A man and a woman have a daughter a/ml)plc xe74and a son. Their daughter has normal vision, but their son is colourblind. Which one of these genota 4p)c lml/x7eypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somafah;eva/:.idl xe4 ,gtic cell in a human male?

  There are two alleles for flower colour in snapdragons. However, the resulh p7 zwx q(o91yb v /wh4uanxp8(-hb,vbb 78jmt of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red, white and pink flowers. Whixbppbh w 47a(vm9y8/7ubx h1h,-w( bzn jo8qvch is the most likely explanation for this observation?

  Which keyword is matched to the correc thq,h6tw+ a(bv0.i bct definition?

  Which of these statementsru9h 6co76q by is a correct definition for a gene?

  The diagram shows a pair of homologous chromosomes. n;bnp jelt)5-

How many loci are shown?

  Two individuals, heterozygous for a specific trait, werel6 4kqau.z70h87mr q(fkxgvo crossed in an experiment. Which row shows the exa l.h kq6 m8g477ukrvx(oqz0f pected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the a4f,ccqy o lb( mn-(6nogouti allele causes individual hairs to have a banded pattern. Theonlnbc( f qo,64-(mcy non-agouti allele causes hairs 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 plantsjv;p gpq.7v,b 0uexv79e f4o3 j j*aoq was either round or wrinkled. The results of an experimental cross yielded 315 offspringfxb evq 7 aepqj;gj79p jvu3o,.0ov* 4 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 chromosomes. Hox qbi46k0cl46z w-:thcy l5giw many chromih l bxkc-65lzw4q46yi c:gt0 osomes are in a fertilised oocyte of a fruit fly?

  When does the random orientation of homologous chromosswiozpgs3w( w9f ,a5 ,ome pairs occur?

The majority of the genes in the human genome have already beewau)axn*4:o ,qr7i o+ s *ldc6zqqub4n mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one representation of a homologous pair of chromosomequx7*z+n:oi*6ad)scwa,r uqql4 o4 b s.

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 linkts; s :7adipl/j,:m umed genes?

  The diagram shows a karyogram of a brown male rat (Ratt*2/ k alqske)pus norvegicus). Which arrow is pointing to a pair of plek/ kq2 *)saautosomes?

  Mendel observed that there are two possible variations of flod+1hwagak:b1ol -8 s,+ fk 9mme oa3qqwer colour in pea plants, purple and white. After a genetiq 8afmb1ow d,:he 3-ksoaglkq a9m++1c 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 born in London ing2od0p6 z nv.2q5xko i 1991 gk0d 6qvio2x o.z2n5p.

  Which of these traits is an example ofisn,ef+ugko r8 )ob9vum 8 e-9 continuous variation?

  Which row correctly describes diploid andf th 3nq*o .9l6halo7d haploid cells in humans?

  The following table shows the diploid chromosotd)lzuk8w + 7ime number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a re x+6ywe1 qdsx3cessive 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 witd fln4-p9;y 89 nwtgxvh blood type O. What are the possible genotf; nnp9-l4vy tw9x8gd ypes of the biological father?

  Which row shows the corre.r+ l,w/esooa;p um;yyj g5k; ct annotation of the alleles for blood groups?

  Which of these statements are true for allauordq)c1705: nz hfmm uaf23eles?
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,badto: +wj +dzh 55yllq hqz-j -ok7* the spread of malaria across the continent of Afoqdh-a+q5:bz wy7oh,t-d*+5 jjlz lk rica.


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 determined by a nu:ijsvum wo., 8mber of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) colouruo8sv.i:, m wj (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 geneu a00ztw1y ,xes.

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

Sickle cell anaemia is caused by the allele Hbmi 1* .t.vildnlhd3s ,c hk9e($^S$ . 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 cror5z azc-q)x*d/jwb8 ef5w*qo ss between a male cat that is homozygous for brown, long hair and a female cat that has black, short8w qd * xj/zaeqw*)5z o5cfbr- hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum 7gr384f1vs7hhhgmj/+ o-pe td - cujmsz,w * dofficinale), the allele for diamond-shaped seeds (D) is dominant over oval-shapedj h8vo+gemd17rtz4sw7c/3um -p j f ,d*-hsgh 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), long hair 2vqso;x* t 4;fddnsq8vu cb /9(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 c2q 8 4c 9xuvvt;bdsfo/;s *qndhi-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 inheritance of txwmaa3w31k ,vdnv9hf .c+ki +he condition shown in the pedigree chartkawxic9n,v1a3dh+ .f wkm v+ 3 below?

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

  Which of these statements about genetic disorders i.6d8a* abm dmgs/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 distributio.2h9xvkuv2;ebk 2k jz n.

2.Outline the differences and similarities between homologous chromosomes.

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

  What suggests that the inheszzpy n8lc9,g8tq ,mb0 9ml4kritance of the disorder shown in the pedigree chart is X-linked recessive and not autos q4,t0sz,znygm l p98bm89cklomal recessive?

  Different species of living organisms have diu pri6.qtig8 f)m;, m(avdrm,fferent numbers of genes characteristic to them. The table shows the estimated number of genes for five species. .)i8rmr, ,uqm( f6;gpt dm avi
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, includi 6-wx/;o .;+m-o 2etbdmm1 rujwzgsusng flower colour. If the pea plants Mendel was studying can only be white or purple and follow the rules of Mendelian genejo/swo.s ug16+m- -2mbw;t; u dmezxr tics, which of these statements was correct?

  A biological male with hemophilia and a biological female withosq.xt :e,i 7,yw/h malut hemophilia have a daughter without hemophilia. What are the p t, ,q/isw7:mhy.ea xlossible genotypes of the daughter?

  A dihybrid cross was carrm-dh j w.401oamc.qgn ygzu-1ied out between two sunflower plants (Helianthus annuus) to see if the genes for seed nz0ong11 .4ga mqwd-- hu.jycmumber 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 a- 4 tmhmvak :ie;57n,gcc/bob nd blood type B can have a child with bloo :mc/bv4 tg;e,5i om-na7ckbhd type O.

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

3.Explain the role of inheritance in genetic diseases.