A man and a woman have a daughter ac lc o7/7 dq5js4qo6hsnd a son. Their daughter has normal vision, but their son is col/4hc6 7jsso5o7c lqqdourblind. Which one of these genotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic cell in a ,2ihe9x5 ncx igp) +bnhuman male?

  There are two alleles for flower colour in snapdragons. Howeo, mf:(evy/la ver, the result of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, redeyml ,oa fv(/:, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to the correct d; m)g(hv. x9ww+fh1fv3 o aog-zhd6j iefinition?

  Which of these statementwhp :2xvpb-x we4 0m(xy;7wwv s is a correct definition for a gene?

  The diagram shows a pair of hofh m:hu7;p* mtmologous chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were crossed in an exper * )-khnzqif6 xmlf25wiment. Which row shows the expect 2 k)fzhx6i5nq fm-w*led phenotypic ratios of the offspring resulting from this cross?

  In some animals, the ag.qc oqy:;ow(gouti allele causes individual hairs to have a banded pattern. The non-agouti allele causes hairs to be a single co. cyq (w:oo;gqlour. 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 plants was ephcqd*3 d ub*w.rx o25ither round or wrinkled. The results of an experimental cross yielded cpu wx.*qr*5ob3hd 2d 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 (Dro iew 4r,i3taf ner0)k npjvd;mq)/e0* sophila melanogaster) have 8 chromosomes. How many chromosomes are in a fertilised oocyte of neft3m arqe/ )epdir)0, ik*v 4n0;jw a fruit fly?

  When does the random orientation of homoloz.. zn6gxw 6i bfw:+mpgous chromosome pairs occur?

The majority of the genes in the humande4hv18xn ql a7/)lw6zbaem8 genome have already been mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one representation 8w8bd1xlqhnem4aa6ev z7/ )l 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 d dm oe/mq;x vw4dk+e:s 8b(d-aefinition of linked genes?

  The diagram shows a karyogram of a brown male rat (Rattus norvegicus). Which ar zc0hse(ush)f5w.)8 eqq 3epdrow is pointing to a pair zsh0 3w)8qpcfde uee(5)qh s.of autosomes?

  Mendel observed that there are two1 .oyzr1v ,khi possible 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. Wohi1krzy. , v1hat were the genotypes of the parents?

  The graph shows the frequency of birth wei +tcu.a kr8ba/ght of children born in London in 1991. ka/8.bc+r au t

  Which of these traits is an example i3je5yik ,e co4y ny2,of continuous variation?

  Which row correctly describes diploid and haploid cells in hum43 nbtzd8 pzoy:nw99 oans?

  The following table shows the diploit i-tn 5nn6/l)tlytx+ d chromosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is cinm3 p c)t)(wv8bwa7 eaused 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 z gukzq /dwghj7 ,nmmo4 :u ra1x++(b:type A had a child with blood type O. What are the po, kmn/z(gquwoj1:b+ah r+m47g:z dxussible genotypes of the biological father?

  Which row shows the corr 5cf+50:s lflqtk(0k*brgdkm ect annotation of the alleles for blood groups?

  Which of these statements arem(l okxzh f)wo17vj5; true 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 of sickler,zu5 bxirie5;o28k n cell anaemia and the spread of malaria across the co;ixbunk ,oz258rr5 i entinent 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 przewalsf9;yyg gmttc )o4)3 bdt *9ljolg,0ulkii), fur colour is determined by a number of genes. Brown colour (B) is dominant to d,o*g9)3l t;ltjybo4f0gm lt) y9 cgusandy 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 linkea f6 5c5es0zvoiv6y d.d and unlinked genes.

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

Sickle cell anaemia is caused (j ysb* 5c8g9/uhljcxr l* zls.h0c,lby 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 thab; ohfq/esp4 mkfzooo m29604t is homozygous for brown, long hair and a female cat that has black, short hairo9f;mz4k2 qbo6oph s4mf /0 eo.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele fu6ldl gl;.jzh+5 eod 3or diamond-shaped seeds (D) is dominant over oval-shapedlohzg5 ;udl d3l.6 ej+ 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 (L) is dominant to short h-5td2hse: yergm:50: d iyqzhair (l), and curly hair (C) is dominant to straight hair (c). A test cross was carried out between male heterozygous long, curly-haired guinea p0 5 :g dm5i yyeehrh-zq:std:2igs 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 inheritance of the condition shown -6 vpzq/.y 1w5yp hcwvin the pedigree chart.p zh1q6 y ww5p/vyv-c below?

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

  Which of these statements about genetic disorderixh 1v bph.s4r(8zy9f s 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 ca5v lnmj 2*9kapop,b3. iq 8yd g1xms4qn 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 thexr2aab9 hfp 83h jq7)z)lvyj:mf5/ ld inheritance of the disorder shown in the pedigree chart is X-linked recessive and jhy5)l fjxrma) fa29vhdlzp3 b :8/7qnot autosomal recessive?

  Different species of living organisms have different number3q 2 tnv*.k.n 6qkgxyks of genes characteristic to them. The table shows tk 3nqxqy *kkg2v6.. nthe 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, incqut04b* :: 8jjqzis77z 9w t6wj or5(xyp fmiiluding flower colour. If the pea plants Mendel was studying can only be white or purple and follow the rules of Mendelian genetics, which of 5 q *s6:fbpwo8i(70ur9:x7mtzjytqiw i 4jzjthese statements was correct?

  A biological male with hemophilia and a biological , jba;nn /. -sde/e1pvk l)wahfemale without hemophilia have a daughter without hemophilia. Whatd .lnwajns1 he-e,/abpk) /v; are the possible genotypes of the daughter?

  A dihybrid cross was carried out between two sunf pgro)c/ *d.jmlower plants (Helianthus annuus) to see if the genes for seed number and seed shape are linked. The critical value for the chi-squared test at the 0.05 significance level was 7.82. The calc dmcg/prj. *o)ulated value for the chi-squared test was 10.05; what does this indicate?

1.Explain how parents wf) bhya2uij ak:i ( r+6g-fq:lith blood type A and blood type B can have a child with blorb6i(igyl: : hajuafk2 +f-)qod type O.

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

3.Explain the role of inheritance in genetic diseases.