A man and a woman have a daughter and a son. Theipk*u1nuxe qhj8 m0shfm 800(,q+s r dmr daughter has normal vision, but their son is colourblind. Which one of these genotypes could be f( jrke8m0* ms u, mpuq08dnxq+hh01 scorrect for the biological mother?

  Which diagram shows the sj.71w8oud wz:kg q6*y 9k uwtoex chromosomes of a somatic cell in a human male?

  There are two alleles for flower colour in snapdradx0 2qy5bxr)vhuws-; 9q fgr7 gons. However, the result of a cross between twwh y; g2 qxxd)50qb-r7uf sr9vo 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 correct ds:xzyaayl i z+ mj bd2.h4y4,7efinition?

  Which of these statements is atumytb 2c+)o2w x,c4z correct definition for a gene?

  The diagram shows a pair of homologous co tk;heny9w r2a5;5 wshromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were crossed in an ex86aawocnc 95, 6ol0qur)o mex periment. Which row shoco,cm q ao)09o66u8ln rwax e5ws the expected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti allele causes individ3gmi;*f;:mtx nx8um kual hairs to have a banded pattern. The non-agouti allele causes hairs to be a single coloutn 3i fm ux;xkm8*m;:gr. 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 plan 4:wudsg;d. g77nmfkcts was either round or wrinkle;sc7.d ku:fgnm74dwg d. 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 u y2udj1 *deldeq7* n((Drosophila melanogaster) have 8 chromosomes. How many chromosomes ar7*dln(*2ey e1quu djde in a fertilised oocyte of a fruit fly?

  When does the random orientation of homologous chromosome pairs occurl7 beqaw;8a uf7-l()ydw0 t3 r,klsy w?

The majority of the genes in the human gel5 vzwgk2 zu.d+wgv96nome have already been mapped, meaning thw+29u l6gg.zwkdzvv5 e exact locations of the 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 lig (z5 yjz( 0ra)1t;s9sho:wv twz) duvnked genes?

  The diagram shows a karyogram of a brorke7g9wq )(h f ofj:.dwn male rat (Rattus norvegicus). Which arrow is pointing to a pair of autosomes?ewjgfr9q:fko. )7 d (h

  Mendel observed that there are two possible varnr 9 b-uqnfy b zuvj1xv,0::6eiations of flower colour in pea plants, purple and white. After a genetic cross, the ratio of plants with purplv9n1b eun yv,fr6xu:0 -z jqb:e flowers to white flowers is 1:1. What were the genotypes of the parents?

  The graph shows the frequency of birth weight of chiunc zg x3/bk s)o5c*c8ldren born in London in 1991c*zoc38k un)x/gbc 5 s.

  Which of these traits is an example h;u*qptgzl1 n-n6 xmpq -n .,fof continuous variation?

  Which row correctly describes diploid and haploid cells in -1fah:bgzo9 5oq7jps1x(xyoo gj*1 khumans?

  The following table shows the diploid chromosome numbwd8 p.:mth pj0b/)s,slg5vk aer of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is cauqfwiya8zn : 52sed 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 type A h09:ef oz f2jz, z-ubb*fjsfo2*a au 5pad a child with blood type O. What are the possible genotypes of the biolu ,fjab90opzze2u b-2* fjf *fs5oz:aogical father?

  Which row shows the correct annotation of the alleles for blood g 4fu:0o3vtj u cus(fj+roups?

  Which of these statements are true for alleles*6t2a g6 neh( m:sipywsg.w6g?
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 ww+o0 b;r/ dq,e )(z uacwbzq2across the contiucb z(wbo qw zq)w2;ar0 de/+,nent 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 is determined by a numbegv98uy g wlg usxw;(8crsm*/ 3r of genes.v r s*u/3 ; w9u8(gsw8xlcgygm Brown colour (B) is 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 between a390em3zan xalinked and unlinked genes.

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

Sickle cell anaemia is caused by the allel zabpel7r2rp1*8mlqb-+ g6dje 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 8sfupk de60,cd+zac* 4tbnvq z s0/4cfor brown, long hair and a fema*cck,+0s 6/z 4v 4epdusaf qbcnz 0d8tle cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamo0bwuk:1*l zj quv,ko-nd-shaped seeds (D) is dominant over oval-shaped luqu v0z: kjbow,k-1* 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 (lp.03 gbg 1h z35dxmz1tfb1rc l), and curly hair (C) is dominant to straight hair (c). A test cross was carried out between male heterozygous x 115chr30 l bbdzp mzg1.t3gflong, 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 t-s m:h 0( 0rrtx tq-3zhzovfaa2/5ksyhe inheritance of the condition shown in the pedigree chart beloz tm or0x:kz-(2 sht/rsa3 -0y5qafhv w?

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

  Which of these statements about genetic disorderqgmk rq bj-:r-yzf3x 7- oxs 7q)ghw;6s 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 showhy 87 f;*fx,2a xg,iofv ry3uo 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 inheritance of the disorder shown in the pedigree c 6b-cycoq/-trhart is X-linked recess obt-c-y/ c6rqive and not autosomal recessive?

  Different species of living organisms have different numbebe+e j4tlue5ffjy gv8h6k1( s/y0ii*rs of genes characteristic to them. Tuf+ ye81i y6(e 40lfkjveh /gsbtji5 *he 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 floweise.)mo8 xad*r2uk4qk, m uj:po1u6gr colour. If the pea plants Mendel was studying can only be white or purple and follow the rules ofkae p,8 ojs.ki: *u 2 41o6)mmrudgxuq Mendelian genetics, which of these statements was correct?

  A biological male with hemophilia and a biological female without7i8fs+i pkn bg..)3ufr u q1lm hemophilia have b lqu+mk . f.fgr)i1i7u3p s8na daughter without hemophilia. What are the possible genotypes of the daughter?

  A dihybrid cross was carried out between two ja n8c )ln+8umsunflower plants (Helianthus annuus) to see if the genes for seed number and seed shape are linked. The crn )8ln jau8+cmitical 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 5owt)3x r9pbfcan have a child with bpboxr fw35)t 9lood type O.

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

3.Explain the role of inheritance in genetic diseases.