A man and a woman have a daughter and a son. Their daughter has 7eoou7zba 1 yg0+)xg sg(orm)normal vision, but their son is coloux7o1sogazg 0b(e)uryom+)7g rblind. Which one of these genotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic cell in a humcs uubxuz6a20n.*q 0 kan male?

  There are two alleles for flower colour in snapdragons. However, the resoig/lox95 .ld ult of a crxl5id/.og9lo oss between 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 mat52asci : 2r1-q7)xwa x.ff zc,zutb(e yhu-zjched to the correct definition?

  Which of these statemen-v4)xucre u( cts is a correct definition for a gene?

  The diagram shows a pair of homologous e5p: x4 d8tmfgchromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were cr1dwn.d/*2xy(czw +)rpj7y*m jjbso l ossed in an experiment. Which row shows theco ry) py*ls*d7d x+wjbn1j 2(wj/ zm. expected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti allele causes individual hairs to have ;ri;pssiw ka8);8 *tcovy kj. a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who are hv jii; 8rs;ksacwoy ;)pk.8*teterozygous 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 peaw0 ryiy1g mm/* plants was either round or wrinkled. The results of an experimental cross yielded 315 offspring with round */y1rw gymmi0seeds and 105 offspring with wrinkled seeds.

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

  Neurons of the fruit fl vo7ofuh/z3u : y3-gqcy (Drosophila melanogaster) have 8 chromosomes. How many chromosom:/7oocufq3v- yhgz3u es are in a fertilised oocyte of a fruit fly?

  When does the random-1qkv2 l ( bbsqaf05tt orientation of homologous chromosome pairs occur?

The majority of the genes in the huma39ls6 e1apm++lgt)1n isw3u pvzn0x b n genome have already been mapped, meaning the glan)0v 3+s+ bipxu9n 6tsezwl13pm1 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 definitionvy).7 yx mkwj3 of linked genes?

  The diagram shows a karyogram of a brown male p) y fu7hx:sy,y22fphno8l+ brat (Rattus norvegicus). Which arrow is pointing to a pair of autosom,2yph:)2uf+l7y o h pnsxb y8fes?

  Mendel observed that there are two possible variations /1d *lhyc*pyac sq35 bof flower colour in pea pla dyslca5 3y*/ 1cb*qhpnts, 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 weight of children born in Londo4f+ mt :djswu:vq b*8tn in 1991.* +4dsmwqtt:vbu :f j8

  Which of these traits is an example of continuous variatjklw6a +js: b1ion?

  Which row correctly descrioe*z y*0p i-nj;z; mjq pczl;2bes diploid and haploid cells in humans?

  The following table shows the diploid chromosomcs kd o3tk*.wnm50;cxe number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is p+l-sm0kw qs. caused 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 vhy4lcgc;.w7 i8 t xq3with blood type A had a child with blood type O. What are the possible genotypes of the biological 38 htqv;wilcxg 4y7.c father?

  Which row shows the correct annotation of the +1dkesy33 lw( +sa plqalleles for blood groups?

  Which of these statememr/fu7*ts+ 6fdh 4iqw nts are 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 sickle cell anaemia and the spread of malaria aiwp4wkzq1,hf cx(66c e4ny 4ocross the contix 4y(k qp,ofnc 4z6w1whe6ic4 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 determinown9jjk)p3:44m 6cc9jkf xza: c i5jced by a number of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) colour (P) is dominant to one tonj 4mk jknjwx4 joc:6icza)fc9 c95: p3e (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 uty4u em-a;zsco ;0,band unlinked genes.

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

Sickle cell anaemia is caxbzuxoybe,:x q e8,/+ used 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 homozygo)lpj*,j6pwvg cm; 3zcm*g b/t7 jk4 uius for brown, long hair and a female cat that has black, short hair.ic vctlb g )mjuk34* gjpp 7zj;,wm6*/


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamond-shaped seeds (D) i ;fslezy775 ftrd9y3t s dominant over oval-shaped seeds (d) and the ay5d 9f;lfser 77ztty3llele 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 x u)ik:*vo9f phair (L) is dominant to short hair (l), and curly hair (C) is dominant to straigh :iop9*xf)uk vt 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 (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 condition g0g;-kpeyd*c6p( m yl shown in the pedigree chart l;-60d ym*ygpgkepc(below?

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

  Which of these statements about genetic kvvjo2n;mbu4kig8mi5-t ad ;7 c57 zvdisorders 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 norm8e et,ecr(10 a 3yvssral 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 showx(s b.tn if8m6n in the pedigree chart is X-linked recessive and not autosomal re (8ism.t6nbxfcessive?

  Different species of living organisms have different numberf vt.h*/j c-jes of genes characteristic to them. The table shows the estimated number o-h*jfejtc/ v. f 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 characteribmdne./*kdsqlya - d+4v59h wstics 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 s9q l5n-dyk md +wh./dvs4bea*tatements was correct?

  A biological male with hemophil(oo pl *y:m9hzkc- /zaeh-3ebia and a biological female without hemophilia have a daughter without hemophilia. What are the possible genotypes of the dauyh *cmb 9ep(l-zae3ko:-oz/hghter?

  A dihybrid cross was carried out betwea 0ywbw*m5nk6 (f e6iyen two sunflower plants (Helianthus annuus) to see if the genes for seed number and seed shape are linked. The cywm6bn6aw* k0e 5i(fy ritical 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 kpm v x*qkg)343ijf msq e92x(blood type A and blood type B can have a child with bloodg23m4e3 j* ikf)qks qmvx(p9x type O.

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

3.Explain the role of inheritance in genetic diseases.