A man and a woman have a daughter and a son. Their daughter has normal vision8kv+hl7ak.fo+cxw caj q..,r, but their son is colourblind. Which one of these genotypes could be correct for the ba+f ,vr lo8c a.q.wh7xj.ck k+iological mother?

  Which diagram shows the sex chromosomes of a somatic cell in a human male? en5r 7m+xlt5u

  There are two alleles for flower colour in snapdragons. However, the result oi9( dyez;hc0iv4g cdx02ap3o f a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red, white and pink flowers. Which is the most likely explanation fic d( 39hy0p0gx;vceo4da2zior this observation?

  Which keyword is matj1befu3 3vncj o.8ik;ched to the correct definition?

  Which of these statement cz0s 0ehjn8bs(+h4 .w +vdh9m).zwmve)lryes is a correct definition for a gene?

  The diagram shows a pair of homolo -jx*efwgi4syyg:;z/gous chromosomes.

How many loci are shown?

  Two individuals, heterozygous for adfva 2cg4mkq, ci*+0w specific trait, were crossed in an experiment. Which row shows the expected phenotypic ram20gwc*af+ kd i,4vqc tios of the offspring resulting from this cross?

  In some animals, the agouti allele causes individual hairs to have a b s*od cs5.yi4j74s.gof m kcq/anded pattern o.ksqc jf7* ygc4md /o45iss.. The 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 kro0 p sjf-xump2xqf(6r :;m :seed shape in individual pea plants was either round orsp xm:p qkxmfru20jo;( f:-r6 wrinkled. The results of 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 (Drosophila melanogaster) have 8 chromow:nnh 77g)uczsomes. How many chromosomes are in a fertilised oocyte chngu:n 7 wz)7of a fruit fly?

  When does the random orientation of homcxwmllko*f,(1 2y2xa ologous chromosome pairs occur?

The majority of the genes in the human genome have avd:ew ;qa v)y9lready been mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one representation of a homologous pair of chro;:eaw) vd9vyqmosomes.

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 ge8;1ntkcadc k, ,of fg0;xq1h pnes?

  The diagram shows a ka1 7b)h jy: g:ov;uuxdhryogram of a brown male rat (Rattus norvegicus). Which arrow is pointing to a pair of j:7hy ugu; b)1:odhvxautosomes?

  Mendel observed that there are m/ a)oni 4kvo4 c aeuz+q+z)h+two possible variations of flower colour in pea plants, purple and white. After a genetic cro/ )4zev +cquoa+na 4io hm+z)kss, 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 chil 47j+ojz/mraf dren born in London in 1991.z4a/fjjr7+mo

  Which of these traits is an example of continuous variation?z)8hdgz;1f wfz ennhe 950jer (s1t7x

  Which row correctly describes diploid and haploid cells imc-.kz. +cqki5zu-r in humans?

  The following table shows the dip. .j:m gu os70tuohbg9loid chromosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive allele ul ,/b+uf c0ezu/ l*dv(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 chiii1/.39 umj4uk obt(2kzq o1//rja,f i kqqauld with blood type O. What are the possible genoty9q1 qb/uzii3i 1o /kakofa/ur, (. j 2jkutqm4pes of the biological father?

  Which row shows the correct annotation of the alleles for bloohbf t (yl443w*huf,m qfx w 594csted5d groups?

  Which of these statements are true for 70z4e . 2 8cxnbssdy4w zzeou,li e9.ualleles?
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 acr 8-7 .rn5c+rwev lr0y inennp2oss the continent of Africa.+ e 8rpn57nrcvy0el -wnnri2.


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 nugkm;2s8shap rj 1 m58/ yoaax0mber of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) colour (P) is dominant to one m10y 8 /o;psg5 xhjsam8kara 2tone (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 unlmm83gi j (on*k6(izrxinked genes.

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

Sickle cell anaemia is caused by thejev0s .,g39 jxiqs2k9) elvokb m6j5y 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 homozygou nkp8e:+gviz-s for brown, long hair and a female cat that has b+zenvg k- ip8:lack, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allerls4tsvo u, g+bi1 p4:le for diamond-shaped seeds (D) isr4glt1:soi vb+pus4 , dominant over 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 k*3;dihk st n d7:,fvl(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 and female short, straight-haired guinea pigs and a chi-squared test (χ2) was carried out onn 7ksivd; :,3k*fh ltd 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 con8 .9 djvaxj0imdition shown in the pedigree chart below 9.aj8m0vjx id?

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

  Which of these statements about genetic disorders is/are cmse f7(7 a6wqxorrect?

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 ahg:x:2xfl1bnq(n dns9vwb*h;mk :1a 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 ;+v(l v wg-yyp0n im5xiew vy1+uil07 chart is X-linked recessive and not autosoma ii xuiewy0p5 vlv0y 7lm-y;n (wgv+1+l recessive?

  Different species of living organisi*il5xx 5k0x/je7ootqf4 )a tg adm 40ms have different numbers of genes characteristic to them. The table shows the estimated number of genes for fiv4)itat*q o k7 ai0/m4o5e0jgdlxxx5f e 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 charactelkyevq2ow/ 3/ ristics of pea plants, including flower colour. If the pea plants Mendel was studying can only be white or purple and follow the rules oqlywe2v//3k of Mendelian genetics, which of these statements was correct?

  A biological male with hemophilia and 76 g zrtfdzh zokj/53,zz8n6ua biological female without hemophilia have a daughter without hemophilia. What are the possible genotypes of the daughte 6ng3ko rzz6z,hz7tfj85/dzu r?

  A dihybrid cross was carried out between two sunflower plants (Helidxf +2ltg *1epanthus 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. The gf +1*d lpxe2tcalculated value for the chi-squared test was 10.05; what does this indicate?

1.Explain how parents with blood type A and blood typec;l ez1l gb/ezgxx jf0/+.+pkjcb e;) B can have a child with blo )zgbece;el/ k+p/clxj;gf j1+bx z 0.od type O.

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

3.Explain the role of inheritance in genetic diseases.