A man and a woman have a daughter and a son. Their daughter has normal vision, +*e;/ 3:l + u0auahyyugprmxybut their son is colough xm:u+pu yya30ul*;r+ /ye arblind. Which one of these genotypes could be correct for the biological mother?

  Which diagram shows the sex vb0 s, w xus.eb,+9cbuchromosomes of a somatic cell in a human male?

  There are two alleles for flosm io3*:1ilv:t11 gir j 7pv0oo5hrzdwer colour in snapdragons. However, the 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 explanation for 1 0:sog 3ii*7iz: 1 oo1djhvtr5 lvmrpthis observation?

  Which keyword is matched to the correct dc4t akv)kp zv2va +7c3efinition?

  Which of these statemt 1ri *.l1lau+n8ymqeents is a correct definition for a gene?

  The diagram shows a pair of homologous chromoso gds .kn6lo3ybm 0iim a2n0*v9mes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait gr;-f: b+8m jy8k0mobvz;c ir, were crossed in an experiment. Which row shows the expected phenotypic ratios of the offspring resulting from o;-jy;b0:m vbf8r8m ik+c grzthis cross?

  In some animals, the agouti allele causes individual hairnakg*m q.ri;: d20evhs to have a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who are heterozygous have hairs with a b*eiqgahn:rkdv2 0.;m anded 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 rou hl/1ip ;p c5u;m8 yzs 9iheqwtx0;4hqix -o3dnd or wrinkled. The results oi 9 yi;om /0q4dzxlxip5uh;1;p 8tswh -e3qhcf an experimental cross yielded 315 offspring 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 (Drosophioivcn 3w+8ogv:u iu (b(2wnd9la melanogaster) have 8 chromosomes. How many chromosomes are in a fertilised oocyn o9w 8+:3in uwv(gdcvi2 o(bute of a fruit fly?

  When does the random orientation of hoe5sa1 e1ydjkr 0rog7; mologous chromosome pairs occur?

The majority of the genes igkf)yii/lnny 86i e3avl7 v-(n the human genome have already been mapped, meaning the exact locations of tvkngiy6 e/(yalv-i nl 7f38i)he 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:kk.j c 1khe*j?

  The diagram shows a karyogram of a broqcgm7vk mf nm :0esf1on+0;j //fdrs0 wn male rat (Rattus norvegicus). Which arrow is pointing to a pair of autosomem0mf:fq s/0 knjefr ms+1;n 0vocgd7 /s?

  Mendel observed that there are two possible variations of flower colour in ;- rtw)u5qpve .yx8cdpea plants, purple and white. After a genetic crosue crp)d;.-5t8vyqxw s, 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 of birth weight of children born in Lonupun 3pjk:)j* don in 1991. *u k:jnu3pj)p

  Which of these traits is an example of continuous varhd:hoi * 7v.rriation?

  Which row correctly describes diploid and haploid cells in humanp e9;,m2c7l 8xoi 2pjao(4apgfn8 iwt s?

  The following table shows the diploid chromosome number of azx;d0o8*2ksniwyi8m 3 u6p ya range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessi69 285-six88 atvllp zxr aqeyve 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 bloo xx-78v 0hu0egk3emydd type O. What are the possible genotypes ov0xmxu-y e g 80ked3h7f the biological father?

  Which row shows the corrl2sr6a48inn(e jbyg m-q( ji5ect annotation of the alleles for blood groups?

  Which of these statements are true for alleles? ydv;+7t9kclvbg l3tz3syxk5 t, l t) :ck2gl )
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 i6h .ohh(( b4wbac; nd;t tcs-the spread of malaria across d tc a.obi-s6c(;w4 hhbhn;(tthe 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 oghq;8fn 79r 4ydsf3 eis determined by a number of genes. Brown colour (B) is dominant to sandy colour (b) s;ny497 fgfqh e3or8dand 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 unlink3doay8;y.xjl vrq-6o2 q ,tei ed genes.

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

Sickle cell anaemia is caused by they ygn5 ar9dda/,wx0ch -jo+2f 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 brow1g+f7j.azfruyug vowp kcus0x6y(,x+mt 5- (n, long hair and a female cat v 5gu (yjtx6ak.1prswxfoc +y+ug7 -m0z(fu, that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamond-seexs.m1 :2cc vhaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) is e:e1xmcvs 2. cdominant 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 short hair 8h/anhie6k y5 (l), and curly hair (C) is dominant to straight hair (c). A tes5 6/kinye a8hht 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 of8 m )h4z)ysjqr,nxc7w the condition shown in the pedigree chart b ,mc n8zyh7w)4xs)rqjelow?

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

  Which of these statements about genetic disorv tdj1 :4dhu+ce+kl 6tders 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 :dp1dhoh j/ - ( h9(z6 gbehb(qvyxb)ecan 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 inheri0y- c ggct scr1g)nx/+ swl2m.tance of the disorder shown in the pedigree chart is X-linked recesxy+cs rm s t/.0lg1)gcn 2wc-gsive and not autosomal recessive?

  Different species of living organisms have diffe i6g3xbea9 wry61qt/ erent numbers of genes characteristic to them. The table shows the estimated number of gen6b 9r/16qgxiay 3ewet es 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 coloy7h79v 8 tr* cf3wi g5dxqg++kan j8iiur. If the pea plants Mendel was studying can only be white or purple and follow the rules of Mendelian genetics, which of these statements was cog5n wy8aktfi 7i37xh*grid98jq c+ +v rrect?

  A biological male with hemophilia and a biological female without hemtd3(ezyjb gr(9* ;k goophilia have a daughter without hemophilia. What are the possible genotdt eog3*j9kz(;ygr( bypes of the daughter?

  A dihybrid cross was carried out between two sunflower;udado (,f 8jctzb p+: plants (Helianthus annuus) to see if the genes fpb zto:a(f8cd d+; ,juor 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 child wity;i (oxp8j xx8h blood type O8xj 8yx o;xp(i.

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

3.Explain the role of inheritance in genetic diseases.