A man and a woman have a daughter and a +ckpz-db7jq / son. Their daughter has normal vision, but their son is colourblind. Which one of these genotype-bdp k/cqj+ z7s could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic cell in ze)t6q dg-9-z+g8yel/qoxw ma human male?

  There are two alleles for flower1iemgrn /0fjj;v g) b( colour in snapdragons. However, the result of a cross between two heterozygous plants yielded offsprij)gifvejn1;mr (/b g0 ng 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 correcti2. irmd2 ywc/ 3xvw/j definition?

  Which of these statements is a correct defini oyaq55(g qym1tion for a gene?

  The diagram shows a pair of homologou e9/ (rrj)lp1i/he; w gwkp.mfs chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a speci 68m)vxd otte po2nkpe;30dn4t*w g +tfic trait, were crossed in an experiment. W6t2 g eon n)vt;otpd4m8xe*+3 pdt0kwhich row shows the expected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the ago*mq 8 dl qp70v6sk,7hekct 2rwuti allele causes individual hairs to have a banded pattern. The non-agouti allele causes hairs to be a single colour. Indic kshdrq6l7k7 v*,mp q wt08e2viduals 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 thirs3j3xp+jcu m i-(s-e seed shape in individual pea plants was either round or wrinkled. The results of an experimental cro3i(u3+jjr- -mpssx i css 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 chr4)o(3ceun 5su8ifg we8gth, nvhu2 +8;lxglhomosomes. How many chromosomes are in a )cwn;,eu 2 hv8s x8 u8 3e5gnugh+t4o (fhglilfertilised oocyte of a fruit fly?

  When does the random orientation of homologous chromosome pairs occubd8uo;3) tyj cr?

The majority of the genes in the human genome have already been mapped, me9f 1udn tnkfrjvgp 5yo1+g4 dgl165n1aning the exact locations of the genes on chromosomes are known. The diagram below shows one re4p5r l6gfn jd+ ngo 591 uyf11ndtgk1vpresentation 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 link;p(s ho7/t qyled genes?

  The diagram shows a karyogram of a brown male rat (Rattus norvegicus). Wfh94m hyir,8v5tw)s thich arrow is pointing to a pair of autosomest,5rhit w894ms hvyf) ?

  Mendel observed that there are two possible variatcnj4,np.azd8in1px4(4iy3 ia0ki ke ions of flower colour in pea plants, purple and white. After a genetic c3pyi8 4akdan4x ,ipz1n iiek4. j0cn(ross, 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 Londond oy)vc/s 50 d5*a+mtuwzdhn. in 1991. 0tnw 5dsdh acoz5d)m v. y/+u*

  Which of these traits is an example o /w*jd oox:(rnrr7gsps; ;j3r f continuous variation?

  Which row correctly descr8 w b3jur 3ctgv +3wfx5zfu8j9ibes diploid and haploid cells in humans?

  The following table shows the diploid chromosome number of a range of spe2+zni8dc h /mccies.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive allelremdwdx x ;p5(d cj ((j:hm+;ie (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 are uqzp q3v( r.9 ej(j.ulthe possible genotlrq.eu .q9((3jj puvz ypes of the biological father?

  Which row shows the correct annotati/w/c o. atozv 3l.f1zvo.o 7ffon of the alleles for blood groups?

  Which of these statements are trumvy qmeydg2yo .x+kc4+*g1(ue 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 sprik pjy,, j3lv4ead of malaria across the continent of Afi,3ljk vjp,4 yrica.


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 mmgxr,h2bf3u,0. nm9 mt blw. determined by a number of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone, bt.hmfm0 ,mgr2x.u3b 9n mwl) 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 gene8bg/3/bgx94x y 4cge( qb rexms.

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

Sickle cell anaemia is caused by -u em/koo3g:ypn h,i, 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 cro69zq4,b1wwhw fi3 e/uj(mqq vss between a male cat that is homozygous for brown, long hair, wf1/qw3(96q zj vwhm iqe4ub and a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), tklkmf4(4-e q*x nhc5phe allele for diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) is dominant over short l pe q5c4fn xk(mh-*4kseeds (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), 7z5+xn oqd)yhq4fuf 9long 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 guinea pigs and a chi-squared test (χ2)f9u f xqho+)45qn z7yd 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 o58ylh xj4t*udx gkuw j5 l/1,of the condition shown in the pedigree chart below? yju /udwxg1x5johtlkl 85*,4

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

  Which of these statements about genetic disorders is/are cor2tiot p6*hx8 plb;x a fo+ms2no6o7 g8rect?

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 sy/)6kk oajn u5how 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 lvm74 mawp ev;5.ewt d1acqp-.gb)) xin the pedigree chart is X-linked recessive and not autosomal recessiv1ea 7)w4 5-pcx;tq.edmwam .vbv)g lpe?

  Different species of living organisms have different numbers of genes cha0zatva de y;r7b3n92ijot 9/jt/u r-z olo7u.racteristic to the/aozbtz j90 rdn9 y 73jl v. /aior-to2e;u7tum. 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 flower cotlavu- :k 6clbbrn2zyq+2 -f2 lour. If the pea plants Mendel was studying cabc+ty r2-ua v2 2kf:l6n- lzbqn only be white or purple and follow the rules of Mendelian genetics, which of these statements was correct?

  A biological male with hemophilia ay7o3; azc-y yjnd a biological female without hemophilia have a a ycoy;yjz-37 daughter without hemophilia. What are the possible genotypes of the daughter?

  A dihybrid cross was carried out between two sunflowefkyina:81we gxrgc l1 cq5:u 4:12jsbr plants (Helianthus annuus) to see if the genes for seed number and seed shape are linked. The critical : 1yrcke:41 wn:i g 8q 2lafxb1gc5jsuvalue 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 can hy/j3 nuuk30dn.xc7e3nfyo m 4ave a child with blood ky7 o u3cnfu.exn3nd4j0m3y /type O.

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

3.Explain the role of inheritance in genetic diseases.