A man and a woman have a daughter and a son. Their daughter has normal w)gjf xebvmf ,26 p/lb+e-q 0 dh9tbr2vision, but their son is colourblind. Which one of these genotypes could el609hf)/vg 2bbqpmxwj d trbe2f,+-be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic cell in ;;, flrft2l paa human male?

  There are two alleles for flower colour in snapdragons. ;+km / ;kk5vtfgjzjae)1t/bxHowever, the result of a cross betwg; akfmv+ ttj/5/k 1)kxe zjb;een 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 correc jd8z16/wvuii t definition?

  Which of these statements is aq ;2 gg+roq(lp+ w4ln9zfep4d correct definition for a gene?

  The diagram shows a pair of homologous chromosome5bet5a zh95i) dzop;ns.

How many loci are shown?

  Two individuals, heterozygous for a specific4in7 trcq8grc p;i1 2c trait, were crossed in an experiment. Wh41cn;7qci 2 8rricg tpich row shows the expected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti allele causqjh/ -8 oaah2dz9z; rves individual hairs to have a banded pattern. The non-agouti allele causes hairs to be a single colour. zvq z;haa89d2o-r h/ jIndividuals 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 pcoe b9g-:8b0iiq/b zqfxy9jv d4, ;a bea plants was either round or wrinkled. The resulxdcf4oqibiq;z:9/ bvy b-9, g0eb8 ajts 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 (Drosophila melanogaster) have 8 chromosomes. Ho;) cex/)(u6j a u,oqpptq yig5w many chromosomes are;j pteq( a6g)u/cxopu5)iq,y in a fertilised oocyte of a fruit fly?

  When does the random orientation of homologous chromosp7cg1pgp l)0ql/ dmh 2ome pairs occur?

The majority of the genesvkbr6 + w )e3 dbe-/rlnyln/c(eu*e4 t in the human genome have already been mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one representation ce(een nbrr6+ wkltd3/*l eb/ 4y)-uvof 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 linked genes?hmqs)*f88 ttsg wlt mm7n3m.(

  The diagram shows a karyogra w1:xij0cf*3/njz a oom of a brown male rat (Rattus norvegicus). Which arrow is pointing to a pair of autoo*xf1: j3jza0 oiw/c nsomes?

  Mendel observed that there are twof zt*zv0mmb2e 1)* ioo possible variations of flower colour in pea plants, purp2*vb *imez0 o)fo mzt1le 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 f:1do w;w ftow,requency of birth weight of children born in London in 1991. oftw ww1;d :,o

  Which of these traits is an example of continuous variatioivw/)-bfo()m kj; qn* 7 cucrrn?

  Which row correctly describes diploid and hdz2b4e0 l2umde,sc; 5ph g5vr :zot0maploid cells in humans?

  The following table shows the diploid chromosome pg 7nv :h)wgd5number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a 1das7ahd86sr 5jc 6f;rsig8z 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 p4ij/:e.)eqk0dt yz btype A had a child with blood type O. What are the possible genotypes of tik 4p0/t)je qyb d:.zehe biological father?

  Which row shows the correct annotation os+nedwgf0. m *f the alleles for blood groups?

  Which of these statement9i safcz:1w e(s 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 anaemij d booo*d:+9aa and the spread of malaria across the con9o do+db*j o:atinent 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 nxblwurw4 m*;(umber of genes. Brown colour (B) is dominant to sandy colour (b) and awr(4uw*;b x lmn 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 linked and unlinked gen6cdr3fcqk-dxq2z +;k es.

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

Sickle cell anaemia is caused by the allele 87sx./hn quwc uf np,9Hb$^S$ . 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 for brp:pju(5- gw qcl:izy (+(j 6az(qsxkiown, long hair and a female a((:xq :pzkcgj z5i-y(+ilwujsp 6q( cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamqq42khu galo42v6;pnd o8r-6mmgd r +ond-shaped seeds (D) is dominant over oval-shaped seeds (d) and6rmm2a +okg4;q862 d opq gd -l4vrhnu 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) isg z7y+* :rxph/f :9ozfuf5 ttf 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, cuhorx/gfytz ftf+f59:*zp7 :urly-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 vp7;me(ad6qg/hqew9:;vu8 h y) rmf r5zpg v6the condition shown in the pedigree chart vrgm pd5q;:7g/6h9uhpy rfv)8qe;ev 6zw (mabelow?

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

  Which of these statements about genetic disorders /sq.9jhe.pxysu t yr;+p:d j)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 normal dis:fr no-4cv r;zrz9md3 tribution.

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 the17 g478c dz cvllu0ol65cagli disorder shown in the pedigree chart is X-linked recessive and not autosomal rec7cl gaiou5d c4cgv7l 1 0zll86essive?

  Different species of living organisms have different numbers of,kw+mc cp:ztio v7ny0k4(4i h genes characteristic to them. The tab:t07 ,+myp(hvonci 4wk k4cizle 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 c:) nrcv6yryy2x 7, rtgolour. If the pea plants Mendel was studying can only be white or purple and follow the rules of Mendelian gey6 gy:vrrxn),2 r yt7cnetics, which of these statements was correct?

  A biological male with hemophilia and a biological female without hemophilia ha.8g aftd-k iau)kqt)yuj3)9b ve a daughter without hemophilia. What are the possible genotypes of thebd -)quf3jau98).aktk ti) gy daughter?

  A dihybrid cross was carried out between two (/fo k:gj4xwasunflower plants (Helianthus annuus) 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 calculated4o /afw:( gjkx value for the chi-squared test was 10.05; what does this indicate?

1.Explain how parent1tvzp (/mal ri/cvsc/ 8g xs6;s with blood type A and blood type B can have a child with blo x /(mzlsgca v8cts/i1/;6rp vod type O.

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

3.Explain the role of inheritance in genetic diseases.