A man and a woman have x p9rl*qf j64fa daughter and a son. Their daughter has normal vision, but their son is colourblinf*fpx6lr 49qjd. Which one of these genotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic celz3ft02z qg iy-gu 92kpl in a human male?

  There are two alleles for flower colour in snapdragons. However* 41cpshx kzgui.tm jb.8r,-g, the result of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red, white and pink flo 48g.,zmux* ck pit.j g1hs-brwers. Which is the most likely explanation for this observation?

  Which keyword is matche qf95h :do )gnwsd*zim.:,uvu d to the correct definition?

  Which of these statements is a correct defiltq8vyh7b9r 03 : psspnition for a gene?

  The diagram shows a pair of homologouk8j y*qzj.aac0-v m3w s chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were stznq j2g,;b, k3oo+pcrossed in an experiment. Which row shows the expected phenotypic rat otp;obs+qg nzjk ,,23ios of the offspring resulting from this cross?

  In some animals, the agou vjtn*m;og j) jo40,gz *aae6jti 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 hairs with a band)04j onv*j ;j agezmta*6og ,jed 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 was eituzqd 1jo 2qcw7is-tiskh5dt1:1k1d k/,nmb0 her round or wrinkled. The results of an experimental cross yielded 315 offspring with roui1zq ond sk b21dh5,0qdiw k-:/s umkt1tjc7 1nd 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 melanodkb s 56jgm6.jgaster) have 8 chromosomes. How many chromosomes are in a fertilised oocyte of a fruit b jm6ds6gk5j.fly?

  When does the random oriejw07wrxwbgv6e7jpb0n z7 3 *tntation of homologous chromosome pairs occur?

The majority of the genes in the human genome have already beenw/o8 )a m62w7mv bnhpy mapped, meaning the exact locatn/8 6vay7 2opww mh)bmions 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 lyocpi, f1ok jj7 z(+86-plqjyinked genes?

  The diagram shows a karyogram of a brown 7wj 5mip1ic ldj04us2 male rat (Rattus norvegicus). Which arrow is pointing to a pair of autoiml120 j 4w j5sdiu7cpsomes?

  Mendel observed that there are twohrfx k9 w;jpm3kt- -lw70 lnu* possible variations of flower colour in pea plants, purple and white. After a ge w-0l-pk9mljwk ;uft h7xn3*r netic 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 weightzesl,,06q (iiiury 0 m of children born in London in 1991.lreiu 0zsqiy0 ,im 6,(

  Which of these traits is an example of continuous vrdgqy6sdb*m5m z7e 54 ariation?

  Which row correctly describes diploid and haploid cells idh kuu/jj7/m) b: fj0qp45hc hn humans?

  The following table shows the diploid chromosome number of a rangf+*dtovzzj+df48 / /k x okeb5k5w 4hae of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a: c6+eqg ng;d9lsb;to 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 bl3(8rv ugpuc*d ood type A had a child with blood type O. What are the possible genotypes (cu*g u3 d8prvof the biological father?

  Which row shows the correct annotation of 34oko;pgtxle 0 zc-fs-p. . crthe alleles for blood groups?

  Which of these statements are true fp a2j,txyor7x- 0o0zt 7*-cinyk6 v ador 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 esn+p3 ,hs x :xv,o uzt+1ds6d2cve0rcell anaemia and the spread of malaria across thet:+dd,pvesh30s zcx+ 1vn6 s2,uox re 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 prz/b7*w k6p+jx o(gezytg pa:n5(* rtpfewalskii), fur colour is determined by a number of genes. Brown colour (B) is dominant to sandy colour (b) and an ombregp5okz jp*wbta:67* x/tre+yn( g(p f (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 betweek395uvoemdhr :fj 88wn linked and unlinked genes.

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

Sickle cell anaemia is cnqt 9 j(kshm01aused 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 homozn0n m*qxslj s 0rm,)u:ygous for brown, long hair and a female cat that h*sjxq,m)nlrn: 0 msu0 as black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamond-shaped seeds (D b4afn8-; ;hh6y mmeed) is dominant over oval-shaped seeds (d) and the allele for long seeds (L)e6 b4 e;y8-mafh ;nhdm 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) is bjeqyqi838q13*, qz/ucu; a;iufpwm 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, qqw;im3qb;aj u/ ,fu188p* iyz uq3cecurly-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 theuh-g,wgq t2d- 7/lq( r d mocgoy-nt8(ynn.b2 inheritance of the condition shown in the pedigree chart belowwo-(gdh odr/t nnq.l,g -cy - 2tmu72q(8bn gy?

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

  Which of these statements about genetic disorders is/are corm0*yul1r)*+ta bdp r1yi fas2 rect?

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 a5k15ft h smdhrubk 6 05f(fo-m 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 op3ud; jlgy 4,tf the disorder shown in the pedigree chart is X-linked recessive and not autosomal rece4d pgy3;j, tulssive?

  Different species of living organisms have differ3pcum/u8p g0k1 .0ego hiodwpg *2cm:ent numbers of genes characteristic to them. The table shows the estimated number ofg8:gdowppu.1cpuc oe/hmgi032 m k*0 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 flo t;g9bj oyv;le v dw(j,e*5+ l0-dzeiywer colour. If the pea plants Mendel was studying can only be white or purple and follow the rules of Mendelian genetics, which of these statements ;g vdt( 9ywd* jv+e; e5j,0zy- ibollewas correct?

  A biological male with hemophilia and a biologic(cws +zq5)pa gko d1/cal female without hemophilia have a daughter without hemophilia. What are the possible genotypes of the z+ck(15s apdwqco)g /daughter?

  A dihybrid cross was carried out between two sunflower plants (Helianthus annuusu2rusi1a7m)xcnife9+lc3 q /f 4 eq c8) 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 calculated value for the chi-squared test1ie x 2ffla974umsicqu8c+ n3 erqc/) was 10.05; what does this indicate?

1.Explain how parents with blood type A and blood typr /n9w/di+6i u3cznpx e B can have a child with blood type z9 +u36cdp xi/in /nrwO.

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

3.Explain the role of inheritance in genetic diseases.