Unit 2 - Multicellular Organisms Flashcards
what are 3 parts of the nervous system?
Brain, spinal cord and peripheral nerves
how do you calculate surface area ?
Area = length x breadth (cm^2)
how do you calculate volume?
volume = length x breadth x height (cm^3)
how do plants take up water from the soil?
plants take up water from the soil by osmosis. Water absorption is largely carried out by the younger part of the roots which have tiny extensions called root hairs. These act to increase the surface area through which water can enter the plant
what transport tissue make up bundles called veins or vascular bundles?
xylem along with other transport tissue (phloem) make up bundles called veins or vascular bundles
where are the vascular bundles located in the roots?
in the roots vascular bundles are located in the centre
where are vascular bundles located in the stem?
i’m the stem ,vascular bundles are arranged towards outside to provide support
what does the xylem consist of?
xylem consist of long cells joined end to end to form tubes. The ends of the cells in the xylem vessels have broken down to allow free movement of water
what 2 things can happen to water when it enters a leaf?
it can be used for photosynthesis
it can be lost through pores by evaporation
within a leaf where does photosynthesis mostly occur?
photosynthesis occurs mostly in the palisade and spongy mesophyll cells within a leaf
what are stomatas?
stomatas are small pores found on leaf surfaces. They allow gasses to diffuse in and out of the leaf, but water can also be lost through them
what do plants need for respiration and photosynthesis?
plants need oxygen for respiration and carbon dioxide for photosynthesis. These gasses enter the plant thought the stomata
sugars produced in the leaves by photosynthesis need to be transported to other regions of the plant where they are : ?
sorted as starch
used to provide energy during respiration
converted into cellulose
what’s the name of the tissue that movement of sugars take place in?
movement of sugars take place in tissue called phloem
what is the circulatory system made up of?
the circulatory system is made up of the blood vessels and the heart which pumps the blood
in mammals what is transported through the blood?
in mammals nutrients, oxygen and carbon dioxide are transported in the blood.
can respiration take place without diffusion?
no without diffusion respiration cannot take place and cells die
what happens every time the heart beats?
every time the heart beats it forces blood into the arteries. As the blood surges along it stretches their walls
name 3 blood vessels
artery , capillary and vein
what is the function of an artery?
carries blood away from the heart
what is the function of a capillary?
exchange of materials with tissue
what is the function of a vein?
carries blood back into the heart
does a artery have valves?
no
does the capillary have valves?
no
do veins have valves?
yes
do arteries have thick or thin walls?
arteries have thick muscular walls and a narrow lumen (channel) because they carry blood under high pressure
are capillaries thick or thin?
capillaries are thin, narrow and have a large surface area.Forming networks are organs and tissue. They allow the exchange of materials
where does oxygen and food diffuse from?
oxygen and food diffuse from the blood into the body cells where they are used in respiration to provide energy.
and carbon dioxide which is produced diffuses from the cells into the capillaries
what are the 3 different types of blood cells?
red blood cell, white blood cell and platelet
what is haemoglobin involved in the transport of?
haemoglobin is involved in the transport of oxygen. It binds with oxygen to form oxyhaemoglobin
haemoglobin+oxygen ➡️ oxyhaemoglobin
what are special features of red blood cells?
they are biconcave discs, this increases the surface area allowing them to pick up more oxygen. They are small and flexible so they can fit through narrow blood vessels
what do lungs allow the body to do?
the lungs are organs which allow the body to take in oxygen and give out carbon dioxide
where are the lungs and the heart found?
the lungs and the heart are found in the thorax - this is a sealed unit formed by the chest wall and a layer of muscle called the diaphragm
what is the function of the trachea?
hallow tube that connects the mouth and nose to the bronchi supported by rings of cartilage which holds the airway open
what is the the bronchi?
two tubes that connect the trachea to the bronchioles
what’s the the bronchioles?
narrow tubes that spread across the lungs
what’s the function of the alveoli (air sacks)?
where exchange takes place
what is the function of the diaphragm?
dome-shaped sheet of muscle that contracts and relaxes to help breathing
what is the function of the ribs?
protect the lungs
what’s the function of the intercostal muscles?
contract and relax to expand or shrink the chest cavity during breathing
where does oxygen diffuse?
oxygen diffuses in the blood
why are alveoli good at gas exchange?
alveoli are good at gas exchange because they have a large surface area, they have a good bloody supply , their lining is moist and they are very thin
what is breathing?
breathing is the process of moving air in and out of the lungs
what are the two muscles responsible for breathing?
intercostal muscle and the diaphragm
what happens when inhaling?
diaphragm- flat contracts
ribs move - up and out
chest cavity - larger
air moves - in
what happens when exhaling?
diaphragm - done relaxes
ribs move - down and in
chest cavity - smaller
air moves - out
what is digestion?
digestion is the breakdown of large insoluble molecules into small soluble molecules and absorption into the blood
where does food go when ur leaves the stomach?
it enters the small intestine which is about 6m long and is a muscular tube lined with specialised cells to digest and absorb nutrients
what do capillaries absorb?
capillaries absorb glucose and amino acids
what happens if the blood vessels in the heart becomes blocked ?
the person suffers from a heart attack
what do valves stop?
the back flow of blood
what are valves supported by ?
valves are supported by tendons which stop the valve being turned inside out
what do the buscupid valves separate
the left artium from the right ventricle
what is breathing?
breathing is the process of moving air in and out of the lungs
where does gas exchange occur?
gas exchange occurs in the alveoli of the lungs
