A man and a woman have a daughter and a son. Their daughter ha 8n+h(bh.cnx u24(z c;0grhg;ulgc vos normal vision, but their son is colourblind. Which one of these genotypes could be correct for the biological moh8(rnz ;4lcuuh 0 ;ch (ogvbxn.gc 2+gther?

  Which diagram shows the sex chromosomes of a somatic cell in a humanwu2:htq i;v nv-ky*: y5dao 0r male?

  There are two alleles for flower colour in snapdragons. However, the result of bg*7kjbm+micm 6pc5/a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red, white and pink flowers. Which is the most likely exj5pk+ *m/6icgmbmcb7planation for this observation?

  Which keyword is matched to thyje :my.e9eja 4 e.gg mrrtgx *vu9:,,e correct definition?

  Which of these statements is a correct definition for a gw,. jl n6;f je+kk3kgr*he z/lene?

  The diagram shows a ,cbsdk+f 9r ,vpair of homologous chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were crossed in an experimenl)t 6mcpak, euy 7c9c/(,fo0u8ivg zlt. Which row shows the expected phenotypic ratios of the offsprc0 (c,k6ovl u9/8m ) ailfzp yetgu7,cing resulting from this cross?

  In some animals, the agouti allele causes individual hairs to have a bandedn 7l89;n 7p h-kn*at5oxs kcaf pattern. The non-agouti allele causes hairs to be a single colour. Individuals who are heterozygous have hairs wno77fhak* 9lxn -c5 pkns 8a;tith 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 cc)d75f ojp fhjd0:m4 in individual pea plants was either round or wrinkled. The results of an experimental cross yielded 315 offspring with round seeds and 1 0mhcc5fpdodj:4 7)fj05 offspring with wrinkled seeds.

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

  Neurons of the fruit fly (Drosophila cg 8l )otq ipe*f i+/qs04/rfqmelanogaster) have 8 chromosomes. How many chromosomes are il 8+csq04rfq/ogpie/)*f i qt n a fertilised oocyte of a fruit fly?

  When does the random orientation of homologous chx.sz6zp6g: or g 8/ra xm96fdl7+f datromosome pairs occur?

The majority of the genes in the human genome have already been mapped, meaning9,e lf6d jn7qumg ln-3::fm;.wlq sx v the exact locations of the genes on chromosomes are knxwlefmsgnjq;., f::v7uq-6l 39 n ldm own. 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 ofxo 4n 3,g. byogu.se*u linked genes?

  The diagram shows a karyogj.bze6)zxedlhv+ y2) ram of a brown male rat (Rattus norvegicus). Which arrow is pointing to a pair of autosomes? e)j l.2+bhx y)d6vzez

  Mendel observed that there are two possible varia 8*atfb: 3bckvnb hjiec/122wtions of flower colour in pea plants, purple and white. After a genetic cross, the ratio of plants with purp vajh1: c*tbei228c3/fnkbbw le flowers to white flowers is 1:1. What were the genotypes of the parents?

  The graph shows the frequency of birth weight of childreu. j(,l jt-zrxgzoxis /7k .m*n born in London in 1991. j gux ozix zlt/-(,.kr*.js 7m

  Which of these traits is an example of continuous variation? mp)n 72qjrtpp8vab 90

  Which row correctly describesdk-wt2 e8 wml6 diploid and haploid cells in humans?

  The following table shows the diploid chromosome number of af uy73kvm1eaepwm kr 8+ p.-y7 range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive allexu8xdboo h1 gd a:1w0(le (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 ch cxd14uqxy. 8nw4j f8qild with blood type O. What are th4j8nq 4 uc dxxf8w1qy.e possible genotypes of the biological father?

  Which row shows the correct annotation of the alleles for blood groupk0 *c stsy;9se.vel0ds?

  Which of these statements are true for alb1utceu-u 6 m7leles?
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 spread of malaria a-um*m1zh,3 ird/d ojm cross ,-1r dm3/mdiz*hmjuothe 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), fur colour is tn 74gztin.7s determined by a number of genes. Brown colour (B) is doms.i7ntzn7gt 4inant 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 l ep88xmd5wrvc zsp(*( t2oqg5inked and unlinked genes.

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

Sickle cell anaemia is ca*gm 7t47+np w a rbg )i/ejs9trg.nb;sused 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 catl.d/jq; e:y. uu2dxae that is homozygous for brown, long hair and a female cat that has black, short haiual jq2dd.. ;:ye/xu er.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum offic+ -qg2t-hvjsyb *7mwl inale), the allele for diamond-shaped seeds (D) is domina+h m7sv qj2yw*-g- bltnt over oval-shaped seeds (d) and the 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 hair (L) is7 jkbq4z7s q9v dominant to short 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, straight-haired guinea pigs and a chi-74zqsv jb7kq9 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 per-/n5h*vy fs s 67lmb ,dlovv/digree chart belo, sv *l5/lh6srb-vf nod/v7m yw?

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

  Which of these statements about genetic disorders is/are correctao*(wo(:oe- rzzz y5 v?

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 txjm qay9(- lehe/i:65l3q hdcraits 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 v*3.2cskbz3z 8 qs yxoinheritance of the disorder shown in the pedigree chart is X-linked recessive and nk*c2 s zzq 3xbo3s.vy8ot autosomal recessive?

  Different species of living organisms have different hjc3 g* j:clo,numbers of genes characteristic * :jghol c3c,jto them. 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 c y d bq+:k 2hdwf/;r31yl:jkpuharacteristics of pea plants, including flower colour. If the pea plants Mendel was studying can only be white or purple and follow the rules of Mendelian genetibfjh /yrp1ly2 3 ;wud:k+kqd :cs, which of these statements was correct?

  A biological male with sp0g)//m b whj nbn)n0hemophilia and a biological female without hemophilia have a daughter without hemophilia. What are the possible genotypes of ts)0m hjn bnp/b )n/g0whe daughter?

  A dihybrid cross was carried o7a 9;ofpm3*1zhghj ueut between two sunflower plants (Helianthus annuus) to see if the genes for seed number anhufe1ho37 ;jz* 9magpd 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 trz i xczn0mp*m.48xs 4ype A and blood type B can have a child with blo4 xc x8*sr4mmzi.znp 0od type O.

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

3.Explain the role of inheritance in genetic diseases.