A man and a woman have a daughter and a son. Their daughter has nog8ee2 wmy:j:9j6 vhe trmal vision, but their son is col ejt8e 6 2mg::eyjh9wvourblind. Which one of these genotypes could be correct for the biological mother?

  Which diagram shows the sexw8wdt6- -7f1k:9u uxgrlryc e chromosomes of a somatic cell in a human male?

  There are two alleles for flower colour in snaptk) -fv+cw9v rdragons. However, the result of a cross between t -vcr w)fkv9+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 match4 ;)s1pqx kmsoed to the correct definition?

  Which of these statements is a correct definitionae ;lzz (i)/vl for a gene?

  The diagram shows a pair of homologous chromoyxspm)t9f*qld5w ; f 5somes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were crosseqcc+0z viosu2 q2 5g:9gmvz,s c9lj,ud in an experiment. Which row shows the expected phenotypic ratios of the offspring revugqvci9 lc5,jz+9zc s0um q so:g2 2,sulting from this cross?

  In some animals, the agougfye68 h 6/k: ljl0eyoti allele causes individual hairs to have a banded pattern. The non-agooj6e 86l0yh kelfg:y/uti 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:jnm1cy5 /2-aw igjgx+:m zye shape in individual pea plants was either round or wrinkled. The results of an experimental cross yielde1w2 mizym:cj-5 j+ag :xygne /d 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 melanogaster) have 8*on755w ja cq7qikj )m63/l*ggsexqn chromosomes. How many chromosomes are in a fertilised oocyte of a ojqxqjq) k6ce/g7s5n nw *7 lmi*5ga3fruit fly?

  When does the random orientation of homologous chromose+ ;c+qqsvg 5nome pairs occur?

The majority of the genes in the human genome have already been 7gmu*0 q -r 0g-3xq4 hidz.pieosphv1mapped, meaning the exact loqum07i10hz*vdxs g q -3rpe.ghio- p4cations of the genes on chromosomes are 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 tf )ekmpv)9* ++dgbad definition of linked genes?

  The diagram shows a karyogram of a brown male rat )s vdz wz+j5gs;51gkv(Rattus norvegicus). Which arrow5;ksg+1vwz) zs djv g5 is pointing to a pair of autosomes?

  Mendel observed that there are two possible variations of flower colo a)t v,(r7oysnn..tqi;fal w/ur 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 t nav, afw.i ns(y ;qtol/)7.rparents?

  The graph shows the frequency of inko t rufgw4(+j0/*i birth weight of children born in London in 1991.gtk0i( /fiwn 4u*roj+

  Which of these traits is an example of continuous variatione;n+br7big wj)6;ffp?

  Which row correctly describes diploid and haploid cells in humans? ongd(j89yg;va8 -)z*m 5yp n, tifwj w

  The following table shows the diploid chromosome number of a range of spd1yff-4 +-pazh wk j1vecies.

Which of these statements is correct?

  Sickle cell anaemia is caused by a rr2:eh8m ,ok/ v60nmr yb r9crzecessive 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 type4rxvgv+ )r0 pw O. What are the possible genotypes of the bi4vpgw+r vr)0x ological father?

  Which row shows the correct annotation of the ( hp+ z7evfwv9;3l;g9k kjk vralleles for blood groups?

  Which of these statements are true foy8fwq1isa6 e i3n 7e:yr 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 okr9,eje*h h6and the spread of malaria across the c, 9h eokehjr*6ontinent 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 febr.z4 y afkvh lp2n*k,,1j+r(h/mf determined by a number of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) colour (P+ra1j* n he (lk v2zhrfmf,pky4bf,/ .) 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 ui : 4getdu,zdopzl35f1vf+ 3pd s-g+i nlinked genes.

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

Sickle cell anaemia isl/ s0 vph-uh/i caused 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 homozygo:rr8e ,vmwuwc(vx3h - us for brown, long hair and a female cat that has black, sh8-3,mwrruw ve: (cxv hort hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), thd;9 njw9imnx1 +cj8mip l o-6be allele for diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L)8w-;6+19m dpin9on bjxjml c i 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 porcell lldyrc4.f;us e(cx29us), long hair (L) is dominant to short hair (l), and curly hair (C) is dominant to straight hair (c)f2c4 ursd9elc ; l.xy(. 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 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 inherit s+z0pnkrix 5dm4 /;rrance of the condition shown in the pedigree chart belowzrk;mp 4/5+ rd snxri0?

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

  Which of these statements about genetic di t929xmnco,fig 3p9l lsorders 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 polygenica9lg( *)rnnmu 1bus9 b traits 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 ootokz .sp(-+u . rbno1f the disorder shown in the pedigree chart is X-linked recessin kpu1.s r(toz.+ o-bove and not autosomal recessive?

  Different species of living organisms have different numbers of gehfk:92fa+dtv r1m e)t nes characteristic to them. The taf d2: vtrk)t+9fme 1hable shows the 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 charac7zmari0grdd0;s * + jiteristics of pea plants, including flower colour. If the pea plants Mendel was studying can only be white or purple and+0ri s0dg*7mdz arji; follow the rules of Mendelian genetics, which of these statements was correct?

  A biological male with hemrflw3;: u+zb iophilia and a biological female without hemophilia have a daughter without hemophilia. What are the possible genotypes of the daughter wb+z:i;ful3r?

  A dihybrid cross was carried out between two sunflower plan r8gjh9t kk:2zts (Helianthus annuus) :28t r gk9kjhzto 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 the chi-squared test was 10.05; what does this indicate?

1.Explain how parents with blood type A and blood type B cangqqwg 7vc2xqm7/ wclntl;6 -8 have a child with blxmql7n-6qgw7cc2/ 8w qtl v g;ood type O.

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

3.Explain the role of inheritance in genetic diseases.