A man and a woman have a daughter and a son. Their daughter has b-o(5em4k 3dpx5q+ ypz.st qonormal vision, but their son is colourblind. Which one of these genotype (yz 5+s4m.xpq5eqoobp-d 3t ks could be correct for the biological mother?

  Which diagram shows th;taii /m,6by4rrz 0ech 5 hg;me sex chromosomes of a somatic cell in a human male?

  There are two alleles for flower7:5 nf/iayule iy e(u; colour in snapdragons. However, the result of a cross between two heterozygous plants yielded offspring with thr7ey; un5luaey/: i(ifee different observed phenotypes, red, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to the 09ml. fmqr qa8correct definition?

  Which of these statements is a correct definitif)v u ryh 65rr*4yhqsh6uh.1son for a gene?

  The diagram shows a pair of homologous w3p. qewv +j k*t(ff2echromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific 7dppw00- anau f ,xsw(trait, were crossed in an experiment. Which row shows the expected phenotypic rat7ua(fwa0w ns ,ppdx0- ios of the offspring resulting from this cross?

  In some animals, the agouti allele causes ind6u.pqp.0g7,huf iv:npj gfa 5ividual hairs to have a banded pattern. The non-agouti allele causes hairs to be a singl ,uu f:5.7piq0 gpgafhjvnp .6e colour. Individuals 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 the seed l94 5fcko00f ax1pxmushape in individual pea plants was either round or wrinkled. The results of an experimental cross yielded 315 offspring with round seeds ankaf4 x1 pf0lxmu509cod 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 melanogast )5d4ctg.ve weer) have 8 chromosomes. How many chromosomes a5. egtvec4d )wre in a fertilised oocyte of a fruit fly?

  When does the random orientation of homologous chromosvva4 a3 i/,il9*dda j0j)o;yuv k ;sweome pairs occur?

The majority of the genes in thej/f:nhf73s l k-e f0bq human genome have already been mapped, meaning the exact locations of the genes on chromosff 7: j besfl3nqk0h/-omes 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 linkedmd-k8g: 6f;q fphk(d i genes?

  The diagram shows a karyogram of a brown male9(x8v dma8zqt rat (Rattus norvegicus). Which arrow is pointing t mva(xz8d t9q8o a pair of autosomes?

  Mendel observed that there are two possible variations of flower colour in pea pe f wmjba(0x (feun17(lants, purple and white. After a genetic cross, the ratio of plants with purple flowers to white flowers fef(0 w(mx ubj1 e(an7is 1:1. What were the genotypes of the parents?

  The graph shows the frequency of birth weight of children bor xkm9bl9dbc8 0n in London in 1991 9 m0bbxkc98ld.

  Which of these traits is an example of contk26*zswkx k1o inuous variation?

  Which row correctly descgu: ztg o*n. n h,wsv(g)7kuq8ribes diploid and haploid cells in humans?

  The following table shows the diploid chromosome number of a rangep4(da.ww a fmg *8ynep +tnq:4 of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive al39 )uhurv9)0 exvkwmt;rk;-4 xp vujt lele (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 3 xolbryx49c *type O. What are the possible genotypes of the biological fa9l*b4y x3cxorther?

  Which row shows the correct annotation of the alleles fq s-q a8t/ 9l(euau d-w )ake9y)ij/kgor blood groups?

  Which of these statements arq h4f)(slp q1ie 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 malariart, y.r3f9b5 l65y;srxhtb lb across the continent ofy slr5f.6 y;3 5,hrtr9tbb lbx 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 przewalsk vtsat.9x.)y(1rqx-+kkugfjwdb; 0 eii), fur colour is determined by a number of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) colour (Pu9g1-t+dxqxke a).rfjvksbwyt (;.0 ) 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 geqd p(6 :btgbb x2v+x;unes.

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

Sickle cell anaemia is caused by thet+ /njc;qqxfr8/v bj ( 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 mu00 fb gw8ckx.ale cat that is homozygous for brown, long hair and a feck.8bxg 00w ufmale cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for(q08xj uxrjnh ni nd,s78 4n/ oi7he6b diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) is dominant over short seen hb0o 8j7n(snj qi7ir4hx8 du6xe,/n ds (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(r8) 0qc bjnmd) 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 femrmbqn dc8(0j )ale 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 the inheritance of the condition shfu)vdereaa ,8)e :k+hown in the pedigree charteer,e)v: a8 uhdfa)k + below?

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

  Which of these statements ay4q,w)g l gof2bout 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 traits can show a e5 +4wdfjq q.u/g/oaljr rq c ,k0fh:0normal distribution.

2.Outline the differences and similarities between homologous chromosomes.

3.Explain why expected and observed Mendelian ratios may differ.

  What suggests that thiq2 9xw of-;cbr4h 9qoe inheritance of the disorder shown in the pedigree chart is X-linked recessive and not autoso-ixo f4q9qbw c9r2h; omal recessive?

  Different species of living organisms have different numbers of genes ig: xh64-m elp6js fp.characteristic to them. The table shows the estimated number of genes for five specixh4fip pg.:-6me6 sjles.
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 3 v gy7ko xwqvy0e6+ pitf(6+upea plants, including flower colour. If the pea plants Mendel was studying can only be white or purple and followu vqyvkx(t60+pe3iyw go+7 6f the rules of Mendelian genetics, which of these statements was correct?

  A biological male with hemophilia and a biological female without hemophilia oy4b3cq 5o*juf h 4.5rv9dlrghave a daughter without hyrc. b*u4g5 495fvohjrqlo3d emophilia. What are the possible genotypes of the daughter?

  A dihybrid cross was carried out between two sunflo+k1/ yyv g 0sd8,uptmhd q,w3lwer plants (Helianthus annuus) 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 signifpw+g1qdy tv/0, l u8 khy,sd3micance 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 chi eo 5clz:g,w8u:uza6uld with blo z,ug:5uewoc: ualz68od type O.

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

3.Explain the role of inheritance in genetic diseases.