A man and a woman have a daughter and a son. Their daughter has noo.,b):tr -mb gpgxan1rmal vision, but their son is colourblind. Which one of these genotypes could be correct for .pot-rbb1,anxmg g):the biological mother?

  Which diagram shows the sex chromosomu3j.m/ed+j yn2l v ql7es of a somatic cell in a human male?

  There are two alleles for flower coa, 7j/moc v-1s smji-nlour in snapdragons. However, the result of a cross between two heterozygous plants yielded oc - a-sovi ,/mj1smj7nffspring with three different observed phenotypes, red, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is match8 jr 2a/b js,e2vth7oved to the correct definition?

  Which of these statements is a correct definition 4h76 jdc (5emhcq;-2un/e log( swljufor a gene?

  The diagram shows a pair of homologmb m(fkf4c.0g3p/s s lous chromosomes.

How many loci are shown?

  Two individuals, heter:ihmraq,.nw gr736ohb81lnvlm i45 s ) o esw:ozygous for a specific trait, were crossed in an experiment. Which row shows the expectehi on4s 13l,b5)grlm6a s7:8v.oe iwnqwm:hr d phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti allele causes indiv(h)efgh lrxh* 09 x-npidual hairs to have a banded pattern. The non-agouti allele can *-9p)g flhxxe0 hhr(uses 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 indiv ob9 /foro(we4ofj76kh yj*jv/spz,5idual pea plants was either round or wrinkled. The results of an experimental cross yielded 315 offsyzjo /j4o7kfpb( 6 j/5weoo*s,fv h9rpring 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 (st vnc; fek6f zc it363oz,h:4Drosophila melanogaster) have 8 chromosomes. How many chromosomes are in a fertilised oocyte of a f k6z v, 64czhte3;o3:cfnistfruit fly?

  When does the random orient fu/8zepshxc4 ( v-i 5ir0l)nlation of homologous chromosome pairs occur?

The majority of the genes in the human genome have already been mappedhhg.n.zqqw /* 4am/ 1y ,vi(xkzyq6 mk, meaning the exacgy/vkzi4/w, .xm.1h (qh z*6mq kn ayqt locations of the genes on chromosomes 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,e8(*3ljv 6lfutzz/ t jtl9ve og,p 9y definition of linked genes?

  The diagram shows a karyogy6ecp14b3 kcnram of a brown male rat (Rattus norvegicus). Which arrow i3pn c ey16kc4bs pointing to a pair of autosomes?

  Mendel observed that there are two c3x.7y rflg1m possible variations of flower colour in pea plants, purple and white. After a genetic cross, the ratio of plants with purple flo17r lx.3mgyc fwers to white flowers is 1:1. What were the genotypes of the parents?

  The graph shows the frequency of bo) , cn0q n-(mixujqq*irth weight of children born in London in 1991xm*qqi -,c)0o(nu qjn.

  Which of these traits is an :am(phs9eqbv8 yt+3d example of continuous variation?

  Which row correctly describ l4lrai8xgbzf:t,/r- es diploid and haploid cells in humans?

  The following table shows the diploid chromos v;wx+ia8mz /k2 ll3lzome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive allu*y xgjo;ads:6.r r9y ele (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 haox(i.ba( .u 74mm0,otnhar vud a child with blood type O. What are the possible genotypes of th b,m0ua m.(i4oxu7atrnov.h(e biological father?

  Which row shows the correct annotation o*y 3+qev+)qv vmj ()i: igefkef the alleles for blood groups?

  Which of these statements are tru-/jjt 3m wz7xge for 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 oi(y4p*ts8 hvhhaq 6brmg 9q+/ f sickle cell anaemia and the spread of malaria across the continent of Africa*y q+q(htm g/h 4sha86v bri9p.


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 det :,rw,:tpj/sh+/ ocomqrhj/ d ermined by a number of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) wo: hrr,psdq +/ h//j,jt:com 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 genes.7rtq8uc+:s cie.hd:e

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

Sickle cell anaemia is caused by the allele Hb lvq ykhevnn)r3*9 ;j-$^S$ . 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 iy4ox9 2zk0+fxw q4xs ss homozygous for brown, long hair and a female cat that has black, short hozks q9w x4xy fx2s04+air.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale)wjkj cuww oit::89i8q 4t9pk7 , the allele for diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) is dominant over sho4:totw uk w99w qiipkj:8cj 78rt 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 hair (k1dhqjrzf ys985 ;a4o nyh27zl), 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 carrie; 8ayjnh7 2yfzo 9zh4q ksr51dd 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 inheritance2(swug5iz31l 9 6vc1 rkk vdxnlv1y(p of the condition shown in the pedigree chart belowvl rvkcg(1us3zv y6nx 15 i912( wplkd?

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

  Which of these statements about genetic disorders is/ar9- aug4h8ma kye 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 z p0ua ha o.+bd*.bh1 p:sbh*fcan 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 di ox4j g yqm43o0k7(s2t j3q h0ug hbuouxc07l)sorder shown in the pedigree chart is X-linked recessive and not autoso xq o 0c4lgty3j2xu 74b0 o7ugs3km(oq)j0uhhmal recessive?

  Different species of living organisms have different numbers of genes charactzd 6-lp-evdg 4p4 s2wmeristic to them. The table shows the estimated number of genes for five spec-dpe -pmgswv42d 6l4z ies.
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 b6 g8ex f lyv1a+3ez6nplants, including flower colour. If the pea plants Mendel was studying can ola ygzx16 3+ebf8ev6n nly be white or purple and follow the rules of Mendelian genetics, which of these statements was correct?

  A biological male with hemophilia and a7,oyv *exp8rfmx r68o ;u9u e,b)fi kt biological female without hemophilia have a daughter without hemophilia. What are the possible geno ye9tr6fru;b,7 m f o*xev oi8u8,)pxktypes of the daughter?

  A dihybrid cross was carried out between twoy5vim6eut;ks5 w37 hb sunflower plants (Helianthus annuus) to see if the genes for seew6b; 3yhks um5v5 iet7d 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 can have a child wxre*cpg-w9 pc1xz *0eith blood type O.e*9rxwe0pc *x zcp1 -g

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

3.Explain the role of inheritance in genetic diseases.