A man and a woman have a daughter alg/j8zersrx.;u f7,xq8 1 liand a son. Their daughter has normal vision, but their son is colourblind. Which one of these genotypes could be correct for e.xiqz71 g8fju/ r8a;ls,lrx the biological mother?

  Which diagram shows tf5py2 y:5 5 tdbms 7awunjl4;hhe sex chromosomes of a somatic cell in a human male?

  There are two alleles for flower colour in snapdragons. However, th )lkh 5hbj0a,t/tvbn9e 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 f,bb59)l tja0k vnhh/tor this observation?

  Which keyword is matche b1z1mi t8lx-l6pr1lx d to the correct definition?

  Which of these statements is a correct definitilt6 )j6b,cizg on for a gene?

  The diagram shows a pair of h,a e li7xtiw t3 +:6 g6.iyt5ytwv5ahaomologous chromosomes.

How many loci are shown?

  Two individuals, heterozygm-epa.wl.-n a7- qpu5 udiz8 pous for a specific trait, were crossed in an experiment. Which row shows the expected phenotypqi-.n u 8m7au-5.ppp -ade wlzic ratios of the offspring resulting from this cross?

  In some animals, the agouti allele causes individual hairs wsm0 j259v. vkxm(t+o9.ofv6bm t*uqgzuhe1 to have a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who are heteroz 9 (v v. qmfvs tw9tuo16z *+jghem2o5x.ubkm0ygous 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 plants w);wyn 2fwij(vs 3p:h uas either round or wrinkled. The results of an ) shn 32juwf:w(vy;pi 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 chromosomes. How mjt d:68v nwn5qany chromosomes ar q5 6wjvtn8nd:e in a fertilised oocyte of a fruit fly?

  When does the random orientation of homologous9plm v5;o 1tbn chromosome pairs occur?

The majority of the genes oc.n .s;ibtt9in the human genome have already been mapped, meaning the exact locations of the genes on chromos .stci;obn .9tomes 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 definition oxicj7(0 kp,xo5xsh *9l:j itof linked genes?

  The diagram shows a karyogram of a brown male rat (Ratgdn06misfuetv wc 8/p/.(4uitus norvegicus). Which arrow is0w/.nm8(/4fic suvut 6eip dg pointing to a pair of autosomes?

  Mendel observed that there are two possible variations of flower colour in pea jvdpddrn3+c8/ y fh 4l)fs 07qplants, 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 p+y dvclpfjh4/)f8s 37qdnr d0arents?

  The graph shows the frequency of birth weight of +uqeqrm,v:d v9 wly) 6children born in London in 1991e)lw:rv, +uvq6dq9 my.

  Which of these traits is an exf(oy ez te + :r oawras*251zexl*c/*eample of continuous variation?

  Which row correctly describes diploid and hiql lwm :9tj6s83qle5nal0 y6j*2et eaploid cells in humans?

  The following table shows the diploid chromosome number of a range of specivh) 4(zm/ms)zwh xi6ws,e za9es.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessiverx3e 9l54zll n 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 a1td, :k(vxgp o child with blood type O. What are the possible gep (xvkgd: o,t1notypes of the biological father?

  Which row shows the correct annotajztc)/sx9k5+fkunn4 fu se)os p /,b+tion of the alleles for blood groups?

  Which of these statements are true for alleles ;tsr4f ,9rgff?
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 anaemiwb dhj -1s11jva and the spread of malaria acroj jdh1sb1wv1- ss 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 (Equus przewalskii), fur vk:kdv01/sr*oxsx/ce7:2guif o; gf*et g -m colour is determined by a number of genes. Bro xov/g-f/* :omf e* dxirg:cs07g2 ute1k ks;vwn 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 gene - yvgp9ehl-0gs.

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

Sickle cell anaemia is caused by the allelyxyn vrt1wp:5a):a 0 be 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/ub no-q:gxfh vc., vm8tbq w594g1lr homozygous for brown, long hair and a female cat that has blg hqm9g w-qnbcfr/b1, vu: 85ovx4. ltack, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Tarax:,m von / +-+pnwgfgmdacum officinale), the allele for diamond-shaped seeds (D) is dominant over oval-shaped seedm w+d-fpg,mg+o/v:nn s (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 j7rn m:b/x:njcm3d hf4eo1 z,oxz/n - 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 and female short, straight-haired guinea pigs and a chi-squared test (χ2) was carried out on the offsprirb/ 3:zc,on-fj7o nx/e zj4mhndx 1m:ng.



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 ctpfz-ji. b;- uk:oe psewm.w6e0;.einheritance of the condition shown in the pedigree chart u-:eep6 .mz.fw bices;jo.k 0t-pew; below?

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

  Which of these statements about genetic dic3;yc3 ;hvykq sorders 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 distributiorf (zfg:cg*6 z;pe4vz n.

2.Outline the differences and similarities between homologous chromosomes.

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

  What suggests that the inheric wqb;7n;topa7xu l5iqt12 0 rtance of the disorder shown in the pedigree chart is X-linked reccoi; ax q0l7r1pu5 ;w7tq2tn bessive and not autosomal recessive?

  Different species of living organisms have different rsblcgjlh*/hl(w3v1npi2v f3u: rd(fm +z6 4numbers of genes characteristic to them. The table shows the estimated number o3rvd vj4r*shzcmu2l6 l:bfwfnp l1i( 3(h+/g f 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, incluoyu;y j5d3qf- ding flower colour. If the pea plants Mendel was stu-yu5y o3q;jfddying can only be white or purple and follow the rules of Mendelian genetics, which of these statements was correct?

  A biological male withc:knf4q5 i4wz hemophilia and a biological female without hemophilia have a daughter without hemophilia. What are the possible genotypes n4:ck zw5 qf4iof the daughter?

  A dihybrid cross was carried out between two sunflower plants (Helianthus annuusb,tu.xmih0i dvs 0c 5.) to see if the genes for seed number and seed shape are linked. The critical vav, bid hm xi.s00t5cu.lue 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 can have a child with b lj;t phdy46. c1 wed9s6ava7llooajh 46d1;wld6l vyp.t7e a sc9d type O.

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

3.Explain the role of inheritance in genetic diseases.