A man and a woman have a daughter and a son. Th.nz77a:ky-/feji0 wtx igr *xeir daughter has normal vision, but their son is colourblind. Which one o 0: i-xjn*r.ak fe7y7itzgw/xf these genotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic cell in a human male? crq;h7/ p3;0igyizrc

  There are two alleles for flower coloxb5+ 7:9jcouw4s+ k4 yuycr xx-)j nodur in snapdragons. However, the result of a cross between two heterozo5xyw kn)u4d:s+uxo9 j47yb rc c-+xj ygous 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 deybtr 7c :hl*k1fl.h,l/sok .x finition?

  Which of these statements is a correct definition for a gene?ig cep,zx.t(5

  The diagram shows a pair of homologu+ do(.+tku2dz,,lc1 /bce3hcx sn)lw oxp. wous chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were crossed in an experimen/eh/oi87 .stvs8zpdd u h;.1q pcbw a(*(uxzyt. Which row shows the expected phenotypic ratios of the offspring resulting fctsy(b*qo phd88d/. ;(xvz7. ieuspha zu1w/ rom this cross?

  In some animals, the agouti allele causes individgy:h92adrlbql 2v9e l 7ey( s)ual hairs to have a banded pattern. The non-agouti allele causes hairs to be a single rlg sb72yhv(:a lel9)y92d qecolour. 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 rvhj bv a ja6g)7k6: q4lyad(j5ound or wrinkled. The resug(6 )6jlak4:h av 7jdjy5aqbvlts 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 me8sge rk+.f j9jlanogaster) have 8 chromosomes. How many chromosome+r8jgsk .f9 jes are in a fertilised oocyte of a fruit fly?

  When does the random orientation5e:.w.l lxh j4 zty.rl of homologous chromosome pairs occur?

The majority of the genes in the human genome have alrekb. *h oupej ,r,s(0 oy6wm(ufady been mapped, meaning the exact locations o,6(opbh (rfuujsmo e* ,.0kywf 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 definition of cfy+4lg)dfojbt0i, d7(zxsyf1 )tq+ linked genes?

  The diagram shows a karyogram of a brown male rat (Rattus l k) )t/s4 ih92djoa7gwrgc* ax1kn6ynorvegicus). Which arrow is pointing to a paitj c9)l nhgsx rdak/71 kgia2wy)*6o4r of autosomes?

  Mendel observed that there are two possible variations of floonpa( glae +l;7t,e m7wer colour in pea plants, purple and white. After a genetic cross, the ratio onlt m7,pa e;e (ag7ol+f 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 childr i/b9mvj)b iu:l (b+ kc3x2rtva;m )cren born in London in 1991. 3trbcvli )/;9b im2( bk)va+: mcrjxu

  Which of these traits is an exampwo3:vw:z;9 ; 7catbm5b 3zhz*uek ghvle of continuous variation?

  Which row correctly describes d -3pra2xvf 1q3 gfz:haiploid and haploid cells in humans?

  The following table shows the dipnpmw hl/;e qlnr*mw2g hz+n nkg+(l6ti:5; 2cloid chromosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessijtyka -3h c 8-mkqx0:6kkznp5ve 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 ,o p;qz/8zqwpwith blood type O. What are the possible genotypes of ,oq; /ppzwz8q the biological father?

  Which row shows the correct annotation of the alleles for blood3 k/aj*vxwp f7 groups?

  Which of these statements are true for a v 9 h)atlt:3p4yrd:kjlleles?
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 sp syend 2esu a5p2qjkg ;77o:-fread of malaria across the continent of227en u jfyepaod7ss: ;5gqk- 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), fu6/;l)b2fpf5 pb 8sytsiz2g h zr 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 dominant to onhb;pf8z fs26bt/ s)5lyi2 pzg e 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 unlinked ge inb f*n duqp4 k50/fq/jo,3vrnes.

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

Sickle cell anaemia is caused by the al lmy*4.e m/ )dz/jxotllele 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/r rasx19hi g4us for brown, long hair and a female cat gx4 / hr91irsathat has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamond xhv qwrt4s02b10 t0 n2od6did-shaped seeds (D) is dominant over oval-shaped seeds (d) and thddws4otd62t0 1x0i b0nq2 rhv e 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 c7k i 51+fhrpaszgzc e,,mg6 ;hair (L) is dominant to short hair (l), and curly hair (C) is dominant mhcc15sk, + ,fezgprza;g76 ito 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 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 p45 izf2 :9vuuon*t egfedigree chart bel 9nzf*eit5 vou2:guf 4ow?

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

  Which of these statements about genetic disor;t/4zg ekui( p)jmo6u8v*ldr 5y0 dps ders 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 +jq3 b)7r8 jk.hpfibl f, w*hican 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 of the disorder sho8+ zdzi9jaf72t 1rwhr wn in the pedigree chart is X-linked recessi2a 1 8rzfi9j +hztwdr7ve and not autosomal recessive?

  Different species of living organisms have different numbers of genes chara tkkbtkvp5;14zzf1)+) 8r0gxf ghaabcteristic to tht pg+k)fa5k4a )0;1x vkgh1 ztf rb8bzem. The table 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 characteristics of pea plants, incluu rad6d+nl ;m -j2ep2 bjsvd+:ding flower colour. If the pea plants Med abu2+ :dmjr+-pl je;dns2v6ndel 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 h.b 4ztkup;h:uemophilia have a daughter without hemophilia. What are the possible genotypes of tu:htu ;4zp.k bhe daughter?

  A dihybrid cross was carried out between two sunflower plants (Helianthus annin(s)u9w8m0y .e* ziiky ws3k uus) to see if the genes for seed number and seed shape are linked. s isukiy9 0.yenk)8iwwz (m*3The 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 n fegt2o ig d).2o56iwA and blood type B can have a child with blo 5ft6ig) 2n.egoio2wdod type O.

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

3.Explain the role of inheritance in genetic diseases.