A man and a woman have acaiu fthnx(q;576*zn dm6, ga daughter and a son. Their daughter has normal vision, but their mn*tf c7 u(q 5x6;a,h6nzia dgson is colourblind. Which one of these genotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic md45lvem*j0zdrx( /t cell in a human male?

  There are two alleles for flower colour in snapdra hkojz;yd)n9o)b9xpv: du8 c ;gons. However, the result of a cross between two heterozygous plants yielded offspring with three dcuovkj ;o 9) dp z8)byhn:;d9xifferent observed phenotypes, red, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to the corf+g ymc , tdz5jggb-z8x0, o,zrect definition?

  Which of these statements is a correct defikt ewtx) z60f8a l8 pth.ncb9:nition for a gene?

  The diagram shows a pair of hoe+vx6l 1ohq;-bv i 6zkb p30qc4hr 7tomologous chromosomes.

How many loci are shown?

  Two individuals, heterozygous fb+o, b sxlj-5sor a specific trait, were crossed in an experiment. Which robo , +b-lsxj5sw shows the expected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti allele causes in8 yl nkg8v2l;mhqo72qdividual hairs to have a banded pattern. The non-agouti allele 8yq2k87hln2lv gmq ;o 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 plants was either round or g.+yf7h us4s 5a(xjlp wrinkled. Tgu slfapx4.y 7(5+js hhe results 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 melanogaster) have 8 chr-azw ;.nrr txyho0dh-2p( t e(omosomes. How many chromosom. hraeo( -t;t w0r2xpd(zny-hes are in a fertilised oocyte of a fruit fly?

  When does the random orientation of homolx8ndj05zq /) 2jnlpi0,8j1qnywz sb bogous chromosome pairs occur?

The majority of the genes in the human genome h(cp8c sqw alv(p)0 u3iave already been mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below sho(ipv3ap wcl(0scu8 q) ws 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 k.arl qac /c(1e;7rp hdefinition of linked genes?

  The diagram shows a karyogram of a brown male rat (Ra0qsjw*+xaelr m7-/kxttus norvegicus). Which arrow is pointing to a plmr-+x /kq* sjxw70eaair of autosomes?

  Mendel observed thatlrjnbnl+j)k2 /yg85lx+ zo:i there are two possible variations of flower colour in pea plants, purple and white. After a genetic cross, the ratio of plants with y 5nb/l2jlzl+i: j on+)8rxkg purple flowers to white flowers is 1:1. What were the genotypes of the parents?

  The graph shows the frequena 5 s2hn*dpf:dcy of birth weight of children born in London in 1991. n52dpf hs*a:d

  Which of these traits is an example of continuous vywzmv ,1 1+ -itxrv;prr-u x+rariation?

  Which row correctly des,pg ((gfh)ubl-vs x:ja* fa:tcribes diploid and haploid cells in humans?

  The following table shows the i6(a 63z(2/ktsnunshv9lhs udiploid chromosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a ru8;zypx p ;ifx k/13eg6 xfl0zecessive 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 arer*fjhpc4 e 8 .hohra9: theaf*c8jho4h:r 9r p.he possible genotypes of the biological father?

  Which row shows the correct d1.i*a 4dpgu)hhb- mlannotation of the alleles for blood groups?

  Which of these statements are true for alle4z8v)um)hmg3 rl c mz ru0if+ g8.xpr;les?
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 a7vej49p bk;tx ;p*pxthe spread of malaria across tbppt79p*4x akxv;j;e he continent 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), fv*yb ul *:6q keba(t3dl5uipw 1s60 nhur colour is determined by a number of genes. Brown colour (B) is dominbl61 dy is eua(b:npuvk*6l0q5*h 3twant 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 linm)n;-r dyn ;fiqb *h;nked and unlinked genes.

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

Sickle cell anaemia is caused by the allelsa.w;;;bg v lcu yw3nif:e0l3/r ir3de 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 betweenc- yl h/qzt2f 2op8l)d a male cat that is homozygous for brown, long hair and a fec2ydhqftpl2l)8o /- z male cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum off. eu8gwrcie3a +5 eyfro*q lz50+gx9oicinale), the allele for diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long q5ilwfu08ar*9e g.ye3ro zg5 +o c+ exseeds (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 c71w*i ,idg76altpua (L) is dominant to short hair (l), and curly hair (C) is dominan* gadcu6iai7pt w1,7lt 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) 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 pediwvql p 0;4s;yt5w /hitgree chart hqt5i ;lt/ ws40w ;ypvbelow?

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

  Which of these statements about genetic disor +fjl aycg1dqwqb d m49a*0+(01c baeqders 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 noce9kf0fcli h x47t4w ,rmal 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 shown in the pedigree cha* 84uorq; mkyort is X-linked recess o 4uymk*q8r;oive and not autosomal recessive?

  Different species of living organisms have different numbers of genes biag 7qs fw,+3dtvuw9 6rn a(;characteristic to them. The table sho;+ ufidtw bw,6g(93r saqn7v aws 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 pla,;1sq 6l lgy9,kormsunts, including flower colour. If the pea plants Mendel was studying can only be white or purple and follow the rulesl1smus,ql y ro,9k6;g of Mendelian genetics, which of these statements was correct?

  A biological male with hemophilia and a biologicazv1 st2bg )ot7p.u8g kl female without hemophilia have a daughter without hemop oug7z b tp8gksv)21.thilia. What are the possible genotypes of the daughter?

  A dihybrid cross was carried out between two sunflower(djaqdz8nyu/ ) ha/:z plants (Helianthus annuus) to 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)uyd(:za j dna8 q/z/h 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 can dt 3iu45lfjsl:.c hh,have a child with blood type l3jf5,t4h: dh ciu.sl O.

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

3.Explain the role of inheritance in genetic diseases.