A man and a woman have a i.bgg sj+ot q ;+2-waodaughter and a son. Their daughter has normal vision, but their son is colourblind. Which one of these goabstgwo+-.;i+q2 jg enotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a som andg5.( q*,2txxb e53xxljrs8w 7l kiatic cell in a human male?

  There are two alleles for flower colour in snapdragons. However, tl btqbu, ) 5 )vq6.egqb-f)rbzhe result of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red, white and pink flowers. Which is the most likely expv.zg,blb6 ube)r- qt)q fbq)5 lanation for this observation?

  Which keyword is matcpvmvf0rjbla 9l(: 1 xejt, j) 6,by(pfhed to the correct definition?

  Which of these statements is a correct dznd7m0(jf c*9 1sa9x cni:wup ji8am5 efinition for a gene?

  The diagram shows a pair of homologous chromosome s+12d-p kqck9l8-0si qxu q*k;iffcjs.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were croj-9wwn7 pfywxw;t2 a-ssed in an experiment. Which row shows the expected phenotypic ratios of the offspr2pww;x- ny-w 7f9awjting resulting from this cross?

  In some animals, the agouti allele causes individual hairs to have a banded patn u-;b g 1pa,0l4bs13wddk-co 9o6znkv/ wob atern. The non-agouti allele causes hairs to be a single colour. Individuals who are heterozygous have1z1-w,puagkko9;d- nbbcl6d/ v a 4ns oo0bw3 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 orb j4bfnr;3 h1y wrinkled. The results of an experimental cross yielded 315 offspring with round seeds and 105 offspring witj4 ryfbb1; n3hh wrinkled seeds.

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

  Neurons of the fruit f1ksq d1/ e:dghly (Drosophila melanogaster) have 8 chromosomes. How many chromosomes are in a fertilised oocyte of1qd1dek:/gh s a fruit fly?

  When does the random orientation of homologous ka82 - cxxai.jte- d2qchromosome pairs occur?

The majority of the genes in the human genome have already bwxiu7 g dhjr01 y:*2 *nhupux.hpt24deen mapped, meaning the exact lo: tj1p2y.d0n7u wdghrxi * x2p*uhu4hcations 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 definition of linke xmrk0) cq95gdd genes?

  The diagram shows a karyogram of a brown male rat (Rattus norvegicus).pr8s spq4*(bjag j:1q Which arrow is *p:s sp48j1( qba jgqrpointing to a pair of autosomes?

  Mendel observed that there are two possible vvsf h v9*o2v7dariations of flower colour in pea plants, purple and white. After a genetic cross, the ratio of plants with purple flowers to white flowers i9f2ho7 d*vsvvs 1:1. What were the genotypes of the parents?

  The graph shows the frequency of birth weight of ch n bornl:0r.y,ildren born in London in 1991. 0rln :ynr.,ob

  Which of these traits is an k.xa1.ul)pz5dm i0:xv 8gv wmexample of continuous variation?

  Which row correctly describes diploid and haploid cellvp v6ho7+b8 g f1lvfz;s in humans?

  The following table shows the diploid chromosome num.ep b8 b jf1l i+epc,vxinf.94ber of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a i-fmufv o3 :w8recessive 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 tykbi9v w3t9xw8u5loups- 6 1mwpe O. What are the possible genotu89wv txsbmk-w3p6u5wo9i l 1 ypes of the biological father?

  Which row shows the correct annotation of the alleles fa (0 fb:(jszwitd 5r)ara0vz5or blood groups?

  Which of these statements are true for allele7q(gwng7zpol eb8uy /p+* e k4s?
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 incidenc96kfncf4aopdro8 ,ga+0 f .sue of sickle cell anaemia and the spread of malaria across the co0p8 ,rfa.on 6oa9kd4u gsf+fcntinent 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 desoc-) etaao3ti4: 9u2gwe3 mepa6c h 4termined by a number of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) colour (P) is dominant to one 323:9 4ticgaa weu ho4eep6oa csm-)ttone (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 linke c+v;p)r0hywe qebt6 +d and unlinked genes.

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

Sickle cell anaemia is caused by thf7 qy6ii6cxw hzi9y 2,e 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 thc e/to:ti(llce8ya/6 at is homozygous for brown, long hair8(:/ioca eltlc/t ey6 and a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum 96zf; ro7 oftpofficinale), the allele for diamond-shaped seeds (D) is dominant over oval-shaped seeds 6p o r7ofz;ft9(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), lontee8ud n( bdm*(1;hnv g hair (L) is dominant to short hair (l), and curly hair (C) is dominant to straight hair (c). A test cross was c;dnmbtv8deeh( (n* 1u arried 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 ike+jnzs4+.9zjts.ri n the pedigree chart +nzi esj4sr .9+.tjz kbelow?

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

  Which of these statements about genetic disorders is/are correct?z* paz3 iw)j( nwz i03 *.j65zg.kjbpzwr)jgm

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 canp5 5k9yvan gm; g6gl0mw vpqo ;a/-uu* 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 inherita,am e+vaj3o (dq:k 7 t0lrp:zonce of the disorder shown in the pedigree chart is:ea+:z (dvtq3o0mpa7rko j ,l X-linked recessive and not autosomal recessive?

  Different species of living olqcxkq)9 xo7)mwee.ycyd;( 8 rganisms have different numbers of genes characteristic to them. The table shows the estimated number of genes for fivq8kyq(c )lc.x7xe dwo ; )yem9e 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 charactpa 05eq jj1d19mc(uqweristics of pea plants, including flower colour. If the pea plants Mendel was studying can only be white or purple1 d qapwj9uq5(me j0c1 and follow the rules of Mendelian genetics, which of these statements was correct?

  A biological male with hemophilia and a biologic,6zj lpo2 5p n;caa+9 ksklij2al female without hemophilia have a daughter without hemophilia. What are the possiblo6jacl l pzn,sa2kj92;5k+ p ie genotypes of the daughter?

  A dihybrid cross was carried out between two sunflower plants (Heliash :; 8b;9ys+gyhvjzunthus 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 level was 7.82. The calculated value for the chi-squared test wzgu h:vyh sjs+9;;y8bas 10.05; what does this indicate?

1.Explain how parents with blood type A and blood type B can haqz9u ib 21qrycs rw9ny8*ksr84y 14wkve a child with bik*q zsr1rk n18s4q8r92wy y b94 wyuclood type O.

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

3.Explain the role of inheritance in genetic diseases.