A man and a woman have a daughter and a son. Their daughteh2nk4. fz- aear has normal vision, but t- ah e4.kfzn2aheir son is colourblind. Which one of these genotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a so,tz jjr/jv 22omatic cell in a human male?

  There are two alleles for flower colour in snapdre* rw88vy (bhrs pht ba;3i.w7agons. However, the result of a cross between two abr87(.wipwtr*v 8eshhb 3 y;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 the correct definition?x(oziskc/(t cv vy +5;yq1ue1

  Which of these statements nvy* legh5./5:z5ka)jgx*7k1mmyccjn ) yh eis a correct definition for a gene?

  The diagram shows a pair of hadcv:.r-kfcqgmj6;;- eo fq 5 omologous chromosomes.

How many loci are shown?

  Two individuals, heterozygous f/hz; 7tf3l awsor a specific trait, were crossed in an experiment. Which row shows thewz a/f3lst 7h; expected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agj(msrc9t 2,zz r :0ezrouti allele causes individual hairs to have a banded pattern. s(:r0erm,j2rczt 9zz The non-agouti allele causes 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 plyjqu0i 6k j1d0if x)q3ihf 92mants was either round or wrinkled. The results of an experimental cross yielded 315 offspring with round seeds anjif f0x 0hqji69q)i 3y21 mkdud 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 chromosomes. How 7+q2zal z /toghn ou10many chromosomes are in a fertil1ooug+atl z2 z7hq0n/ised oocyte of a fruit fly?

  When does the random orientation of homo-d.) d yp9j8 w; znhjmp79xgzzlogous chromosome pairs occur?

The majority of the genes in the human genome hh4 y:- c 3- zjketv ysp1on trm1r9d12zwzi-l-ave already been mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one representatiodsc-z -3erj-4t-wzzn h2iyp:11 vryto 91k lmn 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 l63lclvh ztt:c-v5c,m inked genes?

  The diagram shows a karyogram of a brown male rat (Rattus 1+4q c9hku+ez/ko qdinorvegicus). Which arrow is pointing to a paiz9kki+uqq4 cd1/ eh+or of autosomes?

  Mendel observed that there are two possible variations of flowjh2uh )zsz7;g er colour in pea plants, purple and white. After a genetic cross, the ratio of plants with purple flowers to whih)7sz; zg uhj2te flowers is 1:1. What were the genotypes of the parents?

  The graph shows the frequency of bibw x.0:nwis*p- lwk 4nrth weight of children born in London in 1991wsipl :k ww -*b0x.nn4.

  Which of these traits is ayd8/nl0* aa fmslg/1kef+vy1 n example of continuous variation?

  Which row correctly describes diploid and h rg7 j*tho js3mzx029xaploid cells in humans?

  The following table shows the diploid chromosome number of a range of specie axw-3 /vbq ;x7w6bf;y jzdp:rlxv-s5s.

Which of these statements is correct?

  Sickle cell anaemia is caus wa,rl3ay+vi ov x) xow, y*x3h8,ljf;ed 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 had a chi31vfol9 (qvm qr0l *j8i 8pieald with blood type O. What are the possible genotypes o0limr v *q18l9e(ivf8po3a jqf the biological father?

  Which row shows the correct annotation of the xv 2czlth/v 6z u*h,2falleles for blood groups?

  Which of these statements are true for alleles.*2uk0 z(s(ye ; t:ibamus0aw lhmtc* ?
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 (h)ayu ya eo/1and the spread of malaria across the continent o)/uoe ayy(h1a f 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 8 p)8 kl(d b1q9fe +kmhogorj,is determined by a number of genes. Brown colour (B) is dominaq9 kkp+fr 81d8omjo(b , glh)ent 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 linked and t qci)r 37n7 v+af+2qha yxi(lunlinked genes.

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

Sickle cell anaemia is caused by the allele:;muz ao+9*g lx yeh 1e5u/vkx 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 betweeni9y r(ca;2(l wzotpg: a male cat that is homozygous for brown, long hair and a female cat that has black, y2z:; ctpi(o(awl g 9rshort hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the am6fl5z :ey/ sm9(rqysk u( 6cekv*f, mllele for diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) is dominant overz5( l e:y9q(r kf/me s6su*6m kfc,mvy 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 hi q:b9acfw+5;f : dygjrmghf/p, 7ft3air (l), and curly hair (C) is dominant to straight hair (c). A test crossdrf7+ q/,f3yji:5ba9 hfp c:;f tmwgg 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 pedigree d80-wi(mg+qp4,wg6 fpzg jmx chart bwpgqj68m(z4 xw0, p-dmg+ f igelow?

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

  Which of these statements about genetic disorders is/are corr3yxwude,)+ga -nl*lsfkj5-yllt0u 7 ect?

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 ao*)njxpe7q4ef3 y3 xx*d2 qpx 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 disord )u4zgu-f jgv4er shown in the pedigree chart is X-linkedf-uu g4vjg z)4 recessive and not autosomal recessive?

  Different species of ;apf;sui vm41living organisms have different numbers of genes characteristic to them. The table shows the p1uvms;a i 4f;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 characterivuo0uux9yk67vw b, q5+ nbz v:c0sfi .stics of pea plants, including flower colour. If the pea plants Mendel was studying can only be white or purple anbq .oi5,07su +v06c :vbv z xu9kwfuynd follow the rules of Mendelian genetics, which of these statements was correct?

  A biological male with hemophilia and a biological f,:qa- o1u brgjhb;-: 8qm 3g)/(qaxdiw emfxc emale without hemophilia have a daughter;x ab( 1-wmhug8,car:q/m di -jg)fqeqo b3:x without hemophilia. What are the possible genotypes of the daughter?

  A dihybrid cross was carried out between two sunflower plants (Heliat; jkg (lc((cpnthus annuus) to see if the genes for seed number and seed shape are linked. The critical value for the chi-squarlt(jk (;(gcpc ed 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 parente c+(;r qicu.is with blood type A and blood type B can have a child with blood t( cci+ur i.;eqype O.

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

3.Explain the role of inheritance in genetic diseases.