A man and a woman have a daughter and a son. Their dv 9-jv*r7o+yt f dl3fdaughter has normal vision, but their son is colourblind. Which ondf-l y9fvj3v+* r ot7de of these genotypes could be correct for the biological mother?

  Which diagram shows the sev :kq 6,ubvg(px chromosomes of a somatic cell in a human male?

  There are two alleles for flower colour in snapdragons. However, the rh,l)zole 9 bj78e fdtox(xw07esult of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red, white and pink flowers. Which is the mowh(9oz, 7fo)7dxbel elj80xtst likely explanation for this observation?

  Which keyword is matched to the ci;ag+h iut :-correct definition?

  Which of these statements is a correct definition for a gened pn8ah+z4,t r?

  The diagram shows a pair of homologous9qtz t:2(pmmw s*:c im chromosomes.

How many loci are shown?

  Two individuals, hetertn9xy s;(v.g; y,vayuozygous for a specific trait, were crossed in an experiment. Which row shows the expected phenotypic ratios of the offspring,yu y vgy;.s;9avx(nt resulting from this cross?

  In some animals, the agouti allele causes individual h 0ue dcn7odmol)w 7i5/airs to have a banded pattern. i7 75lo udn)d0/emwocThe non-agouti allele causes hairs to 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 seed shape in individual pea plants;cld;4 nhcej: was either round or wrinkled. The results of an experimental cross yielded 315 offsj d;e l4cc:;nhpring with round 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 melanogak1x iu)9 8jjem3g ekm5ster) have 8 chromosomes. How many chromosomes are in a fertilised oocyte of a feei58gk u) 9j x3jmm1kruit fly?

  When does the random orientation of homologous chromosome pairs occurvw/ce1:b h g,wn0eur2?

The majority of the genes in the humako)h j f(e0lkgq4 t9op2ey e57n genome have already been mapped, meaning the exact locations of the genes on chromosomeoq)4( h9ye5f 2kl op0jtg7 eeks 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 definity 1m+5 biji)ivfhduv5)p: 2xk ion of linked genes?

  The diagram shows a karyogram of a brown male rat (-c ef fe za0v6(8z4hjvRattus norvegicus). Which arrow ise c8az -ffz0v4e(6 jvh pointing to a pair of autosomes?

  Mendel observed that there are two p2 ncwus9 j5(kcossible variations of flower colour in pea plants, purple and white. After a genetic cross, the ratio of plants with purple flowers to whi2swnc9 c5u(j kte flowers is 1:1. What were the genotypes of the parents?

  The graph shows the frequency of birth weight of chi ij -afawf+ s.s,(n hz-cp68qoldren born in London in 1991.zh,fnw+ j cf iop-- 6a(q8.ssa

  Which of these traits is an example of cv8 u:fy7zu :icontinuous variation?

  Which row correctly describes diploid and ww,f:ksfl/ z-cc, (k.lrmjs -haploid cells in humans?

  The following table shows the diploid chromosome number of a range of s*f1e1 ox1h3 v-ep ihqbpecies.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive /3vqmytcj *zy(*q nv .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 tyxaa31a4 na e+fpe A had a child with blood type O. What are the possible genotypes of the binaaxafa4 3 +1eological father?

  Which row shows the correct5 mb6po j3f)7s8p*ayealcv7 bfyh,h0 annotation of the alleles for blood groups?

  Which of these statements are true for3uny )v g+uqaew , gq4,20twuv-g*siy 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 spread of malaria a/.rccb mep0 l4cross the continent of Afri.lpeb4c/0 rm cca.


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 det ql0kyu,5z,hz h t9d-iuqr0( sermined by a number of genes. Brown c(0 -i uruy ,kzd,5hq9t0lqhz solour (B) is dominant 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 and unjj.* j q(vc- mncm6:zxlinked genes.

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

Sickle cell anaemia isv+ kgw,q 9yvl: caused 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 cat that q;6* 8gskjs.6obbmh5zr l3kr* /fhxp is homozygous for brown, long hair anhqzfr.8o5sbg*/hp6 j 36 *;kbklxsm r d a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), tv i;e 1icmp9n8he allele for diamond-shaped seeds (D) is dominant overpi n v19;ime8c 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)7tz 9gv5m +:sfrz 4hqj is dominant to short hair (l), and curly hair (C) is dominant to straight hair (c).t qz9 4r7j5h v:fzsmg+ A test cross was carried 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 in the pedigree char* iz,gjicc ;5yt beliicg,*5y j;c zow?

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

  Which of these statements about genetic disorders i(de-tte+ 9hua s/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 t*dvq s x )trt9m7i6g;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 inhere q6nffbvi14: cc c9j*nlt2w/ itance of the disorder shown in the pedigree chart is X-linked recessive and not autoscv62w1n :/c fq4jib9n c*t fleomal recessive?

  Different species of living organisms have different numbers of genes chars n*lz5/7 n przse 6e*az0ryn+acteristic to them. The table shows e z7n nae065rrss*+pn z*/zylthe 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 peai+vzqps0j+u -x q;h *b:;ymjq plants, including flower colour. If the pea plants Mendel was studying can only be white or purple and follow the rules of Mendelian genetqsvq+:u zb x p +qjmji*h;0;-yics, which of these statements was correct?

  A biological male with hemophilia and a biological female without hgur2uok77c ;x emophilia have a daughter without hemogkcru7o u;x7 2philia. What are the possible genotypes of the daughter?

  A dihybrid cross was carried out between two sunfloc-cyl4 ( --e(5t7aea2xwrut dk -kjgpwer plants (Helianthus annuus) twrackp5gk(-tdy jul t(2ac-- x7e 4e-o 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 w/6.5qhdskqv bith blood type A and blood type B can have a child with blood type O.b5k qq/6sdvh.

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

3.Explain the role of inheritance in genetic diseases.