Organisation - Tissues, Organs And Organ Systems Flashcards
what is the process in which cells become specialized
differentiation
when does differentiation occur
development of organism
what is a tissue
a group of similar cells that work togerther to carry out a particular function
what does the liver produce
bile
what is the thorax
top part of body seperTED FROM LOWER PART by the diaphram. the lungs are in the thorax and are protected by the rib cage and surrounded by the pleural membranes
what is the path of the air into your lungs
trachea which splits into 2 tubes called bronchi which split into bronchioles. the bronchioles end at small bags called alveoli
why does gas exchange take place
diffusion
what is breathing rate calculated in
breaths per minuet
what is the function of the circulatory system
food and oxygen delivery
carrys waste products like co2 and urea
explain the double circulatory system
fist circuit: right ventricle pumps deoxygenated blood to the lungs to take in oxygen. the blood then returns to the heart
second circuit: left ventricle pumpps oxygenated blood to organs, it gives up its oxygen and the deoxygenated blood returns to the heart
what re the names of the arteries on the left and right side of the heart
right: pulmonary artery
left: aorta
what are the names of the veins on the left and right side of the heart
right: vena cava
left: pulmonary vein
how does the musles in the heart get its oxygen
coronary arteries branch of aorta and surround the heart
how is blood pumped into the ventricles
atria contract
how is your heartrate controlled
group of cells in right atrium wall that act as a pacemaker by producing small electrical impulses which spread to the surrounding muscles, causing them to contract
what is an artificial pacemaker
little device thats implanted uundwr the skin and has a wire going to the heart. produces an elecrical current
what are arteries
blood vessels carry blood away from the heart high pressure walls are strong and elastic thick layers of muscle
what is the hole down the middle of a blood vessel called
lumen
what are capillaries
tiny permeable walls once cell thick narrow large surface area to olume ratio
what are veins
lower pressure
bigger lumen
valves
what is rate of blood flow measured in
ml/min
what is blood
a tissue with the function to transport substances around the body
what is blood made up of
red blood cells, white blood cells, platelets which are all suspended in a liquid called plasma
adaptations OF RED BLOOD CELLS
biconcave shape to give large surface area
haemoglobin which is a red pigment that carriers oxygen
dont have a nucleus
what is the product when oxygen and haemoglobin combines
oxyhaemoglobin
what are 3 things white blood cells can do
engulf
produce antibodies
produce antitoxins
what do platelets do
fragments of cells that have no nucleus that help the blood to clot at a wound to stop you losing too much blood and stops microorganisms from getting in
what is epidermal tissue and palisade mesophyll tissue
covers the whole plant and covered with a waxy cuticle to stop water loss
where most photosynthesis takes place so lots of chloroplasts and near top of leaf
what is the spongy mesophyll tissue
has big air spaces to allow gases to diffuse
what is an adaptation of the upper epidermis
transparent so light can pass through
what is the meristem tissue
found at growing tips of shoots and roots and is able to change into lots of different types of plant cells, allowing the pant to grow
what is the function of stomata
let co2 diffuse directly into the leaf and controlled by guard cells.
what are phloem tubes, how do they work and what do they do
columns of elongated living cells with pores in the end walls to allow cell sap to flow through
phloem tubes transport food from the leaves to the rest of the plant for immediate use or for storage
the process goes in both directions and is called translocation
what are xylem tubes and what do they do
dead cells joined end to end with no end walls between them. strengthened with a material called lignin
carry water and mineral ions up the plant. this is called the transpiration stream
what is the transpiration stream
loss of water from a plant
what is the journey of transpiration
water inside leaf evaporates and diffuse through the stomata
this creates slight shortage of water in leaf so more water is draw up from the rest of the plant through xylem vessels
this in turn means more water is drawn up from the roots
how does light intensity effect the rate of transpiration
increases rate. stomata close as its gets darker as photosynthesis cant happen in the dark. When stomata are closed, little water can escape.
how does temperature effect the rate of transpiration
higher temperature increases rate as water particles have more energy to evaporate and diffuse out of stomata
how does air flow affect the rate of photosynthesis
increased air flow means an increased rate of transpiration. if there is bad air flow the water vapour that surrounds a leaf doesn’t go away so their is a high concentration of water particles outside the leaf which decreases diffusion.
how does humidity affect the rate of transpiration
the less humid the faster the rate because it creates a larger concentration gradient for diffusion
how do you investigate the rate of transpiration
stick plant poking out boiling tube with water attached through a capillary tube into a beaker. measure how far the air bubbles moves through the capillary tube per unit of time. change variables such as light intensity and air flow and
how do guard cells work to open and close the stomata
two guard cells surround each stomata. when plant has lots of water the guard cells goes turgid into a kidney shape so the stomata is open for gaseous exchange needed for photosynthesis. when plant is short of water, guard cell goes flaccid and stomata shuts.
adaptations of guard cells
thin outer walls and thick inner walls
sensitive to light so close at night
more on underside of leaf because its shaded so less water will be lost
investigating stomata and guard cells
epidermal tissue on slide w drop of water. estimate total number of stomata under microscope using a sample And calculating a mean. compare distribution on different areas of the leaf.
