A man and a woman hacsn7uu nf3p;zbj */:zve a daughter and a son. Their daughter has normal vision, but their son is colourblind. Which one of these genotypes cou*7bujnu zc :/snpfz3;ld be correct for the biological mother?

  Which diagram shows the sex chromosomes fh (70y(evvwqa 1x drfha6ac-/ y4n ,uof a somatic cell in a human male?

  There are two alleles for fximk8/o ,us;kd xi yhihgfp7;, 44.bllower colour in snapdragons. However, the result of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red, white and pink flowyg i 7,4.u/h4d kpslfkbxxi ;m8h oi;,ers. Which is the most likely explanation for this observation?

  Which keyword is matched to the corresfl19h *x x 2ytfvj-(mct definition?

  Which of these statemeyqr1mclzaii(8sq6 iv, , ul6:/z:hcbnts is a correct definition for a gene?

  The diagram shows a pair of hom/uvh( v7+(xbota wii0ologous chromosomes.

How many loci are shown?

  Two individuals, heterozygous for aa8rr +id56for specific trait, were crossed in an experiment. Which row shows the expected phenotypic ratios o5dor8 ra+ir6ff the offspring resulting from this cross?

  In some animals, the agouti allele causes individual hairs to have a banded p 76li zke 6bu0-atfkt,5o1mfpattern. The non-agouti allele causes hairs to be a single colour. Individuals who atla6 5k6 zt1kofpf7m-ui0eb ,re 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 shape in individualb/;;yuts )6-ilzfw i x pea plants was either round or wrinkled. The results;uw6z; bf-tiil) /ysx 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 melanogaster) have 8 chrlj9g jy1dao 42omosomes. How many chromosomes are4 2gy9dja lo1j in a fertilised oocyte of a fruit fly?

  When does the random orietsk+bki .rn kv:rz.z/j-6s* mntation of homologous chromosome pairs occur?

The majority of the genes in the human genome have already been mappe njuni s,o 7o8v5 a4)ca)efft)d, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one representation of a homologous pair of47e n) 8ajcn5)vo foftau is), 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 ot+ l( q5sg,t8ssj;yed f linked genes?

  The diagram shows a karyogra t )7vk/00nxh/b0 nhc1e hgohem of a brown male rat (Rattus norvegicus). Which arrow is pointincbt v1 k)x0e0/ohn0hh/e 7hgn g to a pair of autosomes?

  Mendel observed that there are two possible lu-39eo2sm ybqa3 ke,f;gez +v )f,g;uya b.gvariations of flower colour in pea plants, 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?g o qa+m9,,f yeulkb)eb;efy2;-vz 3.u sgag3

  The graph shows the frequency of birth weight of children ;af8d5db*b zpborn in London in 1991. b; bzf5a8pdd*

  Which of these traits is an example of continuous variapk2qsc 4.tms ,tion?

  Which row correctly describes diploid and haploid cells in hum7ykt0 4 widt6mg4v-4x owvwk :ans?

  The following table shows the diploid chromoso lc paa(8r2mcxdq,b4 5me number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is )pd qg4 r+tls1)haor14 mz k2wcaused 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 a child with blood tnsj0 .v(.u: .arg y agi+nfi,gype O. What are the possible gen.ns( iiafvagr+,n:gg.0y. uj otypes of the biological father?

  Which row shows the correct annotation ok)st1/;ham 1scf2 xs ao,e gp;f the alleles for blood groups?

  Which of these statements k+u7d -mqfde-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 afdvc ko;g+4ee,,9 erwnaemia and the spread of malaria across the continen, e;9cv,k+o dgewre4f t 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 determined by a n e2*d:+8 (qx.aq qy bnlsm)hksumber of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two t*. 2qqh8 l es aqkxys:nmbd)+(one) 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 ane;*jls y -h1uwd unlinked genes.

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

Sickle cell anaemia is caused by the allngtmh8.elr qi4)( cr+t+e)7w, mgofdele 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 v2c vo+g fc45/2qcdgt is homozygous for brown, long hair and a fem5g2cfgqdvov+/4 c2 tcale cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diaw8:)s2s * ;jo ycx ga hjun:go0fyq,poa6lz8:mond-shaped seeds (D) is dominant over oy ca*lz6qoagxwgyf, 8 u: honp:;)sjo2j 8:0sval-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), long hair (L) is dominhdxfn::))7et znkb9l*o6tcq n -ra/nant to short hair (l), and curly hair (C) is dominant to straight hair (c). A test cross was / cd-9o ) 7l:x:t *6knfz)eqh nratbnncarried 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.



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 shwima0*3 m6 w e:6ealbjown in the pedigree chart :b*a jw6laimm6 ew0e3below?

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

  Which of these statements about genetic disorders is/are co.i9rt ea v.2c9p f ycivb((.omrrect?

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 nopc0 1nkvj 9 ,f(ali8t6;u itxermal distribution.

2.Outline the differences and similarities between homologous chromosomes.

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

  What suggests that the inheritadpk iwz*.i c j0vo;axa4b+-+g nce of the disorder shown in the pedigree chart is X-linked recessive and not autosomgv aioax-+dj.b 4p+ c*wiz0k;al recessive?

  Different species of living organisms have different numbers of genes chaiw r5 0:p:0xkkmuq0enpw9se 1racteristic to them. The table shows the estimated number o9nps0i xw k p:0uee1rk0mw5:q f 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 flower colou p,bv-h8s*uvfr. If the pea plants Mend-, 8fvvsh*bp uel 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 hemophili588wyt;5fsgu 20eke tgof 4x urm+ar)a and a biological female without hemophilia have a daughter without hemophilia. What5 t2+gkfrg0ux o4 est85w;f8)u myar e are the possible genotypes of the daughter?

  A dihybrid cross was carried ou0jhf h94yx gd)pa6ir1t between two sunflower 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 significance irh)9xj1gpa064hf dylevel 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 -dpcv2np8w0ix -hg* c 4 jil2rcan have a child with bloodlcg-0p cjx*n48dp ri2i2-wh v type O.

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

3.Explain the role of inheritance in genetic diseases.