A man and a woman have a daughter and a son. Their daughter has normal vis b;okx-p gjkws6644bmion, but their son is colourblind. Which one of tb6 sj;km4bkx 4wg-op6 hese genotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic cell in d5mmah;z0zf .a human male?

  There are two alleles foru6.haew9csj ; flower colour in snapdragons. However, the result of a cross between two heterozygous plants yielded offspring with three different ob.je;haw 6 uc9sserved phenotypes, red, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to the correct definitioggpryr 7ng91 0uw/zez4 5)t vtn?

  Which of these statements is a correct definition for a gem2ev is,3nh 2vne?

  The diagram shows a pai sit8. je;0njvr of homologous chromosomes.

How many loci are shown?

  Two individuals, heterozygous fo wsqlip39,5t lr a specific trait, were crossed in an experimenti39l,s5pwlq t. Which row shows the expected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti allele causes individuah+qt39 fs kt-59 eebxkl hairs to have a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who are heeb-+ h xf5k9te3ktqs9 terozygous 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 plants wasgx-2 nqrkhm0- either round or wrinkled. The results of an experimental cross yielded 315 offspring with round seeds and 105 offsprix k0mg--nr2q hng with wrinkled seeds.

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

  Neurons of the fruit fly (Dro6 d;fz/wie mxnm8l*10o mwa a6*c va*ksophila melanogaster) have 8 chromosomes. How many chromosomes are in a fertilised oocyte of a x*8n*w1 *amd6efkmwcl iav / azm06;o fruit fly?

  When does the random oriengync1 o5hbl,ic. lr 9; :jrrb0tation of homologous chromosome pairs occur?

The majority of the genes in the human genome have already been mapped, m +i9.*ot epxmueaning the exact locations of the genes on chromosomes arei+em.*pou 9x t 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 def.ep( c4htea j*inition of linked genes?

  The diagram shows a karyogram of a brown male rat (f6 o0ft smbf(az. qmh.*hs+k-4mim;vRattus norvegicus). Which arrow is pointing to a pair of autosome (k0. shma t+ffvzqs6f m ib4.*;mh-mos?

  Mendel observed that there are two possib16g z hyx9p+xxle variations of flower colour in pea plants, purple and white.x xpz g9y1xh6+ 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 L8f9p.tcdf+a condon in 1991ftp+9ac. dfc8 .

  Which of these traits is an examp1: coxlw2ylp(s68* ohkjh sx6le of continuous variation?

  Which row correctly describes diploid and haploid cells in hum4i l.jmcb-g7f+8 ds)ke w- mesans?

  The following table shows the diploid chromosome number of ucaljw2zuz58 5n gyg0 (s3t8aa range of species.

Which of these statements is correct?

  Sickle cell anaemia is f *m);skkpxa2w fcs)9caused 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 had a child with blood type O. What-v4sr p1 3aovw are the possible genotypes of tw3va rp-4osv1he biological father?

  Which row shows the correc f4tjtksp1(it -wpr7 :t annotation of the alleles for blood groups?

  Which of these statements24(9si2-cblpn8+eygfh hocpw- ax agr 0 q0m- 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 ma3e2rb e u7d+neom 6.l3qf2pvjlaria across the continefej+d ml3.3peo7bu vq e 6rn22nt 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 dpu1c1y 69ijbzp r deq8e/y. )setermined by a number of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) colour (P) j b )p1d eep8cy1uy6z q./sr9iis 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 alzp5v*wegdb.4 ) j lu1nd unlinked genes.

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

Sickle cell anaemia is caused by t 7i9a*6ukdjmnhe 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 t*hp.8(fwinc lhat is homozygous for brown, long hair anhln*.(w8p fic d a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), u rl0ox+q)v )hthe allele for diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) is dominant lohq) r) u0+vxover 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 dn,hx86yznv p5ominant 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 tex 68pv 5,nhnyzst (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 shown in the pedigree chartdow07 gria5 d( belrwa(di05 od 7gow?

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

  Which of these statements about gene 1k mz,a jmat(cn4r6h6plc ;i1tic disorders 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 8jx tz9ff fn7t1 ue1jds 9x4;ktraits can show 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 cu -a 7a 0sp3mjsurb1qi7s2/ fbhart is X-linked recessive and not autosomal rec3uap0f/7 ui-mr2bs b1a7jqs s essive?

  Different species of living organisms have different numbers y1qf u z ep,8ar9,v,lmf 4eym;of genes characterist 1me ,fe 8,u9,rfyla 4;pzymvqic to 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 *spbqpz f1on*y0r l0yz g 6h90of pea plants, including flower colour. If the pea plants Mendel was studying can only be white or purple and follopls6z0q 109p*oygbnzhf y0r *w the rules of Mendelian genetics, which of these statements was correct?

  A biological male with hemophilia and a bio 4u li.w8s6xkelogical female without hemophilia have a daughter without hemophilia. What are the possible genotypes of the daughterxuk. 4s w8i6el?

  A dihybrid cross wasvm8-k 69)yiua tar.hw carried out between two sunflower plants (Helianthus annuus) to see if the genes for seed number and seed shape are linked. The critical value for the chi8uy6-i)a.ahtr9m wv k -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 have a chiuo3n c+5f 0v :mo5 ;wgdpbsvi.ld with blood gb5m+u; n c05o dfvwv3opsi: .type O.

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

3.Explain the role of inheritance in genetic diseases.