A man and a woman hav*a,p,t pj rmpl1v7+ pie a daughter and a son. Their daughter has normal vision, but their son is colourblind. Which one of+,*p pvp7 tamp1ri,jl these genotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic cell in a hum go +gv vip-;un63vc*man male?

  There are two alleles for flower colour in snapdragons. However, the rathf9bag)u, gd5rw0 a9gi -.sesult of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, re, uhw99agd5a b0sitafg g-r.)d, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to the correct defin34c9;03pdfmnorz;b j g mn 8yxition?

  Which of these statements is a correct definition for a genepa0 (c;l tp;iq?

  The diagram shows a 7te-.* 8 wzaaurq+w :..3y*ikcu vohb: mcos ppair of homologous chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were csgk1sx n 4hw.+ ykb u;q3x9x0erossed in an experiment. Which row shows the expected phenotypic ratios of the3u k.4x0ex9 ;ngwh1ykqs x+sb offspring resulting from this cross?

  In some animals, the agouti allele causes individual hairs to have a banded pa f :n(l9gkueyavwg5 17ttern. The non-agouti allele causes hk 157nvg9leafu gw(: yairs 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 shauf s5hdw1*v4qpe in individual pea plants was either round or wrinkled. The results of an experimental cross yielded 315 offspring with round seeds and 105 offspring with wrinkled seeds. fhu qv*4 d1w5s

Which row in the table below states the most likely genotypes of the parents?

  Neurons of the fruit fly (Drosophila m-;voe-le:w j velanogaster) have 8 chromosomes. How many chromosomes are in a fertilised oocyte o-jov; e l-w:evf a fruit fly?

  When does the random orientation of homol smplv6v, t8p0ogous chromosome pairs occur?

The majority of the genes in the human 7hnl:i - frv:lgenome have already been mapped, meaning the exact locati r: vll-7hn:fions 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 definfd7z9uqo;va l/;o w:r ition of linked genes?

  The diagram shows a k1 c:7z urdoqq60n 79te+ ruixsaryogram of a brown male rat (Rattus norvegicus). Which arrow is pointing to a pair of autos rusz:q1 7ux7e+cr06qtnoi 9 domes?

  Mendel observed that there are two possi9r- c+1gmwyksble variations of flower colour in pea plants, purple and white. After a mrs w-gy9c1+ kgenetic 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 of birth weight of children b ; 4r0rf+cv+epl.vkr gorn in London in 1991. 4kvep.f; gv0+r+cr rl

  Which of these traitidat1qc3 fddm6 x5m25* ul ay/s is an example of continuous variation?

  Which row correctly describes diploid and hapld .d-uwkn2flhv j ;09yoid cells in humans?

  The following table shows the diplo06xqf:g ,hqasie-p8 sid chromosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused d:z)i2mbk woms)k:n 2gm05xlby 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 child with blood type O. Wha,lxyft w7g;.wzaf+c4 zm3(i r t are the possible genotypes of the biological fa f czr iza;3tw+ ym(w.g4,x7lfther?

  Which row shows the correct annotation-(kz fr g)wl(iep+)+x eiowj0 of the alleles for blood groups?

  Which of these statements are true for alle /bol2g f3ikwa,g nz16les?
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 sprc m7oau,hc6,gza an2 3ead of malaria across the continent of Ahza m3 ,,agco7 unca26frica.


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 f+6(n1z ,*wj jonhosu 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,*(jh+ uwnsno6 jzo 1f 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 uneh *dhy m7luu-2pu,b 4linked genes.

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

Sickle cell anaemia is caused by wh wu83: tww(ethe 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 homozygous for m1t wl9; 72zrdf 2nsl,8rwyuibrown, long hair and a female cat that has blacim,r y2ls ;f znd7 t9w8rlu1w2k, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamond-shaped seedsmk hu:mn0zrne tj22g1 /cbh49 (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) is dominant over /2 rht nh u mjg:e9z0kbcn214mshort 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 shekq..aq*2 b uzort 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, stra*equk2. bzq a.ight-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 th0(q we- e49jnurrll*47oqg y ge condition shown in the pedigree chart b( jqqol 0u4lrg nyg79 e-4re*welow?

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

  Which of these statements about uq6jalo1f- y1v0n ll(genetic 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 distriba)84z+ep .c xl+ld0i mutfz z3ution.

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 shownr* cx974 mepfdpor/x2 in the pedigree chart is X-linked recessive and not autd /4crr fm29po*pxe 7xosomal recessive?

  Different species of living organisms have diffdg7/g. at/dmmsn-+ku6n8v h herent numbers of genes characteristic to them. The table shows the estimated number of genes for five speci hk.h nu8dn-+6a/dg/vm g7smtes.
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 flower colour3/f39m.mjzfd*zo zly eg0u8 k jt+l.t. If the pea plants Mendel was studying can +.*zz /t8 jk3j dtmf0lzm.uoyf3lge9 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 female13;k :j gnnuxn without hemophilia have a daughter without hemophilia. What are the possible genotypes of the daughn31g;x: nkjnu ter?

  A dihybrid cross was carried out between two sunflower plakem m12uai;f1 nts (Helianthus annuus) to see if the genes for seed number and seed shape are linked. Th2e k1 1m;aimfue 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 wit pigc0nw9jo).5 av idr*f ,t*jh blood type A and blood type B can have a child with bloi* prfwjv*jgi5n9 cd,.at)o0od type O.

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

3.Explain the role of inheritance in genetic diseases.