A man and a woman have a daughter and a son. Their daughter has normal vitowu1 .bu k0u-sion, but their son is colourblind. Which one of these genotypes could t1o-bwuuu .0kbe correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic cell ilm8r:t+kb olu0f38xh pjr+nd 4 yx.-un a human male?

  There are two alleles fo+)4avlz4s ah.d prfr .r flower colour in snapdragons. However, the result of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red, white and pink flowers. Which is the most likely exp +hlfz4 .rs4 pav)r.dalanation for this observation?

  Which keyword is matched to the correct defin)6fsmt3zb :k1yic80) is u 9ip+ice wsition?

  Which of these statements is a l)-z niuip :(,(n 1mczmmdu7 qcorrect definition for a gene?

  The diagram shows a p.0 z5iqtibc y:air of homologous chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were4u vadp :5ch4wqa 5(6uazhpf ( crossed in an experiment. Which v q6 hw:(c5ud4zfa5ua4( h approw shows the expected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti allele causes individual hairs to have a bandi;ezg6y8lh gh+2u hu( ed pattern. The non-agouti allele causes hairs to be a single colour. Individuals wh gilhh2hy+ ;u(z ug6e8o 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 ip-80 crmrr6h6d :g yhv9r elibwz28c( n individual pea plants was either round or wrinkled. The resulti6(e-mg8c h8czh0bp r: l26rr9drywvs 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) havhxia3 dm2xyc e/0f9d 7e 8 chromosomes. How many chromosomes are in a fertilisd /mx3xfcdh0i 92 ye7aed oocyte of a fruit fly?

  When does the random orientation of homologous chr6bm-jqk ,3 ddx/,z ja.,fvwqys 1um/ 6 6ckkywomosome pairs occur?

The majority of the genes in the hfm90 6*idr,xokvp/ir uman genome have already been mapped, meaning the exact locations of the genes on chromosomes are known. The diagram belixr v dkim09,/6*r fpoow 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 6 hmqnl/d7b5t mnt6a0ion of linked genes?

  The diagram shows a karyfuoe/mopu ,a6w6 (mk+ogram of a brown male rat (Rattus norvegicus). Which arrow is pointin+/mkeo, w u fo6m(ua6pg to a pair of autosomes?

  Mendel observed that there are two possible variations of flopxfkcqx -( i9+wer colour in pea plants, purple andcfpi-q (xkx9+ white. After a genetic cross, the ratio of plants with purple flowers to white flowers is 1:1. What were the genotypes of the parents?

  The graph shows the frequency of birth weight of children zmeh+m*6ua z7p -3i *:occ bqwborn in London in 1991hipq :-*zec*736 aw c mzuo+mb.

  Which of these traits is an example ofh.5 )mffqsk -;axrkb*(k1xx a continuous variation?

  Which row correctly describes diploid and haploid cells in humans? r -uvzr zx,o. t/b-i4c

  The following table shows the zya(0lm hps+ 7diploid chromosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is9. c*br 8tu u7+(crwis)fffxs 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 with blfb*zxmf:9 e.p ood type O. What are the pe :.xmfz 9fpb*ossible genotypes of the biological father?

  Which row shows the corrad bv7liiladi636y+mc ,g:f/ ect annotation of the alleles for blood groups?

  Which of these statements are true for alleleb dhxp-2u4:p fs?
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 and the spread of malaria ac p-c3/ovqk; onross the continent of Africa. cpq3 -ko/;von


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 prze0 .k vtov *hju5tiu*0lwalskii), fur colour is determined by a number of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre ( ohjitkvvt 0u*u5.l*0two 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 ur41lx8gy8fy w ct z-, 12hs yksa3zkt0nlinked genes.

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

Sickle cell anaemia is caused by the allele Hlgsx .)ud r5nt-a2x 6 /ev)j/ osq+ozzb$^S$ . 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 /sbpt o ),apz0male cat that is homozygous for brown, long hair and a female cat that has ,)s0ba p /ztopblack, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Tarax*f2c8y;+ kawqx(adk ;6 axnuiacum officinale), the allele for diamond-shaped seeds (D) is domix * ;;+xidk62nya(cfak q8a wunant over oval-shaped seeds (d) and 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), j d;t4er8vb nrj.,s-if:x u j8long 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 n,88esiux tdjj-;vr:4.rfj b 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 the inh i1z4lyy42+6meo pf4erpv0w qeritance of the condition shown in the pedigree chart b241oz m+lypy60ewfvrepq 4 i4elow?

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

  Which of these statements9 q1fp(z b/0k0 4 no;d9pqa.mkewltcj about 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 normal distribu za a9iknw:2mp47ous1tion.

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 disord4 ya-:j8 7imjpd1jklver shown in the pedigree chart is m py j-1j4:jikvl8d7a X-linked recessive and not autosomal recessive?

  Different species of living organisms have different numbers of genes characterio8a; ghpo8(wyi l iz+2stic to them. The table shows the estimated numlhp;wi(2y8o+ gao zi8ber of genes for 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 colouk.kb7p (dv 4gax :-rrjr. If the pea plants Mep 7v:jakd(4gxrb rk .-ndel 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 u9ft sry6b k8xt/3q t/biological female without hemophilia have a daughter without hemophilia. Whax6u9qt k t8yr bs3/f/tt are the possible genotypes of the daughter?

  A dihybrid cross was carried out between two sunflower plantsox lppq d z+i+-88gr9mxs5b gwhp. jy04*i9 ub (Helianthus annuus) to see if the genes for seed number and seed shape are linked. The critical value for the chi-squared test at t p-r8ys hi98 pbb m lqjdx0g.9 *54opgx+iuzw+he 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 Asvw5 lvv2j(p:hyv(9u and blood type B can have a child with blood type O.2(vpv( h5svlwyu:j v9

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

3.Explain the role of inheritance in genetic diseases.