Wrong Flashcards
Explain why a mammal born with a hole between two ventricles becomes tired with lack of enegry 3m
• less oxygen available for aerobic respiration
• deoxygenated blood mixed with oxygenated blood
• reduces concentration of oxygen in vlood
Explain how a diet of a person could affect development of CVD 3m
• damage to endothelium
• Hugh LDLs link to plaque forming
• high intake of cholesterol= high LDL
Explain how athersclorisis can cause damage to heart muscle 3m
• narrowing of lumen
• reduces blood flow
• reduces aerobic respiration
Describe the role of thrombin in blood clotting 3m
• thrombin is an enzyme
•which catalysed the conversion of fibrinogen into fibrin
•a mesh of fibrin traps platelets to form a blood clot
Explain how a blood clot can form in a blood vessel 4m
• blood clots form when collagen is exposed if the walls of a blood vessel is damaged
• leading to release in thromboplastin
• thromboplastin catalyses the conversion of prothrombin into thrombin
• thrombin catalyses conversion of fibrinogen into fibrin
• fibrin forms a mesh of fibres + traps platelets to form a clot
Explain how platelet inhibitors would reduce risk of heart attack 2m
• platelet inhibitors reduce risk of blood clotting
•so less likely for blood clot to block arteries
Devise a procedure for measuring heart rate daphnia w caffeine
• daphnia immobilised on cavity slide
• acclimation time as a control in caffeine solution
• use diff concentrations
•use a method to count heart rate
•use daphnia of same sex size species as control
• repeat calc for mean
Explain how pressure differences in headset ensure efficient pumping of blood into arteries 4bp
• pressure increases in ventricles
• greater pressure in ventricles than in atria
• causing atrioventricular calves to close
• causes semilunar valves to open forcing blood into arteries
Compare and contrast the process of transcription w process of dna replication 4m
• both use enzyme helicase to unzip dna
• both involve formation of phosphodiested bonds
• transcription uses RNA nucleotides
•replication uses DNA polymerase
Explain how a change of one amino acid could lead to a change in the
structure and properties of the haemoglobin protein. 4 m
• change in primary structure
• diff amino acids will have diff R groups
• secondary structure will change
• may not bond to haem
Describe the role of tRNA in production of …3m
• trna molecules transport amino acids to the ribosome
• trna molecule has an anticodon that binds to a codon on the MRNA
• each tRNA carries a particular amino acid
Describe how the primary structure of leptin enables it to be soluble in water ,
• primary structure of amino acids determines the folding of the polypeptide
• forming a globular structure
• hydrophobic R groups located in centre of protein + hydrophilic R groups located on outsides
• hydrogen bonds form with the hydrophilic R group
Describe how a frameshift mutation could result in the production of lepton (anything) w a shorter primary structure 3m
•adding or removing one or two nucleotides changes the triplet code so diff codons produced
• introducing a new star/ stop codon
• coding for a shorter sequence of amino acids c
Describe how translation leads to production of polypeptide 5m
• mRNA binds to ribosome
• ribosome finds start codon
• tRNA has specific anticodon, complementary to codon so they bind
• ribosome moves along to next codon
• amino acids join by condensation reactions to form polypeptides
Compare and contrast endocyyosus and exoytosis 3m
• both require energy from ATP
• both involve vesicles
• exocytosis is molceucles leaving cell whereas endocytosis is molecules entering cell
Explain some of the symptoms a person w cystic f could have 6m
• mucus thicker than normal
• pancreatic enzymes cannot whether intestines coz pancreatic duct blocked w mucus
• high energy diet required coz digestion less efficient
• pancreatic enzymes trapped behind mucus damage pancreatic cells such as those that produce insulin
• cysts form in pancreas
• sperm cannot leave testes coz sperm duct blocked w mucus
• gene mutation
• non functioning CFTR protein channel
• chloride ions cannot move out of epithical cells
• accumulation of sodium and chloride in cells prevent water mocing into mucus
Definition of allele
• caused by a faulty allele that is only experessed in absence of normal allele
State what is meant by term allele 2m
• diff version of a gene
• found at same locus on chromosome
Describe role of TRNA in production of leptin 3m
• trna molecule transports amino acids to ribosome
• trna molecule has anticodon that binds to a codon on the mrna
• each trna carries a particular amino acid
Describe how the primary structure of leptin enables it to be soluble in water 3m
• primary structure determines the folding of polypeptide
• forming globular structure
• hydrophobic R groups located in centre and hydrophilic outside of protein
• water forms hydrogen bonds with the hydrophilic
Explain why diff mutations have diff effects on protein structure 4m
• deleting could affect every codon on MRNA whereas substitution will only affect one codon
• deletion more likely to affect position of stop or start codon
• deletion results in a diff sequence of amino acids/ substitution may not affect the sequence of amino acids
• substituoon may code for same amino acid
•
Same amino acid due to degenerate nature of genetic code
Deduce what happens to lactate in these cells after liver cells absorb lactate in blood 2m
• lactate in oxidised to form pyruvate
• pyruvate conveyed to glucose
Explain the importance of primary structure for functioning of enzyme 3m
• primary structure determines interaction between R groups
• primary structure determines folding and 3D shape
• thus shape of active site is affected
Explain how a single base mutation can lead to an altered primary structure of enzyme G
• change in base results in a change in triplet code
• this changes codon in MRNA
• resulting in diff amino acid sequence
Describe what happens to these proteins following the process of translation until they are released from the cell 3m
• proteins folded in rough w do plastic reticulum
• proteins then packed into vesicles
•proteins modified in in Golgi apparatus
• exoytosis
Compare and contrast molecular structures of globular and fibrous proteins 4m
• both are long chains of amino acids joined by peptide bonds
• both contain hydrogen bonds holding tnem in shape
• globular proteins have hydrophilic groups on outside whereas fibrous have hydrophobic on outside
• fibrous proteins are long chains globular proteins are folded compactly
Explain why the nucleus cannot be observed at the end of prophase in eukaryotic cell 2m
• because the nuclear membrane is broken down
• coz dna is coiled into individual chromosomes
Describe how polypeptide chain is processed to make AFGP 4m
• polypeptide chain moves through endoplasmic reticulum then the Golgi apparatus
• in the RER (rough endo) the polypeptide chain in folded
• in Golgi apparatus carbohydrate added
• polypeptide chain then transported around cell in vesicle
What is function of plasmodesmata 2m
• cytoplasmic connection between cells
• allows communication
Describe the events of fertilisation that occur after the acrosome reaction
• fusion of sperm cell membrane with egg cell membrane
• cortical granules release contents into zona pellucida
• contents of cortical granules react w zona pellucida and it thickens
• fusion of sperm and egg
Explain why offspring may be genetically different even w same dad and mum 2m
• difference gametes
• each gamete contains diff combintuaoons of alleles
Explain why a second sperm cell cannot fertilise the egg cell 3m
• cortical reaction- fusion of cortical granules with egg cell surface membrane
• resulting in thickening of zona pellucida
• therefore other sperm cells can’t reach egg cell surface membrane
Explain what is meant by a sex linked disorder 2m
• disorder caused by a mutated gene
• on x/y chromosome
• so disorder more likely in one gender than igher
Explain how vesicles are involved in the successful fertilisation of an egg cell by only one cell 2m
• cortical granules fuse with egg cell surface membrane
• releasing enzyme that hardens the zona pellucida
Describe how meiosis leads to genetic variation in the gametes produced 2m
• produces non indenfuxak gamete’s due to indepdeng asornement of chromosomes
• crossing over between chromatids
Explain why some genes show linkage and others shiw sex linkage 3m
• there are more genes than chromosomes
• linkages relate to genes for diff characteristics located on same non sex chromosome
• sex linkage relates to genes in x/y chromosome
Explain how crossing over and independent assortment can produce gametes w new combinations of the alleles shown on the diagram of the 2 pairs of chromosomes 4m
Crossing over
• chromatids are produced w diff combinations of alleles
• eg Ab/aB
Independent assortment
• diff combinations of chromosomes r produced
•therefore alleles for A and B could be in same gamete as C or c
Explain how crossing over may differ in sex chromosomes 2m
• crossover cannot form between some sections of the x and Y chromosome
• coz they are not homologous chromosomes
Explain why dna is replicated before mitosis begins 2m
• to ensure diploid number of chromosomes in each daughter cell
• to ensure daughter cells r genetically identical
Explain how large numbers of cells.with the same phenotype can be produced in a tissue 2m
• phenotype determined by the genotype + effect of environment
• mitosis produces cells with the same genotype
Explain why the nucleus cannot be observed at the end of prophase in a eukaryotic cell 2m
• because nuclear membrane is broken down
• coz dna is cookies into individual chromosomes
Describe how the acrosome is involved in digestion of zona pellucida
• membrane of acrosome fuses with membrane of sperm
• releasing enzymes from acrosome by exocytosis
Describe the events that occur during prophase in an animal cell 3m
• nucleus breaks down
• spindle fibres formed
• centrioles migrate to opposite poles of cell
Describe role of acrosome in fertilisation 3m
• acrosome fuses with the cell surface membrane of the sperm cell
• digestive enzymes released
• to break down zona pellucida
Describe appearance of chromosome in the cells undergoing metaphase 3m
• visible
• seen as pairs of chromatids held together by a centromere
• joined to spindle fibres aligned in middle
Describe how clinical trials of a vaccine would be conducted 3m
• small groups of healthy volunteers given drug to see side effects
• healthy volunteers tested for presence of antibodies
• a group of ppl at risk of contracting diseases given vaccine
• n. Ppl who get disease aftwr vaccine monitored
Describe the role that zoos play in animal conservation 3m
• zoos protect animals from hunters
• breeding programmes in place to increasee numbers
• used for research purposes or educating
3 phases kn drug testing + what they do 3m
• phase 1 to test if drug to make surenot harmful
• phase 2 to see if effective in treating illness
• phase 3 to gather as much info from statistical tests
Describe structure of starch 3m
• is a polysaccharide made from alpha glucose
• monomers held by 1,4 glycosidic links
• starch contains unbranched amylose chains and branched amylopectin chains
• branches joined to chains by 1,6 glycosidic links
Explain the role of the middle lamella when a plant cell completes mitosis 2m
• produced between adjacent new cells
• because middle lamella holds cell walls together
