A man and a woman have a daughter and a son. Their xcknp90; +h-pt c( luxdaughter has normal vision, but their son is cxutc+cplkp;x 9 0- (hnolourblind. Which one of these genotypes could be correct for the biological mother?

  Which diagram shows the sex n *ubv-+l g.ca39 b5jfulv*hnchromosomes of a somatic cell in a human male?

  There are two alleles fo, hj-li+kri owf-z r;hh02w;zr flower colour in snapdragons. However, the result of a cross between two heterozygous plants yielded offspring with three different observzr;2fhw ljhki;r +o z-wi,-h0 ed phenotypes, red, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to:z,; pen nxgnr8 ixil07eist o(,a8e0 the correct definition?

  Which of these statements is 4hefvx/t.j h0 d+p4d wlv wv4*a correct definition for a gene?

  The diagram shows a pair of homologous chromosnbcrqx; msk 09mdu/c. 29 4kwhomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were crossed in amr ox,81n) 8j*fh psjon experiment. Which row shows the expected phenotypic ratns,hj 8fm8 xpo1j)ro* ios of the offspring resulting from this cross?

  In some animals, the agouti allele causes individual hairs to hcgc9,y)- b niuave a banded pattern. The non-agouti allele causes hairs t,cg bcn9u-iy )o 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 seer60mmfeh36me5vq d 7 ub e/c +8zksyc1d shape in individual pea plants was either round or wrinkled. The results of an experimental cross yielded 315 offspring with round seeds and 105 offsprink5y76m0/rc+heecubm 1feqm63 z vds8 g with wrinkled seeds.

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

  Neurons of the fruit fly (Drosophila melanogaster) have 8 chromosomes. How many 4l*uu4w(imdex 5,axsc u ,5wxaldm ei4s*(4uxhromosomes are in a fertilised oocyte of a fruit fly?

  When does the random orientation of ho5j* h*qjaxl1t mologous chromosome pairs occur?

The majority of the genes in the human genome have already been mapped, meaning*.a9gy kn1)(d hsazvj the exact locationyg. sk(1hdz a9ja )n*vs 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 genes?ud3 h;vak y9l/iq 3.nk

  The diagram shows a karyogram of a brown male rat (Ratj)*wbww 71a-gf) c/ppimb,tl tus norvegicus). Which arrow is pointing to a pair of autosob, fg7/cj1) b*-it )wpwmpalw mes?

  Mendel observed that there are two possible variations of flower colour in pea p ;-45m*basm0r-twk;3nsft/gvkf i vp lants, purple and white. After a genetic cross, the ratio of plants with purple flowers to white flowers is 1:1.m;4r/ms ;vf- na5bfkp t0w v-i*k3gst What were the genotypes of the parents?

  The graph shows the frequency of birth weight of children en,+wjw r-4 .mt 3a.wpkv3sso born in London in 1991.k rsw .v .m -3pjosenww,at4+3

  Which of these traits is an example of continuous varia*f/b4 zs9ru2v sltn sb)h-ln 8tion?

  Which row correctly describes dipljw 5qc7b m*q:toid and haploid cells in humans?

  The following table shows the diploid chromosome t6e 6 zc-v 7pg/*d e:hbpj5o.q+bgfeanumber of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caus; scll4 fu1q8mei1 sw;bel : y-osf-j;ed 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 blood type A had a child with blood oj/emnb(.r0 ctype O. What are the possibl.rmo en/cj0b (e genotypes of the biological father?

  Which row shows the correct annotation of:an.jo8i;n 4lit6 cy u the alleles for blood groups?

  Which of these statements are sk-2g6r ofi6utrue 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 sik)qg ny 9u-e/paf)2j ickle cell anaemia and the spread of malaria across thjnguk-) 9 ipfqe2a)/y e 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 determined by a number ohtj9x s,e2,xif genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) ,t,xehx9 ij2s 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 and unlinked g 1n/x5l o)gg-q*o.f vx/u dibbenes.

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

Sickle cell anaemia is caused by:de -i)4i :8v7 i 1k,jmthj9u;efsffka-way m 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 cat that is q- :7g oy*y,omzfo3mm homozygous for brown, loo,my fom* y:zm-7oq 3gng hair and a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamond-shaped seeda.aocb *,+,s jjfd 7rbs (D) is dominant over oval-shaped seeds (d) and the allele for rjo,,dsjb7* abf.+a c 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) is dominant to s.tg5ge i 4k3nhhort 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 sh ei3ht45g.kgn ort, 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 ci.tvgc5 qs w 0wwb5l/n9rb*/zondition shown in the pedigree chart *qc0rvwzbg nsbw.59l 5iw / /tbelow?

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

  Which of these statements about genetic disojdt6ppy,m7jp a sp64 7rders 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 tr wsa:(;wj+kb7nao:2. egc z ekaits 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 inheritance of the disorder shown in the pedx5rcx7x/ehs g*h --y uigree chart is X-linked recessive and not autosomal recessxexs-ryc5 uh* 7xg /-hive?

  Different species of living organisms have different numbers of gegokt, de;gf( s7jn9cvoj)9 v1 nes characteristic to k sctd),jo9;vjo1vfn79 g (gethem. 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 characteristics of pea plants, including flowenwsfarlls962/su 9u/r colour. If the pea plants Mendel was studying can only be white or purple and follow the rules ofuwl6ua l/s/9n s92sf r Mendelian genetics, which of these statements was correct?

  A biological male with heykkknbt7 t-egr5. . u,mophilia and a biological female without hemophilia have a daughter wit.5.ut-tkerb , g7kknyhout hemophilia. What are the possible genotypes of the daughter?

  A dihybrid cross was carried out between two sunflower plants (Helianthus annuus/ )lw zvgp kk5,dmo*4y) 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 kv*myd z5/w)o,l g4p klevel was 7.82. The calculated value for the chi-squared test was 10.05; what does this indicate?

1.Explain how parents with fg5szr l k/-wwxen(00blood type A and blood type B can have a child with blood type 0k(l5xwsew- gr/0 zfn O.

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

3.Explain the role of inheritance in genetic diseases.