A man and a woman have a daughter and a gq/ hrx zn.9hh5p s0w:son. Their daughter has normal vision, but their son is colourblind. Which one of these genotypewqg/sx9zh :nh r.0h 5ps could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic cel*q ;,d kp3vqp5ooos9 fl in a human male?

  There are two alleles fo5u1-5 )2o rt - ludmk2lcfatoer flower colour in snapdragons. However, the result of a crod2--r 1 eu otckt5lul)5m fo2ass 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 matched to the correct defajmd6; /87wk/uxowblzv jg2h9 ocd4u,r *dj;inition?

  Which of these statements is a 8kp0f,t hzn6 gcorrect definition for a gene?

  The diagram shows a pair6 wo1jkv3ty0 z/ru(y d0qeg7s of homologous chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were crossed in a ci l)cfh t-pse m)*sbifw(7;0uhk5t2n experiment. Which row shows the expected phenotypic rath fus2bwil t;)0spkc5hmec*(t) f7-iios of the offspring resulting from this cross?

  In some animals, the agouti aller6:(t yg7fyo +8eig;o 8vz qlwx 0nu3vle causes individual hairs to have a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who are heterozygous have hairsn6yugw :lxv8 ;o(zfg3r7y0tv8i q+ eo 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 pea9 o byju35ri )ex9xz+k plants was either round or wrinkled. The results of an experimental cross yielded 315 offspring with round seeds and 105 rjb x9yu5oe9z x)+ i3koffspring with wrinkled seeds.

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

  Neurons of the fruit fly (Drosophila melanogasthhr2zsfzzg l+34u l5)er) have 8 chromosomes. How many chromosomes are in a zlgf2 +4s zrhu53)h zlfertilised oocyte of a fruit fly?

  When does the random orientation of hom gs42tern op8q)k6y+ jologous chromosome pairs occur?

The majority of the genes in the human genome have already been mapped, m , h/iqxmma4b29yqlg8e5 crt1 eaning the exact locations of the genes on chromosomes are known. The diagram below shows one representation of a homologous ca2 8qm behqrg45/lmt ,9ixy1 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 dnh 0 e ujo8h yjjsxz*mv:;;02yefinition of linked genes?

  The diagram shows a karyogram of a brown male rat (Rattus v+zrvgst1b,9c7u0bl norvegicus). Which arrow is pointing to a pair o,bbztucg rlv +7s0 1v9f autosomes?

  Mendel observed that there are q45 hr02 pfeyvtwo possible variations of flower colour in pea plants, purple and white. After a genetic cross, the ratio vfph 20er4q5yof 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 puaqq u;1prq9k,aoe(m w.v 3 3of children born in London in 1991. qr. k;pp3ve qa9a, 3uwuq(m1o

  Which of these traits is afnqnu3.gt6 . yn example of continuous variation?

  Which row correctly descrc8mukwm1 00d+ yn-.e lgkii3t /,9twasldd7 z ibes diploid and haploid cells in humans?

  The following table shows the diploid chromoez 1ai/:f qpmoa5:8 ovu -fxt1some number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is cause8isy/ hvaa td+nfc,/- d 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 -hx*ac 6xwrpprswoln x2p+ ,-+a(*ox a child with blood type O. What are the possible genotypes of the biologip*l(rc+-hxo,p 26ax *war + w-sxpxon cal father?

  Which row shows the correct annotaw x/b -xik+ w)r0 j7g7zprz)zction of the alleles for blood groups?

  Which of these statements are true for alleledmm -8d ,r7 zdbgvn1pu2y5iy+ s?
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 anaee eg8xwqqgk-6 at ,13umia and the spread of malaria across the3 g6u-qweqkt8xega 1 , continent 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 die0:h 5:f iynfetermined by a number of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) colour (P) :fyihef: 0ni5is 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 l3afyr )qnew .*bp.rpb,y,e; genes.

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

Sickle cell anaemia is cau yzof.y44ov8*s vyz+ ssed 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 foree:y qe8ts+l; brown, long hair an;+e:l etse y8qd a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamonuu8 zxqq9rb) r3xn;zxz*a.j .d-shaped seeds (D) is dominant xqz38)9zjb x a quu.xn ;*.zrrover oval-shaped seeds (d) and 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), e;k/exovw1 x- long 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) was carried out on the offspring.w; vkx e-xe/1o



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 t.yt xgqozc 7ts6l++o3x3p6 qbhe inheritance of the condition shown in the pedigree chart b6tsqb. p6gl zo +o3 +cqy7txx3elow?

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

  Which of these statement1ta 54p(aj o5xcif-j*3 5rlm0 qqq )ua. bpqzzs about genetic 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 trai(bmzln zk* : *j ba;(aeyf-k8cts 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 pedigrd, ib3o, k/qjxdco/f* j-4a2oh5 cfvd ee chart is X-linkedc/jbx o/h3-fid25 4av dd jf,qook*c, recessive and not autosomal recessive?

  Different species of living organisms have different numbers of genes cx n.y 2k qt3wz+ov5l(bywz o x;.e;wi;haracteristic to them. The table shows the estimated number of genes for five species. o5 vy (w w;tzox;n2e;z3l+ix .wbqy.k
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 character,phs 5: iwz(ldistics 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 statem s ,5z:dlwiph(ents was correct?

  A biological male with hemophilia and a biological fe e55jt1yo1g4 wwku y0(4wrtk emale without hemophilia have a daughter without hemophilia. What are the possible genotypes of the daughgwjo1rk0ek4w5w (5 e1y uty4 tter?

  A dihybrid cross was carried out between two sunflower plants (Helianthus annuusy-/kb:h0f fh:x,shq 11a i0q. w aekxx) to see if the genes for seed number and seed shape are linked. The critic xaf0whehb :skf,h.-q0 kx1q1 :/yx aial 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 parente( 6w xhu3ma0ss with blood type A and blood type B can have a child with blood type O. awh3 0sux 6em(

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

3.Explain the role of inheritance in genetic diseases.