A man and a woman have a dn)rz g r4f) vs;7)fjjnqv21uoaughter and a son. Their daughter has normal vision, but their son is f;sng)ojj vrr)2nu7v)f q1z4 colourblind. Which one of these genotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic cell in a huma1/4i 5 csej72*j pzjtux(r xpwn male?

  There are two alleles for flower colour in snapdragons. However, the resuojbc05pi)c x6 guz h1.lt of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red, white and pink flowerh zi b0p1 5jgcxc.6o)us. Which is the most likely explanation for this observation?

  Which keyword is matched to the correcth99 (oilaj .end7l- mb definition?

  Which of these statements is a correct def/-r7u fhb7cxj5mdat 9inition for a gene?

  The diagram shows a pair of homologous chf vfphlm7;9h +v6d+yzromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were xyl36 kde6w5vcrossed in an experiment. Which row shows the expected phenotypic ratioelv5dx w k63y6s of the offspring resulting from this cross?

  In some animals, the agouti allele causes indpd) 3swwa6ok(filo l;tsy31 2ividual hairs to have a banded pattern. The non-agouti allele causes hairs to be a single colour.ow l;3ftyk2l36 wis)d op(1s a 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 plauv n ns+m.9s4wnts was either round or wrinkled. The results of an experimental cross yielded 315 offspring with round sesnu9sw v.mn+4eds 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 chromosuwa rou716ya0 m60xgbomes. How many chromosb6u6 7y a 1omg0xuwra0omes are in a fertilised oocyte of a fruit fly?

  When does the random orientation of homologous chromosomec. 2sr(xu5mpc-uwx8i pairs occur?

The majority of the genes in the human genome have already been mapped, meanina r8cvbh*:,b ng the exact locations of the genes on chromosomes are known. The diagram below shows one b:rn*ca, 8vhbrepresentation 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 defini7mb(d d p75b+fc :mfqstion of linked genes?

  The diagram shows a karyogram of a brown male rat (Rattus norvegicus). Which arr,q vz+u 4oezy2ow is pointing to a pair of autosom vzoq42e ,+yzues?

  Mendel observed that there are two possible variatoz(rrk9jcu 4 a:s 6ba2ions 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 the genotypes of the parena:jz92u4ka(b rro 6scts?

  The graph shows the frequency -;hhrraff f s- ;p*;yvof birth weight of children born in London in 1991fsrp;- vfhr- yha;f*; .

  Which of these traits is an example of continuous variat0gxlwez;, 5 tgion?

  Which row correctly describes diploid and haploid cells in 4 us0n gi2f8(wld.ce whumans?

  The following table shows the cngby)v. -/eidiploid chromosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused bythv6(ct45b34 /rczbn.wjkc q1ab a -r 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 wxo*bhv3 7;tsare th7o3vhsbtw;* x e possible genotypes of the biological father?

  Which row shows the correct annotation of thpb)*w 2fri mw:/bigg 4e alleles for blood groups?

  Which of these statements are true for,2+ki i io,wy6uyg-lwg1vw7sz.h oc9 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 inch93kedk9 bc5aidence of sickle cell anaemia and the spread of malaria across the continent 9 9kcb3h5da ekof 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 determined by a number xlw 7uu gm3:v8l,hohj ;(p+zpof genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) copoz,+pxl:(lj uw8u v m3ghh7; lour (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 ar,xrhart-6fl m )4am/nd unlinked genes.

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

Sickle cell anaemia is caused by the all3ho cih,1bt 4sele 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 ,j*1)ko7;vew w)wq 8e xu z5py*qqzr ycat that is homozygous for brown, long hair and a fe1w*)evyzywwqru; 8 o * pqzx),k5e7jqmale cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacumjl)wlhu3s -(tv: c 2jk officinale), the allele for diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) is dominant over short seeds (l). jwsht- k lvuj2c )3:(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), lo.csxy (v,a ys9ng 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 and female short, straight-haired guineaa(ssyvc.9 , xy 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 +vp 9k.kv w 6vq.rtb:0spvhb 5of the condition shown in the pedigree chart below? r hwvsv90kkp+ bv. tq6p bv:5.

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

  Which of these statements about genetic disorders is/t9l c;/dbi18toziys 1are 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 nokie m+/uqm o 7xtj( iyzhsw/j8 8)03ryrmal 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 disordvtys3,- n6,fzn kx vqkd:x0.ter shown in the pedigree chart is X-linked recessive and not autosomal xq,n3v -yxfn 0t ds.v,6t:kkzrecessive?

  Different species of living organisms have different nuji 89ru(y, 3q9 +lnkexdslrxvlbb/6 + mbers of genes characteristic to them. The table shows the estimated number of genes for fiveldy/xbu8 ixl 6q s9rn9+k+(v lrb, e3j 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 colour. mx7b*+;)n3ia mf +mz ikpe zz,If the pea plants Mendel was studying can only be white or purple and follow the rules of Mendelian genetics, which;mzf+z*e), mpiniz bx +7 ak3m of these statements was correct?

  A biological male with hemophilia and a biological female without 1 lczr6f galj7x.ql;u dguz)c: -pz48hemophilia have a daughter without hemophilia. What are the possible genotypes of the daughter? ;ul:f -7jz)p qc g6gdl8xal1zcr4zu.

  A dihybrid cross was carried out between two sunflower plants (Helx q7 vl6myrv1,16jpbegr 6 2gp;n m9leianthus annuus) to see if the genes for seed number and seed shape are linked. The critical value for thmllr96;1eq6e,j71vg x2 v nr g 6bypmpe 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 tyknc9lqnx+q 5:ahnzh+ w0t 94 -cknok;pe A and blood type B can have a child with blood type O.qka w5qc hck tkx0nn9+4on9z- :l;n+h

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

3.Explain the role of inheritance in genetic diseases.