A man and a woman have a daughter and a son. Their daughter has normal vision, b3855xrs v- p0xcndkgr ut their son is colourblind. Which one of these genoxvpc 80 k53dx-rnr s5gtypes could be correct for the biological mother?

  Which diagram shows the sex chrthndax1+tj*q, vr r8. omosomes of a somatic cell in a human male?

  There are two alleles 3ils)ngi b7o4af8;h ufor flower colour in snapdragons. However, the result of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red, white an) 7go3 s4ai8fluni bh;d pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to the mn)zfze .i +m 85xv1tmhjd 0)wcorrect definition?

  Which of these statements is a correct definition for a pfo59 d/+ubfc gene?

  The diagram shows a pairoqaif )9 d8i1pd85or ezdxk+0 of homologous chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were crossed in an expeqfg/cn5(6xomhv (2 ps riment. Which row shows the expected phenotypic ratios of the offspring resulting from tgohc65 s(mx q/ 2n(pfvhis cross?

  In some animals, the agouti allele causes ind jy xnyq:;16llw 0x0gl0pgz(lx j9d. qividual hairs to have a banded pattern. The non-agouti allele causes hairs to be a single colou;.0y60lzy0ljgxqdl9pg nqj xx1 w(: lr. 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 e a58cod2qdiis42 q0ezu) rs,shape in individual pea plants was either round or wrinkled. The results of an experimental cross yielded 315 offspring with round seeds and 105 offspring5i di2u)dr , sq8ec4e2oqs 0az 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 chromosomes. How :t yt,(lq rn e 7s+d2* wfyychlfarmx;4c7t+6many chromosome( 7e fw;dt 4+*+an2q6 :s7h,ryytfmct ylrxlcs are in a fertilised oocyte of a fruit fly?

  When does the random orientation of homologous c.g+x i+k) ijfoo(* z 3zqo,gqkhromosome pairs occur?

The majority of the genes in the humaz7 nrjb:wz+mc6 g2y )0*m+qiek nkf 4vn genome have already been mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one representation of a hk j+:6zw2kfv c7 *bzme4mn)+ygn0irqomologous 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 defiy:pc 9)ktsp8yh(m7rij/duo 6nition of linked genes?

  The diagram shows a karv5ukp:xo9 e. iyogram of a brown male rat (Rattus norvegicus). Which arro .u5opkei 9xv:w is pointing to a pair of autosomes?

  Mendel observed that there are two possible variations of flower colourz9ifr8ii8wyp 5q t*g: p/zf i, in pea plants, purple and white. After a genetic cross, the ratio of plants with purple flowers to white flowers is 1:1. What were the genotypf5y8: fq *p zigrz,pii/9 itw8es of the parents?

  The graph shows the frequency of birth weigx n +btxf.ig94ht of children born in London in 1991+4fb9gnix. tx.

  Which of these traits is an example of continuous variation /a9+oz(zpoa . kzmh-n?

  Which row correctly describes diploid and haploid cells in humanxhmju./ht,r q;h,31rgo g.s cs?

  The following table shows the diploid chromosome number of a range of speci m:fk/,lu*iwacc pnx96 :awm s* (iup,es.

Which of these statements is correct?

  Sickle cell anaemia is 4 kl.yz5 h4jqhhue7l18jds p+caused by a recessive 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 wie c;w/xm (j95lfttq*:g urtv66i, scuth blood type O. What are the possible genotypes of the biologic9;u(q6w6tr c xv gtclu/j,ifsm 5e :*tal father?

  Which row shows the correct annotati j7l:us7j+e kd ;.rnoson of the alleles for blood groups?

  Which of these statements are true f3 qd* tjs4e,+5ul3 ljt sy0p,avs*o08 cvycqror 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 incidence of sicr-2pjh1g 7rrlkle cell anaemia and the spread of malaria across -grhp72lr1j rthe continent of Africa.


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), fur colour is dej3nt3*7j,b: okb- tobear k2p termined by a number of genes. Brown colour (B) i-3t * jr3kaoj:t,bbnep7o2bk s 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 an6src :gw(cj;vn vxx 2f* ro)*ed unlinked genes.

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

Sickle cell anaemia is cau( n+/+3usfahfcp osb 0sed 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 shows a cross between a male cat that is nfqi z 3d6p:p mr4+ef1v9ag0xhomozygous for brown, long ha9:ivq f1rpnd03 xmp4 a6+fegz ir and a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele fo7xnm3 )xvj+jd+5uo w(yaa *vr r diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) is dominant over short yxjvx ndoaa3 *m)rw+ v7+ j5u(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 short hai3i.gm -6njl+ jcce(jy r (l), and curly hair (C) is dominant to sm gn.jjl-i3 y(cc+ej6 traight 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 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 tt+ d o2mepl *dpsc6e, n*vn1:phe inheritance of the condition shown in the pedigree chart below? 62,e otnn1l*pm *d: cvdp pse+

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

  Which of these statements abou)jzw: c 0743tk1rx3zl xcsjay t genetic 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 traits can show a normalfl,r7qvl/2 xda2tn8 ti9 x+rx 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 theh(4- k0g0rn tru e;bek disorder shown in the pedigree chart is X-linked recessive and not autosomal recessiveke r4gb e0n-u(rkt0h; ?

  Different species of living organisms he yz/:oi j 9,pv5jotbgl/qt,/ ave different numbers of genes characteristic to them. The table shows the estimated number of genes for jo/ ,:95zptqgiel/j,bo y t/v five species.
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, including flower colour. jsm pq 6)6ft9mo7(sqjIf the pea plants Mendel was studying can only be white or purple and follow the rules of Mendelian genetics, which of these statements was 6m q oqst9j)j6pm7(sfcorrect?

  A biological male with hemophztd11 jauhqzhuh.hg a*9 tp*1 c8+q v7ilia and a biological female without hemophilia have a daughter without hemophilia. What are the possible genot ca uhta *h7zt 9v+j*uz ghd.qqh8p111ypes of the daughter?

  A dihybrid cross was carried out between two sunflower plants (Helia61jowi 9 6p f9-hfrejl3s m8lynthus annuus) to39p9f6 r 6lleh ifjymsojw-81 see if the genes for seed number and seed shape are linked. The critical value for 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.uw9v v,d8ryr can have a child with bloo,r.vrd9 wyuv 8d type O.

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

3.Explain the role of inheritance in genetic diseases.