A man and a woman have a daughter and a su .m a/rw ap0txe613rl1ijkoc;a/ z +b+z0eoyon. Their daughter has normal vision, but tho3kate/il ;w r a+0 z 1u.ocz10yejbx+ p6ar/meir son is colourblind. Which one of these genotypes could be correct for the biological mother?

  Which diagram shows n;lx pi7q 5rgmf2w2 n4the sex chromosomes of a somatic cell in a human male?

  There are two alleles for flower cq8 pdcb7ssz56 olour in snapdragons. However, the result of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red, ws 7bsd 8z6pqc5hite and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to the correct definit*lqvc)(yrpb nc:f14 l obfu18ion?

  Which of these statements is a correct ddw md ,tf zql55i+hx13efinition for a gene?

  The diagram shows a pair of homologous chrcnt6-7jnusr */o;s.h8vrvsjomosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were crossed in an experrieh. jbc09 w(iment. Which row shows the expected phenotypic ratje( .chb9i0 wrios of the offspring resulting from this cross?

  In some animals, the agouti allele causes individual hairs to habw/za 1;cg j1zve a banded pattern. The non-agouti allele causes hairs to be a sing1zj zw1abg; c/le 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 eithe7zf-: g*xy(cg d0ouyk1o fr* jr round or wrinkled. The results of an experimental cross yielded 315 offspring with 0 1k*cdr uyj*yx-(gg:fzfo7oround 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 f:-3 -mg)hdxzh vamaa(ly (Drosophila melanogaster) have 8 chromosomes. How many chromosomes are in a fertilised ox(gmd m ah3hz av:a)--ocyte of a fruit fly?

  When does the random orientatil b6xv ,6 .s(exljm:wwon of homologous chromosome pairs occur?

The majority of the genes in the human genome have azy*d5 u0l-gsdtoof +6lready been mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one representd0szu-5ltfoo6* gd y +ation 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 linked geneso1 .u8iq nfy8j?

  The diagram shows a karyogram of a brown male rat (Rattus norvegicus)bnk*z*r g: 6pnuk:8r d/up9vf . Which arrow is pointing to a pair of aut 8/kgr6v:n:ur **ufbkp dz9pnosomes?

  Mendel observed that there are two possible variations of flower colour ;eat6e kpmx4;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 ke tp6xe;; am4the genotypes of the parents?

  The graph shows the frequency of birth weight of children born in Londbio egpe+gl5fwq :0()on in 1991. )wel5p:+0gqfbi eg o(

  Which of these traits is an example of continuous - ib.o0*nkxdq variation?

  Which row correctly de71 hxf2lp ugia 4f,+uhscribes diploid and haploid cells in humans?

  The following table shows the diploid chromosome number of a ran,ud;;lazuou- 4r8o y tge of species.

Which of these statements is correct?

  Sickle cell anaemia is caused(ddegavjw.w lb/( 1.zygd4;gmm+,ci by 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 bloodpz.y5q0nb) j5n+2 ku4dov8 lpasmy87nurms 9 type A had a child with blood type O. What are the possible genotypes of theduyn.ku45qla b s 898m+z2 no 507pnvyrmjsp) biological father?

  Which row shows the correct annotation of thc0 y tb. * *j 6g*u6f,*pzhwiandc6youe alleles for blood groups?

  Which of these statements are true f,cq q/ o6u4 cdj,fci+nor 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 and t i).pfm.xqn,g s8 nyf:he spread of malaria across the continent of Afri psnfixnf. )qy8:,.mg ca.


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 prkl fza8a rlas r *ussj17zv-y34ltwb,8g/ e0 4zewalskii), fur colour is determined by a number of genes. Brown colour (B) is df su-vsjbazt3 r *1r s8780z gk,/llela44y awominant 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 linked a((p4scp q kwpi4)l9y9ts .gsr nd unlinked genes.

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

Sickle cell anaemia is causedr4zpa4fh+8fno l 8 3ve 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 fwq-l x -u1ew3cat that is homozygous for brown, long hair and a female cat that has black, short haiwue l13qwx-f- r.


Which of the offspring has a recombinant genotype?

  In dandelions (Tarax l;xp6(vg8oys acum officinale), the allele for diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long sgopxl6v 8;y(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) is dominaybmstx5-th-3g 9a8tuk 1h,uogp)o b 2nt 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, h1b-spauo29utk , x3-bg8gm to th 5)ystraight-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 thdu6,iz16o,j hx lc4 vfe inheritance of the condition shown in the pedigree chart below?fi6vc d,x 14l jo6,zhu

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

  Which of these statements about genetic disb5 d qk 7n5-xm*bp7iyporders 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 polygenfx9eyo b sp d3(+)wto:ic 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*9;g/w e.(gtnol wfyx inheritance of the disorder shown in the pedigree chart is X-linked recessive andg nw gel9.xo*yf t/;(w not autosomal recessive?

  Different species of living organisms have diff +br; 0ow4e)rq3rilhs erent numbers of genes characteristic to them. The table sho4; r0qhl erow 3sri)b+ws 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 pe rbebv 3p8uoe0mdn; x8 )w3(h(l5rhfsa plants, including flower colour. If the pea plants Mendel was studying can only be white or purple and fol3(08s);vpen rdhubm b3f 8w leoh(r5xlow the rules of Mendelian genetics, which of these statements was correct?

  A biological male with hemophilia and/m r--v6iv 1glq5p hj sh2cll/l,s9rm a biological female without hemophilia have a daughter without hemqs9hri-hrv6p1lc / / m l25l,mvj gsl-ophilia. What are the possible genotypes of the daughter?

  A dihybrid cross was carried out between two sunflower plants (Helianthus annuus nz -cf,y5l(x*2dxlm:lzxd 2j) todl2n lcxlxf-myz z5d :j2x(,* 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 can have a child with forq f-b;q0:t*b6qr.9pip mibfi*r9i qprbpqt; :. mfq-b6o0lood type O.

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

3.Explain the role of inheritance in genetic diseases.