A man and a woman have a daughter and a son. Their daughter has normal vision, uw( kogg+f3z; but their son is colourblind. Which one of these genotypes could buwfog 3;+g( zke correct for the biological mother?

  Which diagram shows t i)m90g ae6xku5j3ibyhe sex chromosomes of a somatic cell in a human male?

  There are two alleles for flower colour in snapdragong(j7)vztjc2 m s. However, the result of a cross between two heterozygous plants yielded oft( mj2)zcgj7v fspring with three different observed phenotypes, red, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched t go:h6j2wd ui6o the correct definition?

  Which of these statements is a correct definition forg0x40etgd vhht5lamu)9*f r0xzre+, dg )k/s a gene?

  The diagram shows a pair of dmg(i +mv0,cl homologous chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trgiddz k ir54x0 ,bmh++ait, were crossed in an experiment. Which row shows the expected phenotypic ratios of the offspring resultindr5ki4++m, dhxbiz 0 gg from this cross?

  In some animals, the agouti allele causes individual hairs tv06z:ycr*/ kio vdoz) o have a banded pattern. The non-agouti allele causes hairs to be a single colouz zc0o/kyv6ivd*o) r:r. 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 pe ic/patk7e*2 lants was either round or wrinkled. The results of an experimental cross yielded 315 offspring with round seeds and 105 offse/kpe2i c* 7atpring 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 chro 72alls*fm- m *h5srpfmosomes. How many chromosomes are in a fertilised oocyte of a fruit flyrm fas *2-fpm7*h5 lsl?

  When does the random orientaz:ug7ab)f n) br a:7tqtion of homologous chromosome pairs occur?

The majority of the genes in the human genome have already beewo n:p 8.-qinvx r88(7qahhp en mapped, meaning the exact locaorh q 8n8ax7-: q8 (nvpwpehi.tions 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 linoy ,6+r ds (9gt2owtkmeyq97pkw/rc0g13lbb ked genes?

  The diagram shows a karyogram of a broln2y ih:itbc6tj9 z9: wn male rat (Rattus norvegicus). Which arrow is poi 9:ctzth6:bln 2y jii9nting to a pair of autosomes?

  Mendel observed that there aruw:( yz ta2i9.bybc a;e two possible variations of flower colour in pea plants, pu wyzai(2;tu:b by.9carple and 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 frequency r 0a3ii*k4zfbof birth weight of children born in London in 1991. zr 0b*iai4kf3

  Which of these traits is an example nxwsr ,rus27931 oircof continuous variation?

  Which row correctly descriy a/) s.5lv q(q8 sijmudav8)xbes diploid and haploid cells in humans?

  The following table shows the diploid chromosome number oft1urw++v)hym 49ijt w a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive allele ( 4k.xdjp. vyjd1b+zi)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 ai(oifi *47 dutype A had a child with blood type O. What are the possible genotypes of the biological fatheriui(4 7* oidfa?

  Which row shows the correct annotation o9zsfhi,0gghpj:m. .v wv5a;kf the alleles for blood groups?

  Which of these statementbxcsf5 p;dc (6 tjg4q:s 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 spread of malaxcc,+ mpy-e6dria across tdc e,+yxc 6m-phe 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 dete42) zfj iebc8grmined 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 to2ejfb cig8 )4zne (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-7 wybq2+btx8xr 8xtb genes.

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

Sickle cell anaemia reff5 .ghi ms45hr64e is 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 c;qv1yhqbie33eym n6d d,.gw 7 ross between a male cat that is homozygous for brown, long hair and a female cat that has blagnqwe iv6ey,31; bd3md7y hq.ck, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the alw8tc+r z:un1 z-7taqf lele for diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) is domirnzua c:8wq1-z t+7 tfnant 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 qw*6 soeh.5k:f:u*k9 q7 abw0eha+ vna xlor-porcellus), long hair (L) is dominant to short hair (l), and curly hair (C) is dominant to straight hair (c). A test cross was carried out between maleeqk7x-eobh ::kr9hwl 0 nsaaf w.u o5*v +a*q6 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 inheridpes.-v4,h di qt85nttance of the condition shown in the pedigree chart belowidd tp en4ts85,-qvh .?

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

  Which of these statements about genetic disorders is/ared7qy tj:z5zc* q+ae0g 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 sku( i))1yom2l)jdvb z how 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 pedigree charth;5*jt9 oqyf a is X-linked recessive and not autosomal recessij;ft ah*9o yq5ve?

  Different species of living organisms have dif j:)wmx j /kl 44iqcl;eadub9.ferent numbers of genes characteristic to them. The table shows the estimated number of genes for five species. lbw;ju44 x:9ie/.a)jc klm d q
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 characterr bj 0fkfk:)k;istics of pea plants, including flower colour. If the pea plants Mendel was studying can only be white or pu kk;rf0)fjbk: rple and follow the rules of Mendelian genetics, which of these statements was correct?

  A biological male with hemophilia and a biological femalb8lb5x db /-a5d(dicue without hemophilia have a daughter without hemophilia. Wh( dbdalb8- dc5/ 5buxiat are the possible genotypes of the daughter?

  A dihybrid cross was carriedgijhf2q;l-kqv t + .8l out between two sunflower plants (Helianthus 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. T8l ;.tvij+ fqqg2-kl hhe calculated value for the chi-squared test was 10.05; what does this indicate?

1.Explain how parents with blood type A and(m qd;sd/ ,pqjs fo*h* blood type B can have a child with blood (poj, mdq sq;d**hs/f type O.

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

3.Explain the role of inheritance in genetic diseases.