A man and a woman have a daughter and a son. Their daughter has nh u2vn )l2 mqy(*jgqe;ormal vision, but their son is colourblind. Which one of these genotypes could be correct for the biologe) qn; *hqm(ju2vgl2yical mother?

  Which diagram shows the sex chromosomes of a somatic cell in a hum19op/uonbodc6b/g5v an male?

  There are two alleles for flower colour in snapdragons. However, th4(y27vu,qy(lmjfb r x51mc jce result of a cross bet7j 1cl(y vqxcj br2ym5,m(u 4fween two heterozygous plants yielded offspring with three different observed phenotypes, red, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to the correcl/75pd vyrmyesh2* /y0gll; qt definition?

  Which of these statements is a correct definition for a g6klx,znp k:- -+gfw ezene?

  The diagram shows a pairf/ej ail-z2/f ;a8qf 0z*vfs i of homologous chromosomes.

How many loci are shown?

  Two individuals, heterozygou: h)x3*q lmeias for a specific trait, were crossed in an experiment. Which )qx3mhl * eai:row shows the expected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti allele causes individual hairs to have a xnarqj7gne4 .+6s+ pk banded pattern. The non-agouti allele causes hairs to be a single col n6r.gaq+ p+sxnj 47ekour. 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 plann;wb 6btk*mw2ts was either round or wrinkled. The results of an experimental cross yielded 315 offspring with round seeds and 105 offspring with wrinkleb*k26wnbm ; twd seeds.

Which row in the table below states the most likely genotypes of the parents?

  Neurons of the fruit fly (Drosophila melanogaster)evhx i )*hg/3y2j ns9w u7wr7b have 8 chromosomes. How many chre3wjb sh ) 79/whuxin*2grvy 7omosomes are in a fertilised oocyte of a fruit fly?

  When does the random orientation of homologous chromosome pairs ocxojf c375t/u qcur?

The majority of the genes in the human genome have already been mappm3. wb+xt un-bki)9bled, meaning the exact locations of the genes on chromosomes are known. The diagram below .mx-kbtu9l)b i nb+w3 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 def o7mpsj/6+jf s n.k,qzinition of linked genes?

  The diagram shows a karyogram of a brown male rat (Rattus norvegicus). Why i8v0l awq*wt* q*v(mich arrow is pointing to a pair of autosqmvyv0*iw8wqt l **a (omes?

  Mendel observed that theg-pmv-b w5r9hxzoi h801t kr 3re are two possible variations of flower colour in pea plants, purple and white. After a genetic cross, the ra hz k m081vpo-bh5rrxi- 3w9tgtio 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 chivfpgs; kl wag06on589 ldren born in London in 19910ka8;p6lg s9vfn5ogw.

  Which of these traits is an example of continuous variation/ zic53sz 50ol+y, su7ntqk:wup ,xq g?

  Which row correctly describes diploid and d, 5bh3fe elpn,nb:t, /avde3haploid cells in humans?

  The following table shows the diploid chromosome number e :(yx2lt;fcf of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is causd9 b,fcgb+ah4dls w-(ed by 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 -c2jh/+z 6znk 7k4t;f/ nya)tzokujdtype A had a child with blood type O. What are the possible n)yz;k jk2u+/4th n/-ftoz 7a6dzc jkgenotypes of the biological father?

  Which row shows the correct annotatiowuu)::yr(va.i r npdg 1sqn*4 n of the alleles for blood groups?

  Which of these statements a si dvnl3x -xef((/m5 /qoy4hzxm/. v1jgcgz)re 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 sicksge-o g; -/*(qro b8vcrk)j3ndk r,qyle cell anaemia and the spread of malaria across the continent of Afo gqj y3rdoqe8 /,*b;kvn) (rs-crg- krica.


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 determig 15qhsuwljbasc dk61n)9n : 6ei6v(e t++nained by a number of genes. Brown colour (B) is(s9ai)61 1eu 56l6c+ k nthibdvngqwjeasn+: 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 betweey59ttes:0af9tdc p , pn linked and unlinked genes.

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

Sickle cell anaemia is cau*a-2 qitqj b:ado:.tysed 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 is homozygouset+-zbyld:n 9i7jyp1 14d 1:ledegbi for brown, long hair and a female cat that has e- iyd1 gbby7 p :1zjl:9tn+ldd1 e4eiblack, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), tggpml).3 9d fhn:- brrhe allele for diamond-shaped seeds (D) is dominant over oval-shaped sebghrng-ld m f 9.r)3:peds (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;w ind64abn-n fk i nm-(/)fzk), 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 male heterozygous long, curly-haired guinea pigs znkn-bw(f;6n/n f-diim) 4 ak 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 ijj;/ *(z:qqsvkcmdve l; k a(5nheritance of the condition shown in the pedigree chart below? az;jv(lsmv;k/k* q(q: ed5cj

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

  Which of these statemen;vi:3gzvc c a9cy ,gh3ts about genetic 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 normag zliwa9) w; 3fasn.8dl 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 w(luw ::kq3w )8j wlcxof the disorder shown in the pedigree chart is X-linked recessiwqw3w:lw(xju: k8 )lcve and not autosomal recessive?

  Different species of living organisms have different 8)9dv o3bxmvrnumbers of genes characteristic3)m d9vxvobr8 to them. The table shows the 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 pea plants, including flower colourfd5. nozo87y xoy;xq.n7 t3e d. 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 correct7nxtzyyo ;o7 d on 5d8.efx.3q?

  A biological male with hemopjb9vosi ,s1u,n tj9/p 9gzi6yhilia and a biological female without hemophilia have a daughter withouti bp/yg uzvo9s,9ji,s61j9tn hemophilia. What are the possible genotypes of the daughter?

  A dihybrid cross was carried out between two sunflower plants (Helianthus annu u/4e7p;l2 ftp-woh b*oscj:cus) 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 calculated value for the chi-squared test was 10.05; what does thib/fcs * 72-l:h4 jpot;co wueps indicate?

1.Explain how parents with blood typ,*b7e t nhru0ce A and blood type B can have a child with blood type O. 07bec rt,nu*h

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

3.Explain the role of inheritance in genetic diseases.