A man and a woman have a i ;ol 1gf x2ed:a)xqu a3v(g8adaughter and a son. Their daughter has normal vision, but their son is glagx 8x1oa:q v3f ) ae(;2udicolourblind. Which one of these genotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic cell in a human mm6h-12r cnppi7f )zc tale?

  There are two alleles for flower colour in snapdragovb9w al+opy5rl+ :aj2 yg/ 8lons. However, the result of a cross between two heterozygous plants yielded offspring with three different obserl2 jly++5valpoawr /ybog: 98ved phenotypes, red, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to the correct de2xtg iw( 29vrhfinition?

  Which of these statements is a correct definition for , j3 av)qfw7kn.kg t.ga gene?

  The diagram shows a pair of homolo*fmjptlf pyb1a icoml,4r ( 57rxt;1 5gous chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a spe o))4 ;njlgezw* wkuo zvy90,vcific trait, were crossed in an experiment. Which row show4g wk,wv;n)j0loz*9ez u y)ovs the expected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti allele causes individual hairs to havehsw y q,b(a mg(pqe512j/v s0e a banded pattern. The non-agouti allele ,1s gq02(m (/yjqb eesvwpa 5hcauses 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 individual pea plants wasm,2axvmt-r(r*flw lkf o5f . ; either round or wrinkled. The results of an experimental cross yielded 315 offspring with roun2mwrmar-vf*o; ft.,x5f(l kl d 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 (:: de-x xdybh3Drosophila melanogaster) have 8 chromosomes. How many chromosomes are in a fertiy3dbh:d e:x- xlised oocyte of a fruit fly?

  When does the random orientation 6(sxk) bp:ctnof homologous chromosome pairs occur?

The majority of the genes in the human gefeh+ - fes6ex9nome have already been mapped, meaning the exact locations of the genes on chromosomes are kff e+ee- 6shx9nown. 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 linked gr0wlj6i ij n7pz:2;hfjw8 fn .enes?

  The diagram shows a karyogram of a brown male rat4tapcvc*)tb1ux /cb: :ag9nt (Rattus norvegicus). Which arrow is poi/vx ) bab9nt*:tugcpac tc:41nting to a pair of autosomes?

  Mendel observed that there are twgz ;j 61kncfbgzw**2-ka no,wwo8h,ro 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. What were the genotypes of the parenro1g h6kja wz8*k-n;2z cfn, *gb, owwts?

  The graph shows the frequ+pc3btiu vymbrmt,-.exonf6 2 a6 t/7ency of birth weight of children born in London in 1991.p 3u+6t,7 to- 2nx.vmfecai tb yr6bm/

  Which of these traits is an example of continuous vari1(hj t e evxx-72v:upeo0hvg 5ation?

  Which row correctly describes diploid and haplb:rv8i;28w wt4: lij1ayulxw -3rfoq oid cells in humans?

  The following table shows the diploim7u/bq ( :tw17a. )8myttgsx -ufonkgd chromosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is jno3j(dhal:5 iml v52s.9 llt 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 type A ha97c htnoq8grm.hn : o-d a child with blood type O. What are the possible genotype .rq98-m:nt7nochoghs of the biological father?

  Which row shows the correct an063n6h) ajx,,n i lfdedj-xzdnotation of the alleles for blood groups?

  Which of these statementsaxdnahr:.37c6 nf 8nk 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 inci 05igo *399c /zn i9cp k;ttzbeyaau,wdence of sickle cell anaemia and the spread of malaria across the contg onpzi,u90wkic3caa9 5/e9bt * z; ytinent 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 colour, z(d,l;dtfeiek(pe/q- 5bl f is determined by a number of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) colour (P) is dominan (b,lf/le( d-zet,fe kqi5;pdt 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 u3d6 jziz 0j;t*7s xe6epwou/2kebt5 rnlinked genes.

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

Sickle cell anaemia is caused by th hv6ukz7xz6n ku0:+5b row 5lpe 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 h(eb 0 m/l2raihomozygous for brown, long hair anrhelbi(a0m 2 /d a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamond-shaped seeds (x(n7ll697evpts wivy 2;am(sD) is dominant over oval- ( aypsvsi lwen96(x7v7l t2m;shaped 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) if ru+u2bmv wgzp:2b*5s 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 ch*ug+:2 bwvzp urmb f52i-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 show xs(ep :z-)dagp8 naj(n in the pedigree chart bz 8p)a-px :njas( e(gdelow?

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

  Which of these statements abou.a,q*nn kf ly+/-;gsch i, e8du1thbet 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 ux (8nhga-9 w i4(uu: kfj/dx3;la zokshow 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 inheri6ichh f f-5uh5h r.w7ntance of the disorder shown in the pedigree chart is X-linked rechnh765 5fu-hwr. h ifcessive and not autosomal recessive?

  Different species of living organisms have different numbers of genes charactez, m 1n8:abkovdmwm-b5 .ghp8ristic to them. The tablwo z.m h ,8ab: n8mgdpv1km5b-e shows the 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, includi+yry6:/lioyr8p 8gol*u 7 h zvng flower colour. If the pea plants Menlr86iov:h8ry * o/l yuzg7p+ydel 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 hemophilia and w f+* q)tum0qvicl.vw0rm 3; 2r5vvd:vgrca) a biological female without hemophilia have a daughter without hemophilia. What are the possible genot lmgi)rwrv ) 0:c;c vmu 3t0qd2v .q+fvav5rw*ypes of the daughter?

  A dihybrid cross was carried o40kuhy 12g atmut between two sunflower 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 calculated value for the chi-squared test was 10.05; wut1 4hygk02mahat does this indicate?

1.Explain how parent4 kq1k) m/g gdrlnc-.gs with blood type A and blood type B can have a child with blood typm.rgnckdk41 - /qg gl)e O.

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

3.Explain the role of inheritance in genetic diseases.