IB Biology D4 1 Natural Selection Question Bank

\(P a n \mathrm{I}^{\mathrm{A}} 0.75\) and \(P a n \mathrm{I}^{\mathrm{B}} 0.25 / 3 P a n \mathrm{I}^{\mathrm{A}}\) to \(1 P a n \mathrm{I}^{\mathrm{B}}\) Both must be correct for the mark to be awarded, accept frequencies in form of ratio.

(cod with) \(\operatorname{PanI}^{\mathrm{A}}\) allele selected/favoured/better adapted to warmer water; (cod with) PanI \({ }^{\mathrm{B}}\) allele selected/favoured/better adapted to colder water; cod that survive can reproduce and pass alleles on to offspring; It takes a whole organism to reproduce in order to pass on the allele, hence we expect reference to the fish to gain this last marking point

higher frequency of \(\operatorname{PanI}^{\mathrm{A}} / \operatorname{PanI} \mathrm{I}^{\mathrm{A}} \operatorname{PanI} \mathrm{I}^{\mathrm{A}}(\operatorname{cod})\) in warm (surface) water; higher frequency of \(\operatorname{PanI}^{\mathrm{B}} / \operatorname{PanI}^{\mathrm{B}} \operatorname{PanI}^{\mathrm{B}}\) (cod) in colder (deeper) water; interbreeding results in \(\operatorname{PanI}^{\mathrm{A}} \operatorname{PanI}^{\mathrm{B}} \operatorname{cod} /\) heterozygous cod;

a. older/skilled women could provide more food when they no longer reproduce; b. this could provide more food for offspring/group leading to greater success for the group; c. (in competition with other groups) this group would survive to pass on the genes for menopause; d. allows younger women to use time/energy to reproduce and care for offspring;

evidence that fructose causes (body) fat accumulation/obesity; evidence that fructose is related to increased (blood) triglycerides which are correlated with obesity/coronary heart disease; evidence that fructose is related to reduced insulin sensitivity/diabetes; evidence that fructose is used in ribose synthesis but no clear evidence that fructose causes pancreatic cancer;

high epidemic sizes associated with higher populations of D. dentifera/Daphnia; the greater the population of D. dentifera/Daphnia, the greater the possibility of variation/mutations in population; some of the variations may include greater resistance to the parasite; (resistant strains) have a greater chance of reproducing/produce more offspring; (leads to) selection in favour of resistant strains / death of non resistant strains;

a. directional selection is when an extreme phenotype/characteristic is favoured b. flies that form small galls will be selectively predated c. over time, flies that produce small galls will become rarer OR mean gall size will increase OWTTE OWTTE - accept vice versa 2 max

a. mutant aphids/varieties may be indifferent to/attracted to transgenic plants as these do not present a hazard «not favour» \(\boldsymbol{}\) b. initially/for limited time the plants would thrive as the aphids would be «largely» repelled and thus not eat the plants «so natural selection would favour them» c. over time/in a few generations, the aphids population become more resistant/more attracted/less repelled to EBF and return to feed on the plants so long-term benefit very limited «so natural selection would not favour them» \(\boldsymbol{}\) d. the aphids resistant to EBF would not respond to other aphid alarms and «likely» be more readily eaten by predators «so the long-term benefit to plants could be supported by natural selection» The answers must indicate whether natural selection would support or not for each statement.

a. when there is more food available the elephants are willing to share/cooperate OR when food is scarce, survival/competition is more beneficial than cooperation OR natural selection will favour the behaviour that gives elephants sufficient food; b. the elephants may not behave in the same way in the wild; OR controls are not specified/how much food was available was not given/gender of elephants/sizes/ages/whether or not the same elephants were used for the trials;

D2. (a) large population; randomly breeding population; no mutation; no selection (for an allele); no migration/immigration or emigration;

heterozygotes have two alleles \(/ \mathrm{Hb}^{\mathrm{A}} \mathrm{Hb}^{\mathrm{S}}\) which gives them (partial) resistance to malaria; heterozygotes \(/ \mathrm{Hb}^{\mathrm{A}} \mathrm{Hb}^{\mathrm{S}}\) more likely to survive and reproduce than either homozygote \(/ \mathrm{Hb}^{\mathrm{A}} \mathrm{Hb}^{\mathrm{A}}\) and \(\mathrm{Hb}^{\mathrm{S}} \mathrm{Hb}^{\mathrm{S}}\); \(\mathrm{Hb}^{\mathrm{A}} \mathrm{Hb}^{\mathrm{A}}\) may die from malaria \(/ \mathrm{Hb}^{\mathrm{S}} \mathrm{Hb}^{\mathrm{S}}\) are more likely to die from sickle-cell anemia; an equilibrium between allele frequency is established / lethal allele retained in population;

Hardy-Weinberg equation (e.g. \(\mathrm{p}^{2}+2 \mathrm{pq}+\mathrm{q}^{2}=1\) ) / calculation of p (e.g. p=1-q=0.98 ) \(/ \mathrm{p}^{2}=0.9604\); calculation of total of babies without allele \(=\mathrm{N} \times \mathrm{p}^{2}\) or \(281884 \times 0.9604=270721\);