A man and a woman have a daughter and a son. Their daughter has normal atvqjd gpz)8*erizf9jzu-4u)ts /2, vision, but their son is colourblind. Which one of these genotypes could be correct-rp9gstzt/z8 d2vq)u j)f4jz,iea u* for the biological mother?

  Which diagram shows thez- *rsiutt 3o- sex chromosomes of a somatic cell in a human male?

  There are two alleles for flower colour in snapdragons.y/hu28sfa0 boci h 7-n 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 8c a-fhsn02hy7b iuo/ likely explanation for this observation?

  Which keyword is matched to the correct definiti0i7t3w6yti s6bp fdb 0on?

  Which of these statements is a correct definition f)u/wphx skdwrm4u;i7whkg *47b p1 8 hor a gene?

  The diagram shows a pair of homologk jj1o a-.3nqoous chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were crossed in an experimeu0qn02i p4ha0t 6 0ymbxl.gndnt. Which row shows the expected phenoun6dxi00b0gmhpt yl24 .qan0typic ratios of the offspring resulting from this cross?

  In some animals, the agouti allele c86buuy3ysw d0:2j y feauses individual hairs to have a banded pattern. The non-agouti allele causes hairs to be a single colour. I0yb6uufd:wy e32s yj8 ndividuals 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 indivl (f*q0uif1x yidual pea plants was either round or wrinkled. The results of an experimental cross yielded 315 offspring with round seedq(*u 0l1fifyxs 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 me3fcqxetbb7*q/u ,u m2lanogaster) have 8 chromosomes. How many chromosomes are in a fertiu3 /t*bce,qb 7m2qxfulised oocyte of a fruit fly?

  When does the random orientation of homologous chromosome ps- t goi,gl./3jgamv :airs occur?

The majority of the genes i39//eunlp g y3smuj2 u8q2wpin the human genome have already been mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shou8g p32nuy3/2mqp/el uw9 sijws 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 d7j; 5z y+i,ovddk4z zqefinition of linked genes?

  The diagram shows a karyogram of a brown male rat (Rattusv. 9xnqcd -/) ww* ,wvuz2b)xpsindd 5 norvegicus). Which arrow is pointing to a pair of autoso5)vw 9/dnx vc d ),p*izxd.wb wsn-u2qmes?

  Mendel observed that theny grkmp;m 72:pp0gq n;3b4y rre are two possible variations of flower colour in pea plants, purple and whiy;7 :0nbg3k;rgn pr2 4pmyqm pte. After a genetic 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 borrnwrbc botm6m ykut)(41gk9)1a,zg6 n in London in 1991r)bc9k yn)mgzuw1,okt tr( m 41 6ga6b.

  Which of these traits is an example of continuous variationlsh26 zul0 oo9 tws( (oits939 k+qdf dbab(,u?

  Which row correctly describes diploid and haploid cells in hw35kvpvs )dv 5umans?

  The following table sh t m-viljw(yv8(d3vkj3o; n lqk-8 6utows the diploid chromosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia isvv)d: ktoyy b5i,d32w caused 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 tyzgh1q+q 8ffbs a;(3qd0 ,ijzf pe A had a child with blood type O. What are the+qd qf bf1a h;sqiz fz,08jg(3 possible genotypes of the biological father?

  Which row shows the correct annotation of the allelesk(6b w:.o twjc for blood groups?

  Which of these statements20zpu sjp7- wck v(oa(i7 3pctjd2c,f are 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 sickle cell anp(m2g )bvku o90,i5 r pkje.mwaemia and the spread of malaria across tk,bv ip50k(2we .)omu9jgpm rhe 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 przewalsko r;b4as3k bw3ii), fur colour is determined by a number of genes. B4ow3as3;br kb rown 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 genx(k0p 6t6f*+v gv yf6xn-q4 h vl))5pxngvotxes.

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

Sickle cell anaemia is caused by the0 +nrbfrsst 56fc)c7,mxmr6 a 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 sho t m8/ce*ok4xn 01ma ;23hjq yek:dfgtws a cross between a male cat that is homozygous for brown, long hair and a female cat that has black, short hair. j ;ke3qfatxd8moy2tcknh1 mg /e* 0:4


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacunx6pibl*l 5lu)u g,apvq-6,d m officinale), the allele for diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for lon uvp, gl6 )ublxiplna*-5qd,6g 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)rezwi8 unv9r i369 7m:ds/kqm 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 carriem / 9niqv :simz9de3u7kr8rw6 d 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 in the pedigreeh -5rzy m:*,pc-end pd,nkgq- chart below n*-n dppz - k,:g,-y5mchdrqe?

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

  Which of these statements h3d002ol a6 :a+oznku,)f dquf) deyvabout genetic 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 l iwlp 1aqfs)gk ;6qpd56p)p5its 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 pedigree cha65nb;ixd, c+ jd,yvcwrt is X-linked recessive an6wbxjcnd,, id+vc ;5yd not autosomal recessive?

  Different species of lisjqxs0 r3 w p t4 lmaft1ing.p;y8*f*,ving organisms have different numbers of genes characteristic to them. The table shows the estimated number o rj40* qaw 8t,syxfmtf.1snp;g*3p ilf 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 sy ixxyqik+46g47 d(r, including flower colour. If the pea plants Mendel was studying can only be white or purple and follow the rules of My i qx+ 4syix4rdk(76gendelian genetics, which of these statements was correct?

  A biological male witht25q0mq bxaq5 hemophilia and a biological female without hemophilia have a daughter without hemophilia. What 5 tm0aqq5b2xqare the possible genotypes of the daughter?

  A dihybrid cross was carried out between t7l pa c1h2 y-:;rojlox;yq: cjwo sunflower plants (Helianthus annuus) to see if the genes for seed number and seed shape are linked. The cri yacjqp:7y ;rx:ol;j2-1oc lh tical 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 bl07e k1d deh0(xciyb3m8bmnp8ood type A and blood type B can have a child with blood typp3mm08xyee 08dc7in(kd bbh 1 e O.

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

3.Explain the role of inheritance in genetic diseases.