A man and a woman have a daughter and a son. Their daughter has norm87p*drt0k;cd +ix q goal vision, but their son is colourbli; c d*08go qi7ptkd+rxnd. Which one of these genotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic cel;;usz8 pqzxthd 0q09 el in a human male?

  There are two alleles for flowevj2*m, amqzoha2nzv/ ;+ h oh,r 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 explanat/azv,v + h;qmh ,o*2jmah2zo nion for this observation?

  Which keyword is matched to the correct definf2fx) rv(h4uoition?

  Which of these statements is a corre wv 6ll1b: dp49ya2agpct definition for a gene?

  The diagram shows a pairtkn1)s:1 o peeho;c k/ of homologous chromosomes.

How many loci are shown?

  Two individuals, heterozygou ( 5p03ghx e3k 4/xsqebpaupg)s for a specific trait, were crossed in an experiment. Which row shows the expected phenotypic ratios of the offspring resulting from3qg x43pb ph guea()xsp0k5/e this cross?

  In some animals, the agouti allele causes individual hairs to have cy gc t9tjkr+em5tru 0jbr2 t (*pkywj-02p,5a banded pattern. The non-agouti aepu0 ,y(-w jy0*jt k+rbt t5c29mtrj r5p2 kcgllele 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 ijjdrfvy6q9m .e )mz31n individual pea plants was either round or wrinkled. The results of an experimental cross yielded 315 offspring w 1dyv) mjqmjfrz6.9e3ith 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 lk,t+c4ykvk.j) v wu9) have 8 chromosomes. How many chromosomes are in a fertilised oocyte of a fruit flyk y,wc 4.v9u)vlk k+tj?

  When does the random orientation of homolo947h uk i3 vov(mctmt(+ urk*bgous chromosome pairs occur?

The majority of the genes in the human genome have already been mappec.;.a pbu ve vb*3msts3.w q0jd, meaning the exact locations of the genes on chromosomes are known. The diagram 0 wqm as*. jc.bb3v3 .;pvtsuebelow 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 linivl 6gpv6m adf//rw, pf4zz3j8z 1:qhked genes?

  The diagram shows a karyogram of a brown male rat (Rathb k6p t9x *srwf74:g*ev nx/gqk x/h)tus norvegicus). Which arrow is poi fhgq 9/: kxn4*6h)wxep kt/r*xvbg7 snting to a pair of autosomes?

  Mendel observed that there are two possible va iberj, a*k /0w 5hp/1no.wpmuriations of flower colour in pea plants, purple and white. After a genetic cross, the ratio of plants with purple flowers to white flowers is 1:1. What were jp1wwk ne*,/r.imhb/op u5a0 the genotypes of the parents?

  The graph shows the frequency of birth weight of children born in Lm3csvo4o8 n69skrv)v ondon in 1991c4ko3rm v8v)on69sv s .

  Which of these traits is an example ofikl28 ciyic7 7 continuous variation?

  Which row correctly describes diploid and haploid cellssh; h04/h sgke in humans?

  The following table shows iom 9z3(gq m1dthe diploid chromosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused b;d5(wb6wx q- e49pklte r u9vm*vsv hb1-toj3y 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 type O. What aregwm tnquu -6jdpwwcr *lt06(g02xum -4w c5 ,r the possible 526- *n ctjqpctw06dg mml ,ruw 0wu4 rxg-(wugenotypes of the biological father?

  Which row shows the correct annotation of the alleles for blood d sw/:/ .rhy;nn5 gemcgroups?

  Which of these statements are true for d85m7cd)5k4dr y mmtc 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 acrtwmw: 1fs ,d 2bqtc2a8oss the conm:bw2wdtf8 1 qs t,ac2tinent 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 przewal( eu , og,o.)8)g;z5hd9ywfo zu3yl bah-k mulskii), fur colour is determined by a number of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre h e)go,uwh -f(.;l9u,yuk 58bzoga zymld )o3 (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 unliu glf0 4i*kdyp fj:hpak7e+r(u* p* 1znked genes.

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

Sickle cell anaemia is 7mngd/*n,/i4cs1zi:n 2csg tq czsf )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 betwee2jq*9: )( ttgf n0bog ,qzewpgga)* shn a male cat that is homozygous for brown, long hair and a female cat that has black, short hair.g bpoft)ggg2):e,hqs* jqn(t09* wza


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxaculz+mo-3n -x7w(ke/ oznin+q um officinale), the allele for diamond-shaped seeds (D) is dominant over ovalkznznoxn( 7 3l+miq uow -/+e--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) is dominant to short hair (l),u2 9*spau/;eawv9q4k cdkm 8k 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 (q9ukdp e9wv28mck sa; / ak*4uχ2) 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 -t2:df.hm r/ aps.kw 8q6pnnj condition shown in the pedigree chart below? fpj-thn m2dw:pk ar.. n/6sq8

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

  Which of these statements about lmx2 az jnq bn3/+i9c6genetic disorders 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 can show a normal distribut(d0 lhddv+ +p dx.l1yrion.

2.Outline the differences and similarities between homologous chromosomes.

3.Explain why expected and observed Mendelian ratios may differ.

  What suggests that the in+ e38d xtgd+oyzufo3 :heritance of the disorder shown in the pedigree chart is X-linked recessive and not autosom3:3oofz+ 8dyt gedx +ual recessive?

  Different species of living organisms have different numbers or6ypqbok;v3618xgt y f genes characteristic to them. The table shows the estimated number of genes for five speciesyt b6rg; v y63pxk18oq.
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 characterist+v-uzk3*qosl :fe t4c ics of pea plants, including flower colour. If the pea plants Mendel was studying can only be white or purple and follow the rules of Mendelian genetics, which of these statemenk4e vou:*-+l3t fczs qts was correct?

  A biological male with hemophilia and a biological female withibg7 wodn42r* out hemophilia have a daughter without hemophi*7i 2rgon b4dwlia. What are the possible genotypes of the daughter?

  A dihybrid cross was carried out between two sunflower pla piltk9ft 7qd724im /lnts (Helianthus annuus) to see if theilqtt 4dm p92i7l7k/f 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 with blood type A and blood type B can have aro8 9p z;.wbuu child with blood type.8b9 p zrwo;uu O.

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

3.Explain the role of inheritance in genetic diseases.