A man and a woman have a daughter and a son. Their daughter has normal viu ;vaf qik c27)wb :nqb90n oxph6/a*wsion, but their son is colourblind. Which one of these genotypes could be correct for the biological motherwq b7b9fp v62)n/xi*qunckwo h0: a;a ?

  Which diagram shows the sex chromosomex-xe h-nor2y2s of a somatic cell in a human male?

  There are two alleles fr04w fdodf;.uxet g qwc v7:-,or flower colour in snapdragons. However, the result of a cross between two heterozygous plants yielded .woxeu -7rt0,; dcffw4 :dqvg 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 correct definit9juriy 88p ru;ion?

  Which of these statements is a correct defq -k k : 8bbex mryb1ien*kk(tl4i5y4:inition for a gene?

  The diagram shows a y6mr2 a ;i8zyr1 ,a1pzyrb8ydpair of homologous chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a sp 7rxdqj7klkhd,wgsj8*)6s 3s ecific trait, were crossed in an experiment. Which row shows the expected phenotypiqjh d,xsdswlj8g3r 7 76*k)sk c ratios of the offspring resulting from this cross?

  In some animals, the agou1eht s5zeka:-ti 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 ha:-k h51tezsa eirs 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 indiv0ciiwqvh-z2 8 za.uw,r1 uglk1l. b0uidual pea plants was either round or wr gqlik8vubau .,2 1whz u0 0l-wrci1.zinkled. The results 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 melanogasu. p8.j+ cxc)io+prtb a2f9s yter) have 8 chromosomes. How many chromosomes are in a fertosiyr9+. 2 pu)8a+fb .tccpxjilised oocyte of a fruit fly?

  When does the randomtw-r 25q2r2knvnc 3 wub(navri4gr63 orientation of homologous chromosome pairs occur?

The majority of the genes in the human gen+sz. vuvpoi/ron; c0.ome have already been mapped, meaning the exact location/ c0ouizv v.r ;o+s.pns 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 definition of linked ge1r +r8)v n y/( zx3y.kzxxzddznes?

  The diagram shows a ka6mb::,-rhwi j egt78qqor ;fpryogram of a brown male rat (Rattus norvegicus). Which arrow is pointing to a pair of :p :rjw68-tm , ;fqgqeh ib7roautosomes?

  Mendel observed that there are two possible var;cw)p nrh9ky5 gk/kr1 iations of flower colour in pea plantscpwnk/r)kh1g 9 r ;k5y, 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 bornhrx:d:x 69 v3,c 6nwbkdfxm4n in London in 1991fk 6:9d36 4m wv h,x:dcbnxrnx.

  Which of these traits is an example o- j:p sg0tpyx ,yrzj:vny/f3 )f continuous variation?

  Which row correctly de ohd t0:/)qhgovf/: ktscribes diploid and haploid cells in humans?

  The following table shows the dipl:5ibig: cxgy/ oid chromosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by az w6jj*:76 ;y p+7enj 5c jggdit+qlul 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 p1hp(aaz ae 9 57-ycogA had a child with blood type O. What are the possible genotypes oayh 9-1g(eazoc7ppa 5f the biological father?

  Which row shows the correct annotation of the alleles for blood g:va9r7 gpj1d hroups?

  Which of these statementu3tjg8kub4kpc 6(8 gio7leq;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 anaemia and the x gppe/,b:8m iqj o9kfe:v z;ox;k8 8kspread of malaria across the continent of Africbxq zopx8/;mko8f g 8;ij ::ke,v kpe9a.


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 nnj, ssk.lcc8 4umber of genes. Brown colour (B) is dominant ls. 8n4c k,sjcto 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 between linked and unlinked n.xpx/s ;t smn)j/n 8.ikupe97az ;oigenes.

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

Sickle cell anaemia is caused 6rv*i xnb (y.c+2lr1wfhrz(q 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 homozygous for *d/xsx td2mcd o 5,0bzr. e*xudq20ad brown, long hair and a femaleor0 x.abc qe0 *s/md d*5d2,xzxut2dd cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxaciu0u. 5; bpa9qvd rjww8p:t7sr4qbb9um officinale), the allele for diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long s94 b.r0swtj7vwqpu: ipaqrd5;u bb89eeds (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 (Lk/4/02 nwrb bb ztzgs5) 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 te5bz4 2 /srgz/bntbkw0st (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 conditiozuk(m., p-c i d9:hwrtwv75l,s 8vxign shown in the pedigree chart below? (wr-,9.:lm 7w p s5 xtc,vvizh k8idug

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

  Which of these statements about genetic disorders is/are )s() .szcv 6qxucl ygl2t6v n: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 tr;) )0w fwncigos/q +cqaits 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 lt vcj/8 ,+wgbn4aw a3,ixl1x pedigree chart is X-linked recessive and not autosomal recesst1 cx,gw43a8/a w+iv l l,bjnxive?

  Different species of living organisms have diffexkj+9url(gcug88b k4h* g7 kxrent numbers of genes characteristic to them. The table shows the4x* uj79 lguk( rk gxhk+cg88b 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 ofw2ujfgwq5f4-pt* ,gr pea plants, including flower colour. If thguwpj f-,t42*5g qfw re pea plants Mendel was studying can only be white or purple and follow the rules of Mendelian genetics, which of these statements was correct?

  A biological male with hemophilia and a bioxvtyzya:. :u; u3oc8c9)ap mzj0vz v(logical female without hemophilia have a daughte(8x:c op y0uy);zvvumj 9v3zz a.ta: cr without hemophilia. What are the possible genotypes of the daughter?

  A dihybrid cross was carried out between two sunflower plants (Helianthus a0y ;cqp4:o// +bdrz y81kdti pkpjk2znnuus) to see if the genes for seekpzpq /zyrbc:+pi k1;o208 tdydj/ 4kd number and seed shape are linked. The critical 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 blood typ,v5s 6kl;lml ae A and blood type B can have a child with blood type ;akms,v l65l lO.

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

3.Explain the role of inheritance in genetic diseases.