for photosynthesis
6CO2 + 6H2O → C6H12O6 + 6O2
4 factors that affect the rate of transpiration
- temperature
- air movement
- humidity
- light intensity
why does temperature affect the rate of transpiration
water has more energy so it diffuses faster
why does humidity and air movement affect the rate of transpiration
the concentration gradient of water vapour in air to the water in the leaf affects the rate of transpiration, water will be pushed out if the air has a low concentration of water vapour. air movement can carry humid air away leaving dry air
why does light intensity affect the rate of transpiration
more photosynthesis can take place which means faster transpiration
what is adhesion
a molecules ability to stick to different molecules
what is cohesion
a molecules ability to stick to another molecule of the same type
what are the features of phloem tubes
- arranged in phloem cells put from end to end
- between cells there are pores that allow cell sap to pass
- alive cells
what are the features of xylem tubes
- dead cells joined end to end
- lignin to strengthen structure
- no pores, one continuous tube
