A man and a woman have a daughter and .m(gz t,6uu i,i di)dbb(dd+rkq5ej+a son. Their daughter has normal vision, but their son is colourblind. Which one of these genotypes could be correct for the biological motherbgdb+ m)r6dku(e 5,udj, .q i d(zi+ti?

  Which diagram shows the sex chromosomes of a somatic cell in a rb oqdjt;mf1i- 9ihh; .2w 7uuhuman male?

  There are two alleles for flower colour in snapdragons. However, ;ttr7ge a.cwc ,l *qb,the result of a cross between two heterogc ;r,tct.*l ea,qbw7zygous 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 matched to the corretxty-- h6 1,+z3.n elg h0ofj/jngr bwct definition?

  Which of these statements fia9hj2 wgcf1a 5 zg31kure1+ is a correct definition for a gene?

  The diagram shows a pair of homologouhm6i4uvr: od hz1rp 5(s chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were crossed in an gl r3k/34c9wj i 9dycfb3cuz)experiment. Which row shows the expecteg)d r9yfi /wc39z3kul3bcc4jd phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti allelfoy 6;qhm55ra8mkh6u e causes individual hairs to have a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuaayf 5h6rqm5uo hk6; 8mls 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 seedmll), id h7 1jd:+skdrln de:/ shape in individual pea plants was either round or wrinkled. The results of an experimental cross yielded 315 offspring with roun,erl:dj d:idkm /d+1 l) h7lsnd 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 chromosgd7k+cqbp eu9 zz;)k8omes. How many chregkd zb8)zq7k u9c+p;omosomes are in a fertilised oocyte of a fruit fly?

  When does the random orientation of homologous chrotpk0pc8e-b x( mosome pairs occur?

The majority of the geisjlup861n)q nes in the human genome have already been mapped, meaning the exact locations of the genes on chromosomes an l 6pj8qi)su1re 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 defid6zr/ocs.h h.rk q hive 9q-(b22sdr4nition of linked genes?

  The diagram shows a karyogram of a brownbdipnj34l n.f 3f,2ud male rat (Rattus norvegicus). Which arrow is pointing tjun43 nbp2d f,. dlif3o a pair of autosomes?

  Mendel observed that there +zicu.p( vz2v are two 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 parents?z.(u+viv2 pcz

  The graph shows the frequency of birth weight of children born ij q- s5zu03: gmmsnq;rn London in 1991. s -qsq5 g;m:jrmn3 0uz

  Which of these traits is an exa- b a)/+7bmv2yggdp enrcd /v3mple of continuous variation?

  Which row correctly describes diploid and haploid cellp5 ;on gd8.c-0sowk,w* hhuxys in humans?

  The following table shows the diploiddn v0g 22 q,6 o8fw4cvl.stg8cobb y4w chromosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by((qvnh,es 5,uv g2kxd rgrkbrxko 46(n4hy -5 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 had a child with blood typet1l 4yug gl,3g O. What are the possible ggl gu, g34yt1lenotypes of the biological father?

  Which row shows the correct annotation of the alleles for blood gro*4ont wh4x: g2 v hnw6hu cfr*h7d5d*qups?

  Which of these statements arej2z h(vk5v8dl eolj88ol .9 pe 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 incid*x-se3tq)7h u jdkn(q ence of sickle cell anaemia and the spread of malaria across the continenj-eh(* q )x 7ntkqu3dst 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 detmjopmz8gpt5w2 wv ,3 e /vt.;oj(o .mdermined by a number of genes. Brown colour (B) is dominant to sandy colour (b) and an ombrez/.vp moeomp 5 tvo82mw(jjt; ,.3wgd (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 lina .wn0 y 5u.la.rk4vndked and unlinked genes.

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

Sickle cell anaemia is cy tau,a3k1 4iyh5 wyimtf) qx 049ql(haused 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 bs:. p5aabifmg e9 /ox() uj7ayetween a male cat that is homozygous for brown, long hair and a female cat that has black, shx j)5amp7bia:.(oyu /9seg f aort hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for ; + rrqfnsh+n.diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) is dominant over s+n+;rrfsq .n hhort 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 57vw, sut ;(u ip;eigq8fi4khto short hair (l), and curly hair (C) is dominant to straight hair (c). A test; ku8iv wui,etp 4f;57g (sqih 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 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 gc3k/q f0t j(b.p+:hrefm6 qy pedigree chart0c/k p+6mhy:ff rjqb3q .tg(e below?

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

  Which of these statements about genetic disorders is/are f 3bs2(obwr-4wj;obd 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 norms,p a26 l e -q*dy,q(jga */xrmum5zigal 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- ie.gxqbab5(c7n5yo the disorder shown in the pedigree chart is X-linked recessive and not autosoma-y.qbogeaxb i (755ncl recessive?

  Different species of living organisms hav-zmrzhtkid *)w0d9 x,www e1uk l,/g. e different numbers of genes characteristic to them. The table shows the estimated nu1dz. e*tkhi-9,,)/mlgwk w w0xzdwr 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 tmo(*2h4t:ba nav+hu flower colour. If the pea plants h ba2 o*+4hn(avt:tmuMendel 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 aq -7gdqbdcs f+mf2q3z+ig n:+ifhy 2.nd a biological female without hemophilia have a daught7n.+bqd-q:+h y fm2q 3i 2gsdgzfcif+er without hemophilia. What are the possible genotypes of the daughter?

  A dihybrid cross was carried out between two sunflower plants (Hm)ksjt ; 49wwugty+d9elianthus annuus) to see if the genes for seed number and seed shape are linked. The critical valu)9d49twgw;ms u yk+tje 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 withkb6 ph519uabwq 1d3on blood type A and blood type B can have a child with blood tqh3o1 195 6kwp uanbdbype O.

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

3.Explain the role of inheritance in genetic diseases.