module 3 Flashcards
name 4 substances and organism needs to exchange with its environment
oxygen, glucose, carbon dioxide and urea
what is the relationship between surface area and volume ratio of an organism
smaller animals have a higher surface area: volume ratio
what are the 4 specialised features of efficient gas exchange surfaces?
thin layers, large surface area, good blood supply and good ventilation
what is the function of a goblet cell?
to secrete mucus to trap microorganisms and dust/ dirt
what is the function of cilia
beat the mucus upward away from the alveoli towards the throat to prevent infections in the lungs
what is the function of elastic fibres?
to help breathing out, the fibres recoil on breathing out and help push the air out
what is smooth muscle for?
allows diameter of trachea, bronchi and bronchioles to be controlled
what are the rings of cartilage for?
provide support to the trachea and bronchi to stop them collapsing when breathing in
what is meant by tidal volume and vital capacity
volume of air in each breath and maximum volume of air that can be breathed in or out
what’s the function of the gill plates and gill filaments in fish?
both of these feature increase the surface are a for exchange of gases
what is the structure on an insects surface that allows air to enter the tracheae
spiracles
3 reasons why multicellular organisms need a transport system
low surface area to volume ratio, higher metabolic rate, very active = large number of cells that are respiring very quickly
why is the mammalian circulatory system described as double circulatory system
the blood passes through the heart twice
what is an open circulatory system
blood isn’t enclosed in blood vessels all the time instead it flows through the body cavity freely
is the blood pressure highest in veins or arteries
arteries
what do the vales in the hart prevent?
the blood from flowing the wrong way
what side of the heart pumps oxygenated blood around
right side
what prevents the impulse from the atria travelling straight to the ventricles
a band of non conducting collagen
what causes the QRS part of an ECG trace
the contraction of the ventricles
how many oxygen molecules can haemoglobin carry
4
what is carbon dioxide converted to in red blood cells
carbonic acid
why doe multicellular plants need transport systems
need substances to be delivered and taken away
what is the name of the substance that thickens the wall of the xylem vessels
lignin
what is the function of companion cells
companion cells carry out the living functions for both themselves and their sieve cells
