A man and a woman have a daughter and a son. Their gxzlmd7 frzn 2)0m*z 1/u ar6x*ypm*qdaughter has normal vision, but their son is* d m6a qmx *r1xz0*rfpzz)yul2m 7/ng colourblind. Which one of these genotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic cell in a human mxk58b-iobymgs;g +9 g2ub9 z dale?

  There are two alleles for f:)cojmoewz w9f+jjj(:j y *5 vlower colour in snapdragons. However, the result of a cross between two heterozygous plants yielded offsj5 ye:v :wj9o+ jjj )(o*wmzfcpring with three different observed phenotypes, red, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to kb,j,zp-zw 6s the correct definition?

  Which of these statements is a correct definition fo,on1+nzx,:6e ai(pj4n :mezkl0pjfg r a gene?

  The diagram shows a pair of homologookst z. ,-l; bt kzg1*r4b7oqfv n7(zxt(1iyyus chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a spmcd 4ude- 1.(u ebpsd+m 95iyfecific trait, were crossed in an experiment. Which row shows the expected phenotypic rbm1 +.y4 9 dms-uidu5ec(pefd atios of the offspring resulting from this cross?

  In some animals, the agouti allele causes individual hairs to have a br (v;v uen-nedj(s 9z,anded pattern. The non-agouti allele causes hadsunv,r z (-e;9 j(envirs to be a single colour. Individuals who are heterozygous have hairs with a banded pattern.

Which combination of parent genotypes would allow for production of offspring that do not have the agouti characteristic?

  Mendel observed that the seed shape in individual pea plants was eieze- k6:-ook mther round or wrinkled. The r :ko6zokeem--esults of an experimental cross yielded 315 offspring with round seeds and 105 offspring with wrinkled seeds.

Which row in the table below states the most likely genotypes of the parents?

  Neurons of the fruit fly (Drosophila melanogaster) have ahrf3g5 aly2ndae(yr,+ 2t) n 8 chromosomes. How many chromosomes are in a fertilised oocyta 2dn(5r)ta 2ry+nheayf, l3g e of a fruit fly?

  When does the random orientation of homologous chromosome pairsl. .zncb3f190x 4cyxz; zc wrn occur?

The majority of the genes in the human genome havq(c z:hh ws/9np5c s+fe already been mapped, meaning the exact locations of the gpswcf( zc 9qn:s/h5 +henes on chromosomes are known. The diagram below shows one representation of a homologous pair of chromosomes.

1.Define locus.

2.Identify the number of loci shown in the diagram.

3.Distinguish between gene, allele, and locus.

  Which is the correct definitionflw1 zue), )g wuho23n of linked genes?

  The diagram shows a karyogram of a brown male5 +e)n oq*ckre rat (Rattus norvegicus). Which arrow is pointing to a pair of au5 kr+)e oeqnc*tosomes?

  Mendel observed that there are two possible variations of flower colour in pea pnc:-1lwg: yv8 :d udeglants, purple and white. After a genetic cross, the ratio of plants with purple flowers to dw:n:ld: 8 -cg1euvygwhite flowers is 1:1. What were the genotypes of the parents?

  The graph shows the frequency of birth weight of children born in Londop8jrz bq6ltqtg1fsou*t nt i vi q63i5;4g*2-n in 1991. 3 tq*rvg l uitogn-4tb5 66 q*i2pf;jiq 8z1st

  Which of these traits is an example of continuous variati rpj2e4 7wa.jion?

  Which row correctly describes diploid and haploid ceccb n9g0hui;bebcy.;b1s27 alls in humans?

  The following table shows the diploid chr7xr,,k2j4, kp.a a5bvgbvsze omosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a re fsdz b+vk tj333sbb26cessive allele (Hb$^S$). The dominant allele is Hb$^A$. This image shows the inheritance of sickle cell anaemia in a family.

What are the genotypes for individuals 1 and 7?

  A biological female with blood type A had a child with bloo) +u fy84rs6 kn7hw pjs-ppbi7d type O. What are the possible genotypes of s ) yfrb 6pj spn747pk8u-i+hwthe biological father?

  Which row shows the correct annotation of the all,.f8qj2 ijl o,rwgcv6 eles for blood groups?

  Which of these statements are true for allelexn-(umtxj +a3 xkf/7zs?
I. Alleles are versions of a gene
II. Alleles differ by one or more base
III. Alleles affect the same characteristic

The maps show the incidence of sickle cell anaemia i z::bly*cdss(en0 z vd853 a*.bjfxo and the spread of malaria across the continent of Africa.dc3ox:b* :(8.j*s0bfea z zvl5ns d iy


The graph shows the average density of malarial parasites present in the blood of Hb AA (not affected by sickle cell anaemia) and Hb AS (carriers of sickle cell anaemia) people in Sub-Saharan Africa.

1.Compare and contrast between the distribution of sickle cell trait and malaria in Africa.

2.1.State the mode of inheritance of sickle cell anaemia.

2.2.Using a genetic diagram, determine the probability of a child having sickle cell anaemia, if both their parents are carriers of the disease.

3.Blood samples were taken from children to create the graph. Suggest one difference between the appearance of blood cells in Hb AA and Hb AS samples.

4.State at which age there is the largest difference between the number of parasites found in the blood of Hb AA and Hb AS samples.

5.Suggest one difficulty of collecting sufficient data for this study.

6.Using your own knowledge and the data provided, discuss whether carrying the sickle cell allele offers protection from malaria.

In Mongolian horses (Equus przewalskii), fuh x e5v6 4ykfvc.w-3kftb p4021 sootyr colour is determined by a number of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) colour (P) is dominy f15ov. hck4xkov e fwts420ptb y-36ant to one tone (p).


1.A homozygous sandy ombre male horse is crossed with a heterozygous horse for both traits. Draw a Punnett square to show the potential results of this cross.

2.Identify the possible genotype recombinations, after fertilisation, from the cross in part (a).

3.In pigs, the curly tail is dominant to the straight tail, and pink skin is dominant to black skin. On a pig farm, the resulting phenotypes from double-heteroygous genotype breeding were recorded. The chi-square value for the phenotypes of the offspring was calculated and the result was 340.6.
The table below shows the degrees of freedom (D.f.) and critical values at a significance level (p) of 0.05 (5%) for a chi-squared test.
Discuss whether the genes for skin colour and tail shape in pigs are linked or unlinked.

1.Distinguish between lij bt2xrv,wbx r(j4 /o3nked and unlinked genes.

2.Coat colour is a polygenic trait. State the meaning of polygenic.

Sickle cell anaemia is caused-4 )nyip7 zaumm)yj9g by the allele Hb$^S$ . The normal allele is Hb$^A^ .

1.Identify the genotype of individuals 1 and 2.

2.Predict the probability of individuals 5 and 6 having another child that is unaffected. Justify your answer.

3.If individual 7 had a child with an affected biolgical female, identify the possible genotypes of the child. Justify your answer.

4.Deduce, with evidence, the pattern of inheritance of sickle cell anaemia that is shown in this pedigree chart.

5.Distinguish between sex-linked inheritance and autosomal inheritance in humans.

  The diagram below showsb1hz.-,ngdz kaz+cb ( a cross between a male cat that is homozygous for brown, long dzc ,.+(nhab1g zk-b zhair and a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamond-shytmz9x*27cwk n :h.s rju7+m)kwr1itaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) is dominant over shorzrn uthkmj 9rm7wk:2+1xt.*yc w7i s) t seeds (l).

In a genetic cross between a dandelion that is heterozygous for both traits and a dandelion that is homozygous recessive for both traits, what would be the expected proportion of long seeds?

In guinea pigs (Cavia p**o o+dgh0q .8va t176q;hatkxjsox vorcellus), long hair (L) is dominant to short hair (l), and curly hair (C) is dominant to straight hair (c). A test cross was carried out between male heterozygous long, curly-haired guinea pigs and female short, straight-haired guinea pigs and a chi-squared test (χ2) was carried out on the h*;+.ooqv ajk ovs1 adqt*78th g60xx offspring.



1.1.Using a genetic diagram, state the expected ratio of the cross between the two parents.

1.2.Identify the recombinants.

2.1.Calculate the ratio of the observed phenotypes.

2.2.Suggest a reason for the difference between the expected and observed ratios.

3.1.State the null hypothesis in this study.

3.2.Deduce with reasons whether the null hypothesis should be accepted.

  What best describes the inheritance of the ff22c*xou.dw jkq(9fej2d, dcondition shown in the pedigree chart b2qf2e o9ddkf, jf*u(xw d2jc.elow?

I. Sex-linked trait
II. Dominant trait
III. Recessive trait

  Which of these statements about genetic o:gf.t rd+t)kzzzw9vevm jf 909ort,:e2 q/t disorders is/are correct?

I. The majority of genetic disorders are caused by recessive alleles.
II. Genetic disorders can be sex-linked.
III. Offspring of two parents with the same genetic disease will always be affected.

1.Outline how polygen nd: x*nz)mey2 6euss1ic traits can show a normal distribution.

2.Outline the differences and similarities between homologous chromosomes.

3.Explain why expected and observed Mendelian ratios may differ.

  What suggests that the inheritance of the disorder shown in the pzv3t 4 6zgyzd1 inj1;kedigree chart is X-linked recdt6y11iz 4;zjzgn 3vkessive and not autosomal recessive?

  Different species of living organisms have diav0r45tu/-zvv ur3 nq jxkn* -fferent numbers of genes characteristic to them. The table shows the estimated number of genes for five sp3rtrv 4qu- zax5jv0 / nv*k-nuecies.
Species Estimated number of genes
Escherichia coli (bacteria species) 4,000
Drosophila melanogaster (fruit fly) 13,000
Canis lupis familiaris (dog) 20,000
Homo sapiens (humans) 30,000
Oryza sativa (rice) 40,000
1.Using the information in the table deduce the estimated number of loci in a human genome.
Estimated number of loci in a human is   .
2.Explain how a mutation can affect a characteristic.

  Mendel studied eight characteristics of pea plants2 4nd ave-+p h0lg3knb, including flower colour. If the pea plants Mendel was studying can only be white or purple and follow the rules of Mendelian genetics, which of these statements was correct 02lpad hekn v-+n3b4g?

  A biological male with hemoph.g,ti x)h5zde1w 1p h:cz:qma ilia and a biological female without hemophilia have a daughterpwhtaq dx.h) g 1i5e:m,z1c:z without hemophilia. What are the possible genotypes of the daughter?

  A dihybrid cross was carried out betwe ay) wwxq52h,f0vx oo8. yktu:r:.mv cj+mup0en two sunflower plants (Helianthus annuus) to see if the genes for seed number and seed shape are linked. The critical value 8xf5r: )tqv.hw+.oujy m:y0m pcwv x o2,0kuafor the chi-squared test at the 0.05 significance level was 7.82. The calculated value for the chi-squared test was 10.05; what does this indicate?

1.Explain how parents with blood type A and blood type B can have a chil)h re).7 25ohe*kxtel)te gp )jsgdo/d with blood type O 7)ek*rxogs h))tt)e5pg /eheodl 2j ..

2.Outline how polygenic traits can show a normal distribution.

3.Explain the role of inheritance in genetic diseases.