A man and a woman have a daughter and a son. Their daughter has normal visio ot8xwin8fdp(hl m 80)n, but their so8(0 i8 hmt)8po nfldxwn is colourblind. Which one of these genotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic cely ;cc -ypht95ll in a human male?

  There are two alleles for flower colokajng-/n 443z a5pslvur 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 explanation for this o 4-aakzs3g4 5vnj/pnlbservation?

  Which keyword is matched to thu c1c p nbyertoh73(.ww84 v.we correct definition?

  Which of these statemen;mlko6d- t 1tyts is a correct definition for a gene?

  The diagram shows a pair of homologous chromosomes.:of yppdc)dm0a,6v m5

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were crossu67hs tba 0z8h xl7sq5ed in an experiment. 08h65xszst la7hb q 7uWhich row shows the expected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti allele causes individual ha7: lmfe z3m7:imuao :uxa+u:uirs to have a banded pattern. The non-agouti allele causes haioxa7u+ lmfi a:uuu: mm37ez:: rs 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 p3x1bo.2(o j::kddje n o)obgjnp :9 ncea plants was either round or wrinkled. The results of an experimental cross yieldb d:2coj9kon)1:og b ejp.(no3d : xjned 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 (Dru qc)c3-d*jk8m aik psmv3e; 9osophila melanogaster) have 8 chromosomes. How many chromosomes are in a fertili39 ja;pvki s uc38k-q*dmem)csed oocyte of a fruit fly?

  When does the random orientationvqcnx : b*6( sr/xq1w7tb kjb 5ra5,td 0gh;mh of homologous chromosome pairs occur?

The majority of the genes in the human genbzf2o0o* 1rrg ome have already been mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one representation of a homologous pair of chr 1 r*0zfgor2obomosomes.

1.Define locus.

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

3.Distinguish between gene, allele, and locus.

  Which is the correct definition of linked o20,s ycf0yewgenes?

  The diagram shows a karyogram of a brown male rat (Rattus norve3e g+sh9b f;h4luhxbt,0 t /pjgicus). Which arrow is pointing tx;4hf0/tblu3+ ,jb9t sphg eho a pair of autosomes?

  Mendel observed that there are two pos/tldd 24x; bmq( zvcy,sible variations of flower colour 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 genotypes of the pax4y,d tv ( qbm;zcdl2/rents?

  The graph shows the frequency of birth weight of children born in London in 1i8an)eh5gud 1 aq.9op h)g8py 991. p8an8u1 hyea9q )pghi.d5go )

  Which of these traits is an example of continuous variationx tgslz8o s9vm1c9 s:0?

  Which row correctly describes diploid and qzxbye (x :j./haploid cells in humans?

  The following table shows the diploid chromosome number of a range of species. mv: dfad- ;:bi

Which of these statements is correct?

  Sickle cell anaemia is caused by-gb cb+lxqab u*9o 5x( 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 chiof1p/6omyf . tld with blood type O. What are the possible genotyp ymp6of.1/f toes of the biological father?

  Which row shows the correct annotation of the alleles for bl.+ acsll:;8elrw8n2f7uo cj r ood groups?

  Which of these statements are true for alleles m3+l7tdus2m: sy( pfo?
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;uccy/ d mu;ee v )*dnm(g1pd1 of sickle cell anaemia and the spread of malaria across; ;myn u1v 1dmee /gp)(*ucddc the 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 (Equd1r o fmhj16/ mwcce(l9wcz)d5 z(:cpus przewalskii), fur colour is determined by a number of genes. Brown colour (B) is domierjfcpm)/wz hzc16 cd:o(cm9w 5l1 d(nant 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 unloqfb9;r p egvk; 0bgx)a ,u)j5inked genes.

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

Sickle cell anaemia is caused : viz8qbfh;- zby 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 homozydi e pz03q6( hgsr8x4vgous for brown, long hap xz d8q 340(e6rshigvir and a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinalc4ejl*cjwyf95 y7 i*x fo9 2 j6ieuh.ke), the allele for diamond-shaped seeds (D) is dominant over ove9cj2 ol .jfe5 *4yyfihwui*6c j7 xk9al-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 (Cavi78pvi5m o,t-ybcly d)a porcellus), 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 d,pyym)o87itcb- v 5land 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 inherita o(p9m)nbtofe uja07. r2rs1dnce of the condition shown in the pedigree chart below? 09oprrdnf7mt2 )(.oja1 e sub

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

  Which of these statements about g;uw vgmrl .byi5d,8p 4khaao6 -3i1ryenetic 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 tra -)p -tvyzf4uo ehnps3ge7 *p7its 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 pedigrbm7g ;7i j0wn i5fauy*h a+g-xee chart is X-linked recessive and not auhgb a j0+a7;umwy57-if ix* gntosomal recessive?

  Different species of livtka:p k5m(i g6rqj4r0nt .+nking organisms have different numbers of genes characteristickra:t .rt k(5npmi04kqg+ 6jn to them. The table shows the estimated number 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 colour. Iz2 /vf2hyj.w ac9z8h tg6div+f the pea plants Mendel was studying can only be white or purple and follow the rules of Mendelian genetics, which of thdi vj.h8 6z2a zgw+ft c9/y2hvese statements was correct?

  A biological male with hemophilia a tf2u7a yhnl+bycloqpx2l.j32u29u9md)v;and a biological female without hemophilia have a daughter without hemophilia. What ab ypq.v;ll7n2lm +u tu2a2 9)y39dochx u2afjre the possible genotypes of the daughter?

  A dihybrid cross was carried out between two sunflower plants (Helianthus ar2 o(v+xw5v,szlzzk gp1k 93 annuus) to see if the genes for seed number and seed shape are linked. The criticalg9kk zwozvzl(r sp,31xa25v+ 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 anc +smgbda, g;bnx)xm9,8se i)d blood type B can have a child with b9scxm; bxsan,mi) b) g+de g,8lood type O.

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

3.Explain the role of inheritance in genetic diseases.