Module 3 Flashcards
The changes in blood pressure in the right atrium are the same as those in the left atrium. The changes in blood pressure in the right ventricle are different from those in the left ventricle.
(both) atria pump blood to ventricles ; same / short, distance ;
right ventricle pumps blood to lungs ; short distance / at low(er) pressure / at approx 3.2 kPa / at approx 24 mmHg ; ora i.e. (left ventricle) greater distance / high(er) pressure / at approx 15.8 kPa / at approx 120 mmHg less resistance, in lungs or pulmonary circulation / greater resistance in the systemic circulation ; left ventricle pumps to, whole body / AW ; correct ref. to (muscular) walls ; e.g. same (thickness) in atria thicker / thinner, in ventricles more / less, muscular, in ventricles right ventricle pumps with lower / less, force ; ora
Some components of tobacco smoke are absorbed into the blood stream and affect the cardiovascular system.
Describe the effects of nicotine on the cardiovascular system
nicotine increases heart rate ; increases blood pressure ; makes platelets ‘sticky’ ; increases chance of blood clotting / promotes thrombosis ; decreases flow of blood to, extremities / AW ; constriction of blood vessels
Some components of tobacco smoke are absorbed into the blood stream and affect the cardiovascular system.
Describe the effects of nicotine on the cardiovascular system
carbon monoxide combines with haemoglobin / forms carboxyhaemoglobin / higher affinity for haemoglobin (than oxygen); R absorbed, reacts with, bonds to reduces oxygen carrying capacity (in context of, haemoglobin / blood) ; promotes release of damaging free radicals / peroxides / super oxides / oxidising agents ; causes platelets and neutrophils to stick together / platelets to stick to endothelium ; hypoxia can damage heart muscl
Describe the roles of centrioles in animal cells.
(during), mitosis / meiosis / nuclear division ; ignore ‘cell division’ / phases replicate, after / before, each division ; A at interphase move / separate, to poles ; assemble / organise, microtubules ; centre for growth of / forms, spindle fibres / for formation of spindle / AW ; modified centrioles found elsewhere such as in flagella / cilia ;
) Explain why it is possible to see the internal membranes of a cell in electron micrographs, such as Fig. 2.1, but it is not possible to see them when using the light microscope.
(EM has) greater / higher, resolution / resolving power ; ora explanation of resolution as ability to differentiate between two points (close together) ; width of membranes is 7 nm (±1) ; (resolution of) LM is 200 nm (0.2 µm) and EM is 0.5 nm (0.0005 µm) ; A 0.5 to 1 nm (0.001 µm) ref to shorter wavelength ; ora resolution is equal to half the wavelength ;
explain the effect of increasing temperature on the beetroot tissue.
at (temperatures above) 60 °C, cell / vacuolar, membranes damaged / AW; A tonoplast (membrane ) proteins, denatured / altered tertiary structure ; increased fluidity (of membrane) / phospholipid bilayer more fluid ; (so) diffusion / AW, of, betalain / pigment (out) ; as temperature increases, rate of diffusion increases / diffusion occurs more quickly
structure of collagen
more than four (different) monomers (monomers =) amino acids / polypeptides no sugar no base(s) strands not antiparallel peptide bonds no phosphate / phosphorus A sulfur (sulphur) present left handed helix tightly coiled triple helix A three stands
structure of dna
4 (different) monomers (monomers =) nucleotides / polynucleotides double helix right handed helix loose helix sugar antiparallel strands phosphodiester bonds base(s) phosphate / phosphorus
State what is meant by the term tidal volume.
volume of air breathed, in / out, with one breath
Explain how the minute volume at rest would be determined
before / after recovery from, exercise ;
either measure tidal volume, by breathing out into a bag ; multiply by number of breaths per minute ; A total tidal volume in x minutes ÷ x
or use a spirometer / described ; ref to taking recordings from a trace / use of a, kymograph / datalogger
Suggest two differences in the structure of the lungs that may account for the greater oxygen uptake by people who live on top of mountains
(bigger lungs so) more alveoli ; A greater surface area (of alveoli) more, bronchioles / airways ; R more bronchi wider, bronchioles / airways ; larger number / higher density, of capillaries (around alveoli) ; thinner wall / shorter distance, between air and blood / AW ;
Explain why the red blood cell count increases so much when people visit places at high altitude.
partial pressure of oxygen is low ; A low concentration of oxygen / less oxygen more haemoglobin (is required / produced / synthesised / available) ; compensates for smaller volume of oxygen absorbed / compensates for lower saturation of haemoglobin / more oxygen can be carried (per unit of blood) ; ref to, EPO / erythropoeitin ;
Suggest how organisms that live in freshwater that has a low concentration of sodium ions. and who’s body fluids have a higher concentration of sodium ions than the surrounding water, retains sodium ions in its body fluids.
cell membranes impermeable to sodium ions ; (as) sodium ion channels are not present (in cell membranes) ; active transport / active uptake ; A sodium pumps to take up sodium ions move sodium ions against their concentration gradient ; uses, energy / ATP ;
State one role of sodium ions in organisms.
ref. to, (nerve) impulses / action potentials / depolarisation / resting potential ; treat ref. to electric as neutral helps to maintain, water / solute / osmotic, potential of, body fluids / named body fluid ; helps to maintain, osmotic / electrolyte, balance ; ref. to, urine formation / osmoregulation ; absorption of glucose / co-transport ; [1 max]
flatworm which lives in ponds, streams and rivers. The dimensions of the flatworm are 12.5 mm long by 3.0 mm wide. Its volume was estimated as 12.6 mm3. Flatworms do not have a transport system for the respiratory gases, oxygen and carbon dioxide.
explain how flatworms survive without a transport system for respiratory gases.
thin / flat ; large / high, surface area to volume ratio / small / low, volume to surface area ratio ; R large surface area (on its own) (SA:V ratio) 5.95:1 ; A anything between 5:1 and 7:1 or suitable calculation e.g. 2 × (12.5 × 3.0) / 12.6
state two ways in which the structure of catalase is similar to the structure of haemoglobin and one way in which it differs
similarities
made of amino acids / amino acid monomers / polymer of amino acids A protein / polypeptides have quaternary structure / have more than one polypeptide chain ; four, sub-units / polypeptides ; haem / porphyrin / prosthetic group(s) ; [2 max]
difference
(four) sub-units / polypeptides, are identical ; or haemoglobin has, two different, sub-units / polypeptides ; or haemoglobin has alpha and beta polypeptides ;
(catalase) has active site(s) ; A Hb has (oxygen) binding site
State why it is possible for a catalase molecule to bind to four substrate molecules at the same time.
each, sub-unit / polypeptide, has an active site ; catalase has four, active sites / haem groups ;
Explain, in terms of water potential, how water moves from across the leaf
water moves down water potential gradient ; A high(er) to low(er) water potential / less negative to more negative water potential apoplast pathway / through cell walls ; symplast pathway / through, plasmodesmata / cytoplasm ; evaporation ; from spongy mesophyll cell walls ; into (substomatal / intercellular) air space ; diffusion of water vapour ; A diffusion of water if evaporation used in correct context elsewhere through stomata ;
State and explain three ways in which the structure of xylem vessels is adapted to transport water.
cellulose, cell wall / lining ; allows adhesion of water ; and prevents collapse providing support under tension
either lignin ; waterproofing / prevents water loss ; or lignin ; A rings / spirals / thickening / AW (of walls) prevents collapse / idea of providing support (under tension) ;
no cytoplasm / lack of contents / hollow / empty lumen ; R dead less resistance to / unimpeded / uninterrupted / unhindered / ease of / AW, flow / AW ; A greater volume per unit time / faster rate R continuous, smooth
lack of end walls / continuous tube ; less resistance to / unimpeded / uninterrupted / unhindered / ease of / AW, flow / AW ; R continuous, smooth
pits / pores ; R holes lateral movement / movement around air bubbles / supplies (water) to (surrounding), cells / tissues ;
wide / large diameter / large lumen ; so large volume of water can be transported ;
how do you know a cell is in metaphase
chromosomes / chromatids, on equatorial plate / at equator / AW ; A in, centre / middle, of cell nuclear, membrane / envelope, dispersing / breaking up / (partially) visible / AW ; A disappearing chromosomes, in one group / not in two groups / not arrow shaped / not going to poles / not separated / AW ;
Describe how cigarette smoke is responsible for the development of lung cancer.
smoke / tar, is carcinogenic
genes control, cell division / mitosis ;
mutation / change to DNA (in these genes) ;
tumour suppressor genes switched off cells,
uncontrolled mitosis
cancer cells do not respond to signals ;
(and) form a (malignant) tumour ;
(tar) settles on bronchial, epithelial cells / epithelium ;
State and explain two ways in which the structure of a phloem sieve tube is adapted for the transport of assimilates.
sieve pores ; allow easy flow (from sieve tube element to sieve tube element) ; R flow of water
sieve plate ; (may) prevent sieve tubes from bursting / AW ;
cell (surface) membrane / plasma membrane ; prevents loss, of sucrose / assimilates / phloem sap ; little cell contents / AW ; R no cell contents little resistance / AW, to flow ; R flow of water
plasmodesmata ; allows flow, to / from, companion cells ;
thin walls ; for, rapid / easy, entry of water (at source, to build up pressure)
Describe the function of the endodermis in roots.
Casparian strip / suberin, is impermeable (to water) ; blocks, apoplast pathway / pathway between cells / cell wall pathway ; ref. to passage cells ; water / (inorganic) solutes / minerals / ions, must pass through, endodermal cells / symplast pathway / symplast pathway described ; cell can select solutes / AW ; ref. to, active transport / carrier proteins ; ref. to presence of solutes (at base of xylem) causing increase in root pressure / AW
State two roles of water within plant cells other than taking part in breakdown reactions
accept any two relevant examples, e.g.
solvent / medium for reactions ;
transport medium ;
maintaining turgidity / keeping firm / prevents flaccidity / AW ;
(raw material / reactant for) photosynthesis / photolysis ;
expansion / elongation / growth ;
maintains, hydrostatic pressure / pressure potential ;
maintains water potential (gradient) ;
A maintains osmotic gradient / prevents plasmolysis
stomatal opening ;
hydrophilic interactions of membranes ;
(in vacuole) pushes chloroplast to edge of cell ;
R hydrogen bonding unqualified by ref. to membranes