Cells
➢ Non-polar amino acids cause proteins to
remain embedded in membranes=falsifies
Davson-Danielli model since look at ending of
phrase
➢ Be careful with magnification (make sure to
convert, use correct sig. digs, check units)
➢ Surface area to volume ratio as cell
grows=decreases, so rate of gas exchange is
too low
➢ Lysosome has a single membrane; nucleus,
mitochondria, chloroplast have double
➢ Smaller space between phospholipids +
glycolipids attached to phospholipids
➢ Hypertonic=water out, hypotonic=water in (low to high solute, since high to low water)
○ Animal: lysed, normal, shrivelled
○ Plant: turgid (normal), flaccid, plasmolyzed
➢ Specific terminology
○ Structure of phospholipids=fluidity and ​cholesterol​ (temperature range)
○ Mutually beneficial​ for endosymbiotic theory
➢ Facilitated diffusion for polar/​charged
➢ Tumour suppressor genes normally cause cell apoptosis and repair cells
➢ State=one word
Molecular Biology
➢ Read questions thoroughly
○ 4 nucleotides vs. 8
○ Some proteins have more than one polypeptide chain (genes just contribute with Central
Dogma, but polypeptide chains can go together to form other proteins)
➢ Make educated guesses if unsure
○ Lipase=lipids, glycerol and fatty acids make up triglycerides
➢ Explain/annotate diagrams if you include them (Sections of pH graph, show how work)
➢ Both DNA and RNA rely on complementary base pairing, DNA in nucleus but RNA isn’t
➢ When describing hydrolysis of molecule, discuss enzyme + put over arrow in equation
➢ DNA replication: DNA polymerase attaches to the exposed bases to begin elongation on both
parallel strands, moving in the 3’-5’ direction, then it facilitates the addition of complementary
base pairing using the nucleotides, building 2 daughter strands in the 5’-3’ direction
○ Lagging=away from helicase, thus made in segments
➢ Pay attention to get numbers within accepted range
➢ Better graph interpretation=qualify/quantify, talk about other factors, use correct graph
➢ Use “likely” (not certain) to explain possible graph analysis
➢ DNA diagram: phosphodiester bond between nucleotides, 5’ at top left, nitrogenous bases (not
nucleotides, that is the entire molecule), AT has 2 H-bonds and GC has 3
➢ pH changes charge of enzyme, which changes the shape of the active site
➢ Careful when drawing diagrams (O in middle of maltose because water is created)
Genetics
➢ Read question (mutation for sickle cell in brain cells, long chromosomes with centromere=2)
➢ Make sure to list ​all possible genotypes
➢ Simple answers best: “X would only supply I^B or i” instead of drawing all squares/paragraph
➢ ACGT/U are nitrogen bases NOT nucleotides
➢ Be careful with specific wording
○ “Altering single DNA base” means not deletion/insertion
➢ Word answers purposefully and state the obvious
○ Sex chromosomes control sex characteristics
➢ Hemophilia=X-linked recessive
➢ Independent assortment=metaphase I (not II) with 2^23 possibilities
➢ Not in colour (not seen when scanned for IB)
➢ Stem cells=undifferentiated
➢ Vvcc x vvCc have 1:1:1:1 ratio (not just 1, needs to produce all phenotypes)
➢ Estimated genes in human gemore=25,000
➢ Codon=sequence of nucleotides on mRNA that correspond to an amino acid
➢ Nonsense=stop codon, Sanger technique is to sequence DNA
➢ PCR=heat breaks H-bonds, Taq polymerase attach nucleotides, ligase for phosphodiester bonds
➢ X-linked recessive=common in males, female can be carrier, female has affected father/sons
Ecology
➢ Trophic level=feeding level (need space between to count as feeding, thus need 4 organisms for 3
trophic levels)
➢ Nutrients ​cycle between biotic and abiotic environment
➢ Use simple phrases/not necessary to what question is asking
○ “warming of atmosphere by trapping longwave radiation”
○ Specific terminology: “no statistically significant relationship”
➢ Fluctuate over time=cyclic
➢ Degree of freedom (chi-squared) is 1 for quadrats (even though 3 for genes)
Evolution
➢ Terminology: “endothermic”, “prokaryote” for archaebacteria, “selective pressures” for struggle
for survival”, variation due to ​mutations
➢ Prokaryotic=70S ribosomes, flagella is extension to cell so contains cytoplasm
➢ Read (letters for spots of dichotomous key)
➢ Organization=keep information together, give examples, bullet points
➢ Bryophyta and filicinophyta produce spores
➢ Hardy Weinberg=changes in allele frequency over time, different is evolution, snapshot of gene
pool, q^2=recessive genotype and q=frequency of recessive allele (vice versa for dominant)