A man and a woman have a daughter and a son. upju7n e:1hcp7s, 9eo,fxep 8Their daughter has normal vision, but their son is colourblind. Which one of ,ep fc oux e1:jhpe s,nu78p79these genotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somati ey9m28 dgfixu+koodo57v.j; c cell in a human male?

  There are two alleles for flower colour in snapdr ds)hgo0ddg 4a+4(swm+gqn y :agons. However, the result of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red, white and pink flowers. Wh)n:(amo dyggs g4wd+4 sd hq+0ich is the most likely explanation for this observation?

  Which keyword is matched to the correct definit4mxd+p a+q 1le.w-8pm2hw q hsion?

  Which of these statements is a correct definitios0cxl. kmku- )0ujiid7 ut uo245wr /xn for a gene?

  The diagram shows a pair of homologous j 6fay)dyvkfk bj435,4nepp7chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were crossed in an exper 38d /i,iemlqvoir6.b iment. Which row shows the expected phenotypic ratios of the of i qmo r36d8.vebli,/ifspring resulting from this cross?

  In some animals, the agouti allele causes individhh..c1v:equ wual hairs to have a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who are heterozygous have hairs with a bande ec:.v.uw hq1hd pattern.

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

  Mendel observed that the seed qkvxhy 7g; (/j)/ k2uaj: )gvsqk3rkgshape in individual pea plants was either round or wrinkled. The results of /k)q: 3/ (v7ghj xrsa 2;g kykukvgq)jan 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 8 chr.jhr 0t q.y4oqomosomes. How many .t ho40qrj qy.chromosomes are in a fertilised oocyte of a fruit fly?

  When does the random orientation of homologous chmy5ig 6:5v2c4kwh 6fy mqqb u/romosome pairs occur?

The majority of the genesfcc-tipfv 5/3 in the human genome have already been mapped, meaning thf/vftc-5p 3ci e exact locations of the genes 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 definit ,*j pka+4dp-+evx ciuion of linked genes?

  The diagram shows a karyogram of az15a( 46rljvctyb*m d brown male rat (Rattus norvegicus). Which arrow is pointing to a pair of autosomyav( 65mrt jc4lb d1z*es?

  Mendel observed that there are two:0)niy2kbmdw,:v l g l possible variations of flower colour in pea plants, purple and white. After a genetic cross, the ratio of plants with purple flowers to white flowers )d: :2my,biwnv lgkl 0is 1:1. What were the genotypes of the parents?

  The graph shows the frequency of birth weight o.th apgf9 b/f9f children born in London in 1991p/at.9bfhg f9.

  Which of these traits is an example of continuous09)ok m)qu*fm7)cwl f zzmic : variation?

  Which row correctly describes diploid a h d,7i:lq(xe9dyqiavh9c.x1nd haploid cells in humans?

  The following table shw s*f/q( 7w1os/vppb;ch : tqmows the diploid chromosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessiy78e jyp;(uzfpn e*;y ve 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 blood type Or ,3zkke4oalq t e0w5v72.s.t0zup dl. What are the possible genotypes of lw0opts.lz 5kedr 7.3kq4uvea,02 tz the biological father?

  Which row shows the correct annotation of the alleles for blon)kbtl*h (k h:dielc-m/0+n,p ;f eqm od groups?

  Which of these statement pjr9no-:79u(yshusl s are true for alleles?
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 incidlxb8-b2n p .lq rzy4s2ence of sickle cell anaemia and the spread of malaria across the continent of Africa. . nsx22bpyr4b l8-lqz


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 przewalskiiwy/g;orsww*nn ulnhk;/ *-3 y), fur colour is determined by a number of gene-h*/y;ns3 wn ywwo/r lg *ku;ns. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) colour (P) is dominant 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 linked and unlinked-pvows.ahhhn-*93 hl/ nzr5 z genes.

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

Sickle cell anaemia is caused by the uf e hf5bzq k:6:nau4ic5y1(j 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 shows a cross between a m*1oe1 dkm6 ;x(t-bcs;sam1pw oug qf5ale cat that is homozygous for brown, long hair and a female cat that has black, short haiub dfsapmo(*e;o;11qcg5 6 mwxst- 1 kr.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacunfzq :a:y 8fju sa(ul)9605co8eo gv jm officinale), the allele for diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) o5:vclfqe 96 o0a )z( u8 s8af:ujgjnyand the allele for long seeds (L) is dominant over short 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 porcellus), long hair (L) is dominant to shm1x4x 2bq+ xmbn-em jnnp(3m s:q)n4oort 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 tesbm: q2-emx1 mbp(3qxnns)n 4j 4oxn +mt (χ2) was carried out on the 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 conditio: eg z;39xhxtjn shown in the pedigree chart belgh xjt; 9xze:3ow?

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

  Which of these statements about gene9 2 dm vy*nrrloz55tu6/fprq/tic 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 polygenic jj2xy1e 3n8/0ek w q oyf-jdf+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 th (gfw1x) cvl*pnv8p y2e inheritance of the disorder shown in the pedigree chart is X-linked w 1( xvp8vl*n2cy) gfprecessive and not autosomal recessive?

  Different species of living organisms have diffe /, x p4*bqvkkp:3vbxo ua,f0arent numbers of genes characteristic to them. The table shows the estimated number of genes for five specbx: x 4a30p qopb,kfvk/*va,uies.
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 plants,:s(0kz) k1cmzd ah/4cn..lu p 7qgeuk including flower colour. If the pea plants Mende/)k:edkq n4cz. c7mzka u1(usg.h0pll was studying can only be white or purple and follow the rules of Mendelian genetics, which of these statements was correct?

  A biological male with hemophilia and a biological female without hemophilia havrv0xd.( j5poq *kzvf7e a daughter without hemophilia. Wha.dr jf*ov 057vz(k pxqt are the possible genotypes of the daughter?

  A dihybrid cross was carried out between two sunflower plants (Hch5y:1.8f3 z dv.mgy w w0it hvy--pawelianthus annuus) to see if the genes for seed number and seed shape are linked. The critical value for the chi-squared test at the 0.05 signific1whp-ivv .hg83f5zdw0.c-y ta:m ywyance 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 cac ,q0mn xu9u.6t oj4uhn have a child with blood cnjuq.mtuh0 u9o, 4x6 type O.

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

3.Explain the role of inheritance in genetic diseases.