A man and a woman have a daughter aoa(,vt + pbs;xnd a son. Their daughter has normal vision, but their sx o;tb(v +,pason is colourblind. Which one of these genotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic cell in a human afc7 ri1 psi;6kin9(ewn.,2 g5h aefoiy.xk+ male?

  There are two alleles for flo3 sfmweupq2b:d) +kyy-j0 w jxz)/1 brwer colour in snapdragons. However, the result of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red, white and pi: kfdm1 b2+uj0/-wqbrw3jy)y )exz spnk flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to the am uzvqxyy 6n758 )rs5c7a 7dgcorrect definition?

  Which of these statements is a correct defini g7g4st1pfnnnuqn8 ; -)0qmrrtion for a gene?

  The diagram shows a pair of homologod vovmw0g)b2e 91b kv*us chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were crossed in 7oliojiytn w8)p 70)r an experiment. Which row shows the expected phenotypic ratios of the ofi87ljnrp)o7 y w)ot0 ifspring resulting from this cross?

  In some animals, the agouti allele causes individual hairs to have a banded/wq syl1db*k7 mq,82sai k1xefty1w* pattern. The non-agouti allele causes hairs to be a sing2w* sfq qwi8xy1yktal,1 7* e1bdmk/ sle 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 plt8 3t 1oy4n42 n;kmp kv4npwauants was either round or wrinkled. The results of an experimental cross yielded 315 offspring with rpn 144 otkp;akyv83t4 wunn2m ound 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 melanogasterhah v0: j/g2swo.ig;a) have 8 chromosomes. How many chromosomes are in a fertilised oocyte of a fruii 0a;hsh/gv.2owaj : gt fly?

  When does the random orientation of homologous chromosomkn 6n 7z+p pz;o3k7uvye pairs occur?

The majority of the genes in the human genome have already been mapped, meaning dw0wu,x. iqw; the exact locationd .wixu; wqw0,s 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 linked a94rtz2j0yv, ),ogpdfz u p3rgenes?

  The diagram shows a karyogram of a brown male rat (Rattvj d6 obiyj 9).z 6tv+uv7ig*uus norvegicus). Which arrow is pointin 9d oi6tzujiu+jb7 vvy)g*6v.g to a pair of autosomes?

  Mendel observed that there are two poz :nct9 v7u*ocssible variations of flower colour in pea plants, purple aoc7z* :tnu vc9nd white. After a genetic 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 fv-yh 2n+ z 9y*(qdpluprequency of birth weight of children born in London in 1991. up9 y* pz(d qvhn+-y2l

  Which of these traits is an example of continuous variatioa89xgdd2. dwer iem i2;:6j3 gb;xpgbn?

  Which row correctly describes diploid and7u 9dgz 05xfa2 2a:)a6z ozxugk7mg *sm1 rfrs haploid cells in humans?

  The following table shows the diploid chromosome numb h03* vjkpau0ler of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive al,wimls l3 .a-a*xg 7uplele (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 Aqet-kl7 +d qnx 1;t2b, hw wjom.o/gd7 had a child with blood type O. What are the possio w 2dbh1oq j g.neld;7/q-t +ktx,m7wble genotypes of the biological father?

  Which row shows the correct annotation of the alleles for blood grou -8 2i8:/ l8jn0 u cuiz3)zrmgagnwwqgps?

  Which of these statemb nig(w .f.6lg*kmmp2 61vteem ; pbe1ents are true for 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 the spre rrfvo, np+8*dad of malaria across the continent of Africa.rf,*opd8v nr+


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 determined by a numby3p qc(x h/w eb/m8+jyer of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) colourxj3 y8pcyw/( bh/q +me (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 and unlinked genes3 )/8vkvjy 8a y+alppi zqob8a qk.j-4.

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

Sickle cell anaemia is caused by the km2hxocqv:pf9vc7 i c9i ar56*m obdc .5js81 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 brown,a(/1 5 l-i rz3ey:y2 1vins/fonxanus long hair and a female cat that has black, short 3u(izry/n21 if -5 :vxaa/ 1ynoslneshair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), e-:pt w dpadxwl 4p*r2+ m,i/kthe allele for diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) anw*et ldrp+2-pwk :dpim 4 /,xad 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 , owl2 85 a4e,hcjlsv81xt+i 9pawnww(L) is 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 anno e, 9+ix lajtawwp 84hw2w5cv,s1l8d 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 conditic ksf.mgul01 6 dz oo30/kild-m0za3 /*p tcwvon shown in the pedigree chart belo 0c0*.l1lumd06tf zo ps3a omzg/ v/c-3kkidww?

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

  Which of these statements about genetic disorde3ifv5 qw0t.c dullw5* rs 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 distr x8j,yl7jxwfh wl g(-3ibution.

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 dis81m+b va/uvvde (z+yuorder shown in the pedigree chart is X-linked r u mu( dy++z8a1ebvvv/ecessive and not autosomal recessive?

  Different species of living organisms have different numbers o(;ejyx ie4cupj:qo);f genes characteristic to them. The table shows the estimated number of genese; )up 4(j;ceoixjyq: 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 plants, including flower o(r szdc27,g x(o)w 1jgzs8 fxcolour. If the pea plants Mendel was studying can only be white or purple and follow the rules of Mendelian genetixfx1()o ,8 wdogscz7 2 jzr(sgcs, which of these statements was correct?

  A biological male with hemophilia and a biological female without hep;hx0ut)kup8+ fc: uv mophilia have a daughter without hemophilia. What are the possible genotypetp+uk fux)uc8: 0hp;v s of the daughter?

  A dihybrid cross was carried out betwt,nwt4*e8 ko7 d- iys:n lubw-een two sunflower plants (Helianthus annuus) to see if the genes -s8n:eb 4ik u,wt*w t7-yldnofor 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 childacmru- :iwokhf4s zmm)/x2 ,c w4id1/ with blood typercaz m/o1i,sx /)4k24w:fiw md hu-m c O.

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

3.Explain the role of inheritance in genetic diseases.