B4 organising animals and plants Flashcards
how does the heart pump blood around the body
a double circulatory system
what are the 4 chambers in the heart
right and left atrium
right and left ventricle
what are the function of the left and right atria
they receive blood from veins
what are the function of the left and right ventricles
pump blood out and into the arteries
what is the function of the right ventricle
The right ventricle pumps blood to the
lungs where gas exchange takes place.
what is the function of the left ventricle
The left ventricle pumps
blood around the rest of the body
how are alveoli adapted to be very efficient at exchanging oxygen and carbon dioxide
the have a large moist surface area
they have a rich blood supply
they are very close to the capillaries so the distance for gas to diffuse is very small
what is the function of the pulmonary artery
heart send blood back to the lungs
what is the function of the pulmonary vein
blood is taken back to the heart
what is the function of the aorta
carries oxygenated blood away from heart and into the rest of the body
what is the role of the vena cava
to transport deoxygenated blood to the right side of the heart for oxygenation
what is gaseous exchange
air obtained by breathing reaches the lungs through the trachea and this splits into 2 tubes called the bronchi then the bronchi divide to form bronchioles which are divided like branches at the end of the bronchioles there are alveoli (tiny air sacs) this is where gas exchange takes place
where is the pacemaker found
the right atrium
what is a pace maker
The natural resting heart rate is controlled by a group of cells
located in the right atrium that act as a pacemaker
what is an artificial pace maker
an electrical device which corrects irregularities in the heart
name the 3 different types of blood vessel
artery veins and capillaries
describe the artery
take blood from heart to organs
thick walls made of muscle due to heavy blood flow
describe the vein
take blood from organs to your heart
thinner walls and valves to prevent backflow
describe the capillaries
allow substances needed by cells to pass out of the blood
allow substances produced by cells to pass into blood
narrow thin walled blood vessels
describe the blood
Blood is a tissue consisting of plasma, in which the red blood cells, white blood cells and platelets are suspended.
what is plasma
plasma transports various chemical substances around the body such as the products of digestion, hormones and antibodies, urea and carbon dioxide
what are red blood cells
contain haemoglobin which binds oxygen to transport it from the lungs to the tissues and the cells which need it for respiration
what are the properties of red blood cells
do not contain a nucleus so there is more room for hemoglobin
very small to fit through capillaries
shaped like biconcave discs which give a large surface area si oxygen can diffuse quickly across them
what are the functions of white blood cells
help protect body against infection
they can change shape so they can squeeze out of the blood vessels into tissue or surround and engulf microorganisms
what are platelets
they are fragments of cells which collect at wounds and trigger blood clotting
what is the function of the epidermis
covers the outer surfaces of the plant for protection
what is the function of the palisade mesophyll
the main site of photosynthesis in the leaf
what is the function of the spongy mesophyll
air spaces between the cells allow gases to diffuse in the leaf
what is the function of the xylem vessels
transports water and minerals through the plant from roots to leaves also supports the plant
what is the function of the phloem vessels
transports dissolved food materials through the plant
where is meristem tissue found
found mainly in the tips of the roots and shoots where it can be produce new cells for growth
what is translocation
the movement of food through phloem tissue where the phloem tissue transports dissolves sugars from the leaves to the rest of the plants
what are the stomata
tiny holes found in the underside of leaves. They control water loss and gas exchange by opening and closing. They allow water vapour and oxygen out of the leaf and carbon dioxide into the leaf.
what is transpiration
the movement of water through the xylem tissue from the roots of the plant to the leaves where the stomata open and the water is evaporated
how does temperature affect transpiration
an increase in temperature will increase the rate of transpiration as more energy is transferred to the water allowing it to evaporate
how does air flow affect transpiration
faster air flow will increase the rate as it will blow away water vapour allowing more to evaporate
how does light intensity affect transpiration
increase the rate as the stomata will open and more photosynthesis takes place
how does humidity affect transpiration
an increase in humidity will decrease the rate because the air contains more water vapour so the concentration gradient for diffusion is lower
what is gas exchange
the delivery of oxygen from the lungs to the bloodstream, and the elimination of carbon dioxide from the bloodstream to the lungs and out of the body
