A man and a woman have a daughter and a son. Their daughter has normal vision, bw l. 8dvqm)qo0ut their son is colourblind. Which one of these geno m.0)lwv8qd oqtypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a soml jy6 5s);xg 7djw4cfga.*dzbatic cell in a human male?

  There are two alleles for flower colour in snapdragons. Howev 9d/ t6wz-uq4kv,hvkosiu0f3 er, the result of a cross between two heterozygous plants yielded offspring with three different observed phenotypehutfs9 /iq- vz63okwduk0 v4, s, red, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to the correct definition0rv-phq0gs o) ?

  Which of these statements k dupmp )hu6e54ru+ iqv 92x86isa)swis a correct definition for a gene?

  The diagram shows a pair of hom *z x93 ippwzx/.d+9kpwvn4t*i fr-qlologous chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were crl zx4-vlzi:u -ossed in an experiment. Which row shows the expected phenotypic ratios of the offspring resulting from4il : xzv--zul this cross?

  In some animals, the agouti allele causes individual hairs to have a xmvyg.t 9n2v j;j)rzwd1 -vm7 banded pattern. The non-agouti allele causes hairs)xr 9dg-n2m1y .t;v7zjj mwv v 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 was either royn h6k*f+emtg2z3 mw .und or wrinkled. The results of an experimental cross yielded 315 offsprin*m3.f+2w yhegk6mn ztg 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 (Drosophilavi mn b.quvt313p3kr9 melanogaster) have 8 chromosomes. How many chromosomes are i33vq3tb.1pri9 m nuvkn a fertilised oocyte of a fruit fly?

  When does the random orientation of homologous chromosome pairs occur c uw)urrg;f4qboympv 226myr2 v) 0o/ic9qt 6?

The majority of the gsp7y /m,t97od)snre kenes in the human genome have already been mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one representation of a homologous pair odro7ktms 7sepn )9/y,f 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 ofo s-/ht :rn1xrr5 dnm. linked genes?

  The diagram shows a karyogram of a brown male rat (Rattus norvegicus). rhq n4kd7 sbx)w:g 1f24r;s(lgxj6rwWhich arrow is pointing to a pair of autosoxhs(d :w 1)xsrq 4glrj4r2n bfg6k7w;mes?

  Mendel observed that thergqlsxdx93 f)jygu: 2 6e are two possible variations of flower colour in pea plants, purple and wh6xg2 )3g :9x dflsujqyite. 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 c 4er-pzv5jc;jds g 6y9d0aua:hildren born in London in 1991. da zy6: rj054uv;sa-gecp 9 dj

  Which of these traits glh a b,qh3k7f7atta ),y ,aq+is an example of continuous variation?

  Which row correctly describes dipqts7duq,m5j r+; :ip tloid and haploid cells in humans?

  The following table shows the diploid chrob zbnq)4,7pm a:ls* romosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is cauar y4; fr;x2/(kuapxvc 5rn8i sed 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 3s-v oaty; 8iahad a child with blood type O. What are the possible genotypes of t-8a v3s;ityaohe biological father?

  Which row shows the correct annotation of the alleles for blood groups9k5jafu du*l+lu..ot y c mg()?

  Which of these statements are true for all z0ccg5wg70q oeles?
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/mr3d p:vl,yg l-b 8fq(x,akh of malaria across the contin(mfbpxr-ldv, 38ykah,l q g/:ent 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 przewm: n107dbpt34q qhg n4iu0xigalskii), fur colour is determined by a number of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) colour (P) is 4hquxibd7n0n 4i3mptg0 :q 1gdominant 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 unlinka2ni5hk3*: 2 g(vzyo crmg b/red genes.

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

Sickle cell anaemia is cac5o0nw xuq 6 9:rmu-knused 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 homvv5 7 ctjky4k:vtrx+r- ;; ty0za /cdyozygous for brown, long hair and a fem+avy cr;:/ ;t y0kz4kjr7c-5v xdvt ytale cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamond-shaped seeds (D) el5)yq)-o0 iqvj0vraa)- nwyis dominant over o-r0j oay-5 yv liaeq)wn)0)vqval-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) is dominant to short hab 6 ea*3f1fjmgir (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 carrie3*ef6fm ab1 jgd 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 inhv ; 7l xxesq4,kblz7(neritance of the condition shown in the pedigree chartlzqs 4;7 vkxenblx(,7 below?

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

  Which of these statements about genetic)z q*1kyp bu 9ux-zc(i 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 norkx-w akq*+q,f mal 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 showni 69a:atey(jk :c u5eu in the pedigree chart is X-linked recessive and not autosomal recessiv6:tue (ayea:j9uck5i e?

  Different species of living organisms have different numbers of 7; ekd zd 84gt.r9ooqr;2 yaoxgenes characteristic to them. The table shows the estimated nra2d4r7yo;.8xkg;zeot d o9q umber 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 colour. ;fz iif.8m6-q 3r smoeIf the pea plants M8fme. r6;iqo-m fzs3iendel 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 hemophilia uom7u.r4g.uiq jk;a 8i otj.h+qj p9+ have a daughter without hemophilia. Wh ;jot7.+89ukumq. hau r.ii4gq+opjjat are the possible genotypes of the daughter?

  A dihybrid cross was carried out between two sunflower plants (oh5 7 6vuri6kr6mg1muHelianthus annuus) to see if the genes for seed number and seed shape are linked. The critical valu 6ih mog157m66 vrrkuue 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 A and blood type B can have a child1p :xmb,o.scs with blood tys:bso.c ,p 1xmpe O.

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

3.Explain the role of inheritance in genetic diseases.