A man and a woman have a daughter and a son. Thei9ot,:a nivoo(6 :woi,/-p2 un wxmtl br daughter has normal vision, but their son is colourblind. Which one of thebwlov:otu(9i/:twma ox,n o i 2, 6-npse genotypes could be correct for the biological mother?

  Which diagram shows 0jaczhem+ w-(the sex chromosomes of a somatic cell in a human male?

  There are two alleles for flower colour in snapdragons. Hoiw)a g0s46rlf.wf gdb/a ni+1aunw7: :,oezwwever, the result of a cross between two heterofuww d)ano0f::n gb, 7 6/.1rz+ils4 ewawagizygous plants yielded offspring with three different observed phenotypes, red, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matchb7m);o*q vymo ed to the correct definition?

  Which of these statements is a correct definition f8 dq*kg.mk1w kor a gene?

  The diagram shows a pair of homologous chroq 7 0z :8( jvnqy5ebf+hvyv92 rnff7bi3ohk r,mosomes.

How many loci are shown?

  Two individuals, heterozygous for a speiu /u aa ()oercexf0*n,dts)v(a 8b9scific trait, were crossed in an experiment. Which row shows the expected phenotypic ut/ 9(e(n, u*adf eas x)bov)c80asirratios of the offspring resulting from this cross?

  In some animals, the agouti fev+ wd*-txmg; n5:bx68 catb allele causes individual hairs to have a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who a: wxbf;x5d -+b *gntteam6c8 vre 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 je)op y3-87v 7gklc mbeither round or w-3b7vlm) jc8p ky7og erinkled. 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 (c10 ctf 2gpnu.Drosophila melanogaster) have 8 chromosomes. How many chromosomes are in a fertilist f2.ncgu1 0cped oocyte of a fruit fly?

  When does the random orientation of homologous9of87hcy zs7m chromosome pairs occur?

The majority of the genes in the human genome have already been maf:8 e48v3jd9vai kro npped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one representation of a homologous pai ao:k84ejiv vndf 38r9r 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 defini:quc1ukspaawf u 4v+k*;ce /k zi4n 9)tion of linked genes?

  The diagram shows a karyogram of a browl plr0**dy n8dn male rat (Rattus norvegicus). Which arrow**nlr8dp ldy0 is pointing to a pair of autosomes?

  Mendel observed that there are two possible variations of flower col sq5n;c8eh me:our in pea plants, purple and white. After a genetic cross, the ratio of plants with purple flowers to white flowers is 1:1. What e :c58 mqh;senwere the genotypes of the parents?

  The graph shows the frequency of birth weight of children born in Londo9pq h-ddc h ,gxny*s9a0g .-byn in 1991bgydqs9gy 0a.dhnxhcp-*-, 9.

  Which of these traits is an example of cont( uayd9q,8- iwypy s3durd +-linuous variation?

  Which row correctly describes diploid and haploid cells in humdi0 tb*m+tvgx9jobxt+6 09ot ans?

  The following table shows the diploid chromosome num vkgz+yyq mxw:4/*a0 qber of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caumvm- oem2+ -obk9s rq4v2x6umsed 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 5ce,vzb/+i0ffv+o q b with blood type A had a child with blood type O. What are the possible ge/o+5c ie0, vvq+bbf zfnotypes of the biological father?

  Which row shows the correct annotation of the alleles for blooagmu 5hye/lk)gjz3ze , .-jn)mq8:)p,p kouid groups?

  Which of these statements are true)g)ga 8bg3njvr l -mc* 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 anaemia and the spread ofe z(utt8tq t,8 malaria across the con,tetz8t(t q8utinent 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 is determined by a number odc0wwdkb,/, e nl .mb;f genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (t0, n d.wbew;l/kb,cmd wo 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 linkezz53w y t3sy,w7xg bb/d and unlinked genes.

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

Sickle cell anaemia is caused by the a.+b .d.dtfisn)w:o bpllele 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 hom9pwt;hk gxt, -ozygous for brown, long hair and a female cat that has black, short hair.h; wt- k,xgt9p


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum ofzwlaa ,4 8-ydt2,)uebt8m dauficinale), the allele for diamond-shaped seeds (D) is dominant over oval-shew t aa-b 8u 8tyml,d,)zua2d4aped 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 sho 7g7w+spt2 z v5qqp3c zyr0(rort hair (l), and curly hair (C) is dominant to straight hair (c). A test cross was carried out between male heterozy52pq tv7zz3y0r(g7pcsq +row gous long, curly-haired guinea pigs 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 in the(ke5*iyj6m6yf ry. ms pedigree chart b y5k6(r6 eji mm*.ysfyelow?

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

  Which of these statements about genetic disorders is/are cor)i ojd:d bggxqczw8e1u*m4-s5iir (; rect?

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 t c.mdx njzrv,)ug r5,/raits 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 j3r1bj) u9tz)n d vc,sin the pedigree chart is X-linked recessive and not autosomal r1,snc tv z)9u rbd3jj)ecessive?

  Different species of living organisms have-0q h mg,kv+7p (7s dzzvyam)u different numbers of genes characteristic to them. The table shows the estimated nu+ m7 vs ( mzgvz)pkyu,dah7-0qmber 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)2-gegmjlk n*0olkxsky r6 2pksv((;)m 4tse ng flower colour. If the pea pn2y(e4gse0s);-kkt pol j (*gx k2km rmsvl)6 lants 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 hemophilia and a biological female without h 0znr6r o7, 3piybz wjc/kl 56fvzf60hemophilia have a 03icwr,f7/zr y65 nj0 zphl b f6o6kvzdaughter without hemophilia. What are the possible genotypes of the daughter?

  A dihybrid cross was carried out between twz alk0/0sv a9peb0u 0xo 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 taz0pev 0ul9ab0sk /0 xhe chi-squared test was 10.05; what does this indicate?

1.Explain how parents with blood t);wwd wp5*me df a7jpt7l( s/iype A and blood type B can have a child with blood dj 7lsetm7p;dpw5wfi/w( )* atype O.

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

3.Explain the role of inheritance in genetic diseases.