Test Flashcards
name the pores through which most water vapour is lost from a leaf?
stomata
describe how the guard cells surrounding the leaf pores are adapted to their role?
the cell wall of a guard cell is thicker on one side so the cell doesnt change shape symmetrically as its volume changes.
they can shape and the stoma closes to prevent further water loss from the plant
when water is lost from the cells of the leaf it reduces the ?
water potential
water can be lost in a plant from ?
it’s epidermis layer
water enters cells by?
osmosis
osmosis occurs across the plasma membrane which is ?
partially permeable
if all the water lost from the leaf cells is not replaced, they lose what and wilt?
they lose turgidity
cell division In animals and plants?
cytokinesis
cell division in yeast?
budding
cell division on bacteria?
binary fission
out of animals , plants, yeast and bacterium, which have a nucleus?
animal, plant
material in cell wall?(animal, plant, yeast, bacterium)
animal = none plant = cellulose yeast = chitin bacterium = peptidoglycon
presence of ribosomes in cells(animal, plant , yeast , bacterium)?
all contain ribosomes
name the type of tissue that undergoes cell division to form these undifferentiated plant cells?
meristem
what is not found in mature xylem vessels?
nucleus
cytoplasm
describe how the structure of the cell walls in xylem vessels would differ from the cell walls found at the tips of roots and shoots
thicker
lignified(rigid)
name two types of cells that can be found in phloem tissue?
sieve tube element
companion cell
Explain why the wall of the left ventricle is thicker than the wall of the left atrium?
more muscle on the left side to create more force.
has to create a higher pressure
left ventricle pumps blood further/ to the whole body
How pressure changes in the heart brings the closure of the atrioventricular valve?
ventricular systole muscle contracts,
raises ventricular pressure,
ventricular pressure is higher than atrial pressure,
pressure generated by ventricular contraction closes the valve
what maintains pressure in the mammalian circulatory system?
aorta
What is the transport medium in the mammalian circulatory system?
blood/plasma
Two types of epithelial tissue found in the lungs and airways?
ciliated
squamous
how the alveoli create a surface for efficient gaseous exchange?
wall is one cell thick for shorter diffusion distance.
squamous cells provide short diffusion distance.
maintain concentration gradient.
large number of alveoli to provide a larger surface area.
small size of alveoli provide larger surface area to volume ratio.
Suggest and explain what effect supraventricular tachycardia might have on blood flow from the heart?
less blood leaves the heart for each ventricular contraction,
ventricles do not have time to fill before contracting.
table 5.2
d, c , e , a, b
blood circulatory system of a mammal undergoes changes at or soon after birth, suggest why the foramen ovale is open in the fetus before birth?
lungs not, functioning/filled with air , blood/ haemglobin is, not oxygenated in the lungs/ oxygenated in placenta
fetal haemoglobin q
difference = fetal haemoglobin - higher affinity for oxygen reason = must bind to oxygen, in lower partial pressure in placenta
calculate breathing rate and rate of oxygen consumption
13, 3.6 - 3.1 =0.5
