A man and a woman have a daughter and a son. Their daughter has normal v3 hxn.fwl3 nrpm11f;uision, but their son is colourblind. Which one of these genotypes could be correct for the biolfuhnf xn wm3 31l1p.;rogical mother?

  Which diagram shows the sex chromoso-lv5etgib k3t+ap9 2g mes of a somatic cell in a human male?

  There are two alleles for flower colour in snapdragons. Howeq-r0lt)j03 0 vkinammz3sb 8 gver, the result of a cro0m8nizg 0vb3tar)sk-mj l03 qss between two heterozygous 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 thhpteby r( 4 td1zrv.16e correct definition?

  Which of these statements is a correct definitia(fel e.3b3 /ilyz j+aon for a gene?

  The diagram shows a pair of homolo ml0/mbif6nnd vu2/pk1k +p3bgous chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a a wfpic+v*f3zl m9t70ar6eck/( 3jvr specific trait, were crossed in an experiment. jckzl+c3* 9aer/a6p73 ff 0v( rti wmvWhich row shows the expected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti allele causes f bj62mfj.q*m; i*kv;jdlnx f lu 4g:4 apup-;individual hairs to have a banded pattern. The non-agouti allele cam;f; fjfvl.quxj* p:* 2n 4kb;-6u adgjlm4ip uses 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 was either bwe3y6jg(aij(+e a/h round or wrinkled. The rewj3(h(i + 6 y/baeagejsults 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 melanogaste ax3xpbl)8 z/dud(uun9jsqd0,(-rw rr) have 8 chromosomes. How many chromosrq0r p8b us/xja)wd- xzu,u9n((l dd3omes are in a fertilised oocyte of a fruit fly?

  When does the random orientation of homologous chromosome pairs oo1qw ytw./d ) ): pw10aydaoolccur?

The majority of the genes iwr x eea isy+u2c,a*86n the human genome have already been mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one repres e+*wa x8u2y, cseai6rentation 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*jayriowi( ;p;n,lih 0 -g1 kw linked genes?

  The diagram shows a karyogram of a brown male rat (Rattus norvegicus). Whic;kaa mnd8xoqw.*ak+ 4 0g,*evsrn2mgh arrow is pm. **0aa;an+g2 k 84vnq,wxme drgkosointing to a pair of autosomes?

  Mendel observed that there are two possib 2haah9-xpwr ;le variations of flower colour in pea plants, purple and white. After a genea-29;wxphh r atic 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 qvi8x2d6 9hy tkxz6/ lnop6v*of birth weight of children born in London in 1991. 8t yn/ h oidz6 klp26vxx*6qv9

  Which of these traits is an examplfelbr,z+c0a9y7 n wms z 0v:n+e of continuous variation?

  Which row correctly describes diploid and )1(j7 m v lcsjxdcxt+bl*za*(haploid cells in humans?

  The following table shows the diploid chromosome number of a range yjv0(af, fv1 psvx+:kypj(5i of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a9svwc2qhg z; s. *0uuu 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 type O. What are*m m*wl3kyb1 o the yko1*bmw*l3m possible genotypes of the biological father?

  Which row shows the correct annotation of the 0 y-fgwcclz50alleles for blood groups?

  Which of these statement n od lra:4w1ql ((izcy crtd/5yhk2((a (sqc,s 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 incidence of sickle cell anaemia and thofmwi.g clrk44mv 6*7+ rg8dt e spread of malaria across the cond4v.o4imkt*+gfg r6lwr c7m8 tinent 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 isr x66wv* 5g3mjimos:k determined by a number of gen*v5roiwgj6 sx m:36k mes. Brown colour (B) is dominant to sandy colour (b) and an ombre (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 lin r-yng:yw (1w6q7s uskked and unlinked genes.

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

Sickle cell anaemia is caused by the als:3 8zp* -(csp sytuhzlele 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 beh;c;r f0 bgb0wdp-1uttween a male cat that is homozygous for brown, long hair and a female cat that has black, short hairbtfw-; g p; ubcdr00h1.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamond-shaped sz )o+2cs 7rcgzeeds (D) is dominant over oval-shaped seeds (d) and the allele for long se) 7c r2zg+coszeds (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 (s9blmfaut.;se z4kifob7uf-q 2*6u. L) is 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 chi-squared test (χ2)fmuz-ub*s e74 9ito fk;af.6q .2bsul 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 pedigree/ a;knx) 4kbwyvo j,s* chart 4;,kv*s kaybnx/w)o jbelow?

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

  Which of these statements about gqk1 ,5dk4em lbenetic 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 normal distribulu/h)tarb* 9vpm i;p*tion.

2.Outline the differences and similarities between homologous chromosomes.

3.Explain why expected and observed Mendelian ratios may differ.

  What suggests that tdo3v exogin/60;w9 sn he inheritance of the disorder shown in the pedigree chart is X-linked recessive and not autosomal recessiv 0 vw ix/ogd;9n3nso6ee?

  Different species of living organisms have diff(ef ie jar n-h5-(;xmaerent numbers of genes characteristic to them. The table shows the estimated number of genes imfe x ;- -j5earn((hafor 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 flower1)lrpm7ln rb/qrv 8gs ecq)4/ colour. If the pea plants Mendel was studying c/ec71l rrng l / 4)qsmvq)rbp8an only be white or purple and follow the rules of Mendelian genetics, which of these statements was correct?

  A biological male with hemophilia and a7fi)y.rg,ib k biological female without hemophilia hav7iyi.k ,)b frge a daughter without hemophilia. What are the possible genotypes of the daughter?

  A dihybrid cross was carried out betwe9;* eeojym 9sbq;rz3gen two sunflower plants (Helianthus annuus) to see if oqjgr ;;s9ez e9*ymb3the 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; what does this indicate?

1.Explain how parents with blood type A andd pz6bx .r hatv.rsy/rld/*w+vz bvs/ b97n:. blood type B can have a child with bl+vd*v6a ns. lbbz7x: wsr.rv/drh9 ybz.t//pood type O.

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

3.Explain the role of inheritance in genetic diseases.