A man and a woman have a daughter and a son. Thef6w(l:vz 4yd bir daughter has normal vision, but their son is colourblind. Whzd4by vf l6w(:ich one of these genotypes could be correct for the biological mother?

  Which diagram shows the sex ch4.f8)jubk ) 6ux7ge,mp soamwromosomes of a somatic cell in a human male?

  There are two alleles for floweryt wu( m.3lyi3 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 i(iy3tw. ly m3us the most likely explanation for this observation?

  Which keyword is matched to the ynz)y(s/ xr*ecorrect definition?

  Which of these statements is aquw 534kuyy;a correct definition for a gene?

  The diagram shows a pair of homologous chromosomxul ./h 2w(o9ictl 04/+iiwfcoa*bd des.

How many loci are shown?

  Two individuals, heterozygous for ay3a4c fjd ,m(9-s lix8ygur:q specific trait, were crossed in an experiment. Which row shows the expected phenotypic ratios of the offspring resultingamxur :j-9l,4ygs8 q 3i (yfdc from this cross?

  In some animals, the agou)vebo nl96ubw;( 3 bbgti allele causes individual hairs to have a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who are heterozygous have hairs with a g)(wvu;be9 bbl6o3 bnbanded 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 plants was either ry.cnbn 6ew2fcf s2c90 ound or wrinkled. The results of an experimental cross yielded 315 offspring with round seeds and 105 offspring with wrinkled 2n2nyew c.bf fs0c9 c6seeds.

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

  Neurons of the fruit fly (Droso71-rtm(y /( vno kcbvl3lr u(wphila melanogaster) have 8 chromosomes. How many chromosomes are in a fertilised oocyv(y(vwb -m/3lctnou( 1r7rlk te of a fruit fly?

  When does the random orip* oh9ew)t2 thvz8na0entation of homologous chromosome pairs occur?

The majority of the genes i;bnrc)s jlr2 ykd* 9:nn the human genome have already been mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one representation of a homologous pair or;bl9ks rn)n jc*2dy:f 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;h 1rpzjd85 ke linked genes?

  The diagram shows a karyogram of a brown male rat (Rattus norvegicus122qffma s lz,). Which arrow is pointing to a pair of1s f a2q2zmf,l autosomes?

  Mendel observed that there are two possible variations of flower colour in pea e.ps sc2l 9i.hd9q(s0xdw p k;plants, sdew02hlpxk9ss(;d pc.i q .9 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 parents?

  The graph shows the frequency of birth weic /9kbdzz,1oq)qo 4 0x9y.u zzeqsst/ght of children born in London in 1991o4sx/c/qz1zoue ztd0sqkz9 q,y9 )b..

  Which of these traits is an example of co7 -3zj6mteh9vauy0f6lyqbgc+ su 4cyp ;.v5a ntinuous variation?

  Which row correctly describes diploid and haploid cells in humansuro 5gikmv 00:?

  The following table shows the diploid chrysbdr7cj ,.7c omosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive allele sykv354g+zllk;(topx6f4 ig +-xwb v (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 typ8n2xcstdso8 3d 1ul r,q+b rh-e A had a child with blood type O. What are the possible gu1odrt, - 8xsdrcb 2h38lqn+senotypes of the biological father?

  Which row shows the correct annotation of the +zq u6/id(v7e fmirsn0;0 baualleles for blood groups?

  Which of these statements are true for(k0mj o:w5cw/q4rvea1e ibe9 :wdk (c 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 anarfwnvg8)wa dp 56 sz 26:rbn(wemia and the spread of malaria across the co6g5 f wza:vn6pswdw(nr 82br)ntinent 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 k t hnrj:;c +cjac7lhbn29)04u0 w gpia number of genes. Brownw pnlirch :0jhuj9;2g )4+kbtcan7c 0 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 betweed 98jbbc+ ahc8n linked and unlinked genes.

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

Sickle cell anaemia is caused d(p*ybxw0mc)m(f9 t jl23gdxby 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 homozygous fou d 6qb/dxc*xpqig; 86r brown, long haird6gubxqi8x * /d6cp; q and a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamond-shlb/6obqh 99lfaped seeds (D) is dominant over oval-shaped seeds (d) and the allele fofq6 b/l99 blhor 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 shortwdc bx. 8,ue51ulei 1cb yg).t hair (l), and curly hair (C) is dominant to straight hair (c). A test cross y1 8).wu dxi5 ue,l.1cgbebct 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 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 conw igyj+6vp+;0 dpr a-rdition shown in the pedigree chart belowjrrdvw+a+pi 0g- 6 yp;?

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

  Which of these statements about genetic disorders i b75hd15 wwcfeqq13nhs/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 qo*68qv- oueidistribution.

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 dcx2/r0 4fmo;/yy r-cm3uf:y9g qza qv isorder shown in the pedigree chart is X-linked recessive and not autoso-mqz 3r g4vrf2ac0/ o :m9/;y quxycyfmal recessive?

  Different species of tx ifbl82;g7ntrk1 /-q 6lfmm living organisms have different numbers of genes characteristic to nqxkm f 1mf-6lti8b lgt;2r7/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 floweo/s zjf (7fe+yr colour. If the pea plants Mendel was studying can only be whfj(oe sy zf7/+ite or purple and follow the rules of Mendelian genetics, which of these statements was correct?

  A biological male with hemophilia and a biological femalgnfcj likcn;) d1 3pj.bw,*n4e without hemophilia have a daughter withou13j c)*;,jnfnpkn cd.4ilwbgt hemophilia. What are the possible genotypes of the daughter?

  A dihybrid cross was carried out between two sunflower plants (Helianthus r5-o:-f ggvgwannuus) to see if the genes for seed number and seed shape are linked. The critical value for gw v-5fgr g:-othe 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 halkz5yne-j/ , ,g guojd-8v,i o*n lmv:ve a child with blo ezm,-ng,*o -onvljk dv8u,lg5i: / yjod type O.

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

3.Explain the role of inheritance in genetic diseases.