A man and a woman have a daughz.s hgt f7zfv:*ckiq 3mwt(:5ter and a son. Their daughter has normal vision, but their son is colourblind. Which one of these genotypes could be correct for tg i:vz(fkhczt3:5s tf.* mq7whe biological mother?

  Which diagram shows the sex chromosomes of a somatic cell in a human maletdgt6yrph.7pq: n,s ( ?

  There are two alleles for flower colour in snapdragot/u9u db +4gdf(mn1 icns. 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 most4 imbdu+ ut1dnf(9cg / likely explanation for this observation?

  Which keyword is matched to the co+anrm: e szc(3 * x2dgmsf8,rwrrect definition?

  Which of these statements is a correct definw:bw:n)p97bf) t8btprk ij u0ition for a gene?

  The diagram shows a pair of homologoub) nl j;qzmr- ts(y8aha9 19 cwuths11s chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were crossedbtn ,e-n/ :ktp in an experimen/e kbt-:nnp t,t. Which row shows the expected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti alle4v d kv cr6.zczop0*k6le causes individual hairs to have a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who are hetekrodzpv6c6zv 4. c0k*rozygous 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 96p:9k4nzbtq wi9ch35yc zws;pnde 2 shape in individual pea plants was either round or wri6ysn:z9w9z qt d32p9p5;h cwbckien4nkled. The results of an 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.pu:5.tpn h r2e How many chromosomes ahru .nt e:2pp5re in a fertilised oocyte of a fruit fly?

  When does the random orientation of homologous chromosome paihi-s*ap*v ee ;h:)w uzrs occur?

The majority of the genes insedygo j69 e/u0j5uuas /7( yf the human genome have already been mapped, meaning the exact locations of the u7 e(y6yofuua/09js g edj5 s/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 definition of liz) vzknk8g372f e/ :gzz ixis;nked genes?

  The diagram shows a karyaolfvci+2a(gfcp me q3 3p9m )9x v4bogf ;70bogram of a brown male rat (Rattus norvegicus). Which arrow is pointing to a ov c(pgem74fc32f3oxqpbf;0 a) mb9+vl9iag pair of autosomes?

  Mendel observed that there are two possible variations of flower con. dt sfq*b1aem93 /hv(3nnljlour in pea plants, purple and white. After va(tnj n9eqb3 dn1s3/ h l.mf*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.j 5iwnxr* 5en children born in London in 1991wenn. 5jx5*ir .

  Which of these traits isjp ot0b3(xq-6cov8vh an example of continuous variation?

  Which row correctly describes diploid and haploid cells in humanql.nut,yp r6 r )8s/ ,hogrs;bs?

  The following table shows the diploid chr.c(b7tj9tw+rz +eo bk :,pvycomosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is cq3 m :g, 4phyn;r;;pqo jltho6aused 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 withr38f3t lev+zv/0vz ii 6 p*ptt blood type A had a child with blood type O. What are the possible gelip6r/f v zve3piztt38t*+v0notypes of the biological father?

  Which row shows the correct annotation of the alleles for blood grotd7uk o/9ea9 mups?

  Which of these statements are tru f*pwbd 4;m4-qf ic,xlahkgb 9v 0pg14e 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 anae45 r0kq(x-q*c qh8s-sig vr ihmia and the spread of malaria across the continent of Afiiq5 h84xk hgssq0-r-( c vq*rrica.


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 colou;u/mr8h mvnzijx z-: 5r is determined by a number of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) colou-z8jvuzn;im :xmr/h 5r (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 gensd caxgb w.1(/es.

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

Sickle cell anaemia ist nl z8*jg*qqzx .l/;mody(:p caused by 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 that is homozyg0*bfz) mlnlo; n7( nsnous for brown, long hnbf7n0 lo (snm*lz; n)air and a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum offi7 o-v p9(ctmdycinale), the allele for diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) is dominant over short sep-o yc7(tmv 9deds (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 shor3 fw lr(*zw0zk w9h:wrt) rh9gt 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 carri: 3rg(t kwr*z0hhr wwf9w 9zl)ed 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 inoq9*v bnh3 *dr the pedigree chart belq vbr3*h9nd* oow?

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

  Which of these statementkc e/.lwart -8s about 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 traits can show a 2gw4hx4an)yd 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 pedigdjmsg,nx9sbm6yt5 lg ;1mw 75ree chart is X-linked recessive and not autm9ygmt67sm5nwx d,g;j5l1s b osomal recessive?

  Different species of living organismg-)jwk f 94jsgs have different numbers of genes characteristic to them. The table shows the estimj jwf4g 9k-s)gated 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, including flower cogaup dz.m ):ntszavh43.q) e*lour. If the 4)n*psa .uezdq ) ztg3 .a:vmhpea plants Mendel was studying can only be white or purple and follow the rules of Mendelian genetics, which of these statements was correct?

  A biological male with h40gy/m, xrdrd j z-*lzemophilia and a biological female without hemophilia have a daughter without hemophilia. What xldm z ydj0/gz,r -*4rare the possible genotypes of the daughter?

  A dihybrid cross was carricc*6af-j,zu na2 zi vu 7m6y8nkr k2:jed out between two sunflower plants (Helianthus annuus) to see if the genes for seed nuun a-8mv2c2z 6 f:jark,i7*nz6c jkuy mber 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 rfbl+ h3f )uxti)/3.b/ ji sagch-j :xA and blood type B can have a child with blood type +x 3a )b j l -j/bfh)uiirxt.:s/gfh3cO.

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

3.Explain the role of inheritance in genetic diseases.