A man and a woman have a daughter and a son. Their daught pi (0wrbvwkkh68hla/n1 /ycz0i a).s er has normal vision, but theci )nrwza.lhv1h86k (/0/abi0kwyps ir son is colourblind. Which one of these genotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomerae 12k. y 9cxpd4pe x3p:k;tps of a somatic cell in a human male?

  There are two alleles for flo:rwi5n5 i/c 5kbt4qw nwer colour in snapdragons. However, the result of a cross between two qrk5:5n5ibw/ w ni4tc 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 v.a+:4ewcqet to the correct definition?

  Which of these statements is a correct definition fn5dm 1xd;y8r8lg3tcs 0q +kcmxoafx u(c:p4)or a gene?

  The diagram shows a pair of homologous cw vet 53ev, w4p:fg;sohromosomes.

How many loci are shown?

  Two individuals, hetp hwk;rj /ngy:tsy0yq5g5.g, erozygous for a specific trait, were crossed in an experiment. Which row shows the expected phenotypic ratios of the offspring resulting from this cros.:yg n k g,q50yj;hprgsw5yt/s?

  In some animals, the agouti allele causes individual hairs to have a bandel3g 85bx j4*umgmws: e-f5ex)hq7ki od pattern. The non-agouti allele causes hairs to be a single colour. Individuals who are wfu 5*43xeo 8m xl)ek: shgjgmq5b-7iheterozygous 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 indijig vcri*.9 5nvidual pea plants was either round or wrinkled. The results of an experimental cross yielded 315 offspring with round seeds i9gi cnj v.r*5and 105 offspring with wrinkled seeds.

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

  Neurons of the fruit fly (Droso4twax -ise;/z phila melanogaster) have 8 chromosomes. How many chromosomes are in a 4 a wz;txse/-ifertilised oocyte of a fruit fly?

  When does the random orientation of homologous chrooe8w103h m 9x 6 qodg1y/ckz3p9tj nucmosome pairs occur?

The majority of the genfna:xvhn g8v5nq/s * :es in the human genome have already been mapped, meaning the exact locations of the genes on5/n hgvn:q 8s*f:n axv 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 gene0 yj,6c gjhpp k4zk lj1 ;v+::dqpb;bws?

  The diagram shows a karyogram of a brown male s3mm 1 0 rkfbwmtpjzzsq:b 0+x-,1qb5 rat (Rattus norvegicus). Which arrow is pointing to a papq:1bj0sq- mz mxtz b f rb+m5kw01,3sir of autosomes?

  Mendel observed that there are two possible variations of flower colour in pjjvy1h8xq 9r1rkpzs8 +sfv9 msc g;4 7t9phu 4ea plants, purple and white. After 1v h 1pysq9grc4xtzvfpjsrmk7su8 4 ;8 +j99 ha 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 -ps (sulbj35y qw *xq5+.y ovoof children born in London in 1991b syq. 5s xu+5 l-o*ypq(ovwj3.

  Which of these traits is an example of continuous va+u2u0zgu)* ki yz/lh uriation?

  Which row correctly describes diploid and haploid cel1 0mlcn wm :-vi3k/ytjls in humans?

  The following table shows the diploid chromosome 69y;xo d9bb/hl h;sfwd 6 lk;:se(hhs number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a a5 juyf+/zu2w 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 .gksukr,zewukxo5l)- 52f5 ptype O. What are the prpug5l,z fe k5)5 ks oxu-kw2.ossible genotypes of the biological father?

  Which row shows the correct fmjc. d4h8 c/*kvvaz( annotation of the alleles for blood groups?

  Which of these state9owbj+hl,iqxy;5pwlun 69,h: g5zc noi6(s i ments 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 anaem)1 tnhtj(bqn tt2 - hkt2jk4;oia and the spread of malaria across the contj4q(hkk tohtnj ;1t)2tb2-nt inent 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 dzj,vpm+,j03ayus 9r oetermined by a number of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) colour (P) is 9joy,mu0ap+ s ,j3 vzrdominant 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 linx cf9 .ic-bay4ked and unlinked genes.

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

Sickle cell anaemia is cij8t5sf0-w0perk3 p(eem+zz rmdq /-aused 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 d/*i s+legro h4 lxnk+ hzp625,mskg4 is homozygous for brown, long hair and a female cat that has bl/i2hxo,nlgg6+epls m4ks 4z kr+*h5 dack, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), i*l.rx -.vr fcthe allele for diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) is dominan.r*xfr .c -ivlt 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 mco b6sl8ggpk:ol w: w;x2.f0hair (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 (χ28s;fo wxp0o k cl6mw:b2:gl.g) 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 conditiva49jm,/9+. e6nacfifljx njku86zy on shown in the pedigree chart beijuzc+kv9ay6l6.x4jn 8/je 9,a ff mnlow?

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

  Which of these statements about genetic d.djp nt6,3 3snon64 f 1cg-ycwyzlo /zisorders 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 clds 4ot0dly8,an 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 fp) hps6-9xdudisorder shown in the pedigree chart is X-linked recessive and not auto6)sfp-hud9 xpsomal recessive?

  Different species of living organisms have differenhy1 fd/ ea n3hc60tv) h)njl;ut numbers of genes characteristic to them. The table shows the estimated yh6dn cea; jv/t31) nf)ulh 0hnumber 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 of pea pq/ r exq1(czi*lants, 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 srq*x (q1 cez/itatements was correct?

  A biological male with w- wzi cc3t.+jhemophilia and a biological female without hemophilia have a daughter without hemophilia. What are the pot3 wccziw-+j .ssible genotypes of the daughter?

  A dihybrid cross was carried out between two sunflower plants (gji px1xs9 g*t9 l.i ;cyolrb9k93r9g 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 significance level was 7.82. The calculated value for the chi-squared test was 10.05; what does this indicay9rg .9xg1g;9ij9sll3pcio9 *b rktx te?

1.Explain how parents with blood type A and blood ty mn-w8nb7f;df pe B can have a child with blood type Off nn-8bdm;7w .

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

3.Explain the role of inheritance in genetic diseases.