A man and a woman have a daughter and a sonch+eh cft+u (mg7ai+;9d, e xb. Their daughter has normal vision, but their son is colourblind. Which one of these genotype+fae, cet7;+iucx mh+9d(hbg s could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somaticb)m s/,x 5dt(u7z qn)zfete+z cell in a human male?

  There are two alleles for flower colour in snapdragons. 61p;s8 m b8cwtccm /tdHowever, the result of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red, white and pink flowers. Which is the most likely explanation for th6cm ;pd1tcb8t8smw c/is observation?

  Which keyword is matched to thoren,3t+v w.u fi7wm2z7y5/vqk an7b e correct definition?

  Which of these state:3ylg , xk( b*7vt esp.mq6kgwments is a correct definition for a gene?

  The diagram shows a pair of homologous chromosomes. ewsi8uqdgm./ t tj ++5

How many loci are shown?

  Two individuals, heterozygous for a specificc +u/t8r u zoq4qzeb-: trait, were crossed in an experiment. Which row shows the expected phenotypic ratios of the offspr-: oe zuur48 c/bt+qqzing resulting from this cross?

  In some animals, the agouti allele causes indi0ae h6 j.z hb: ,yxnq7 vbnyzop;3z*t4vidual hairs to have a banded pattern. The non-agouti allele causes hairs to be a single colour. I aq byj0;npe3hzx zo:b7v 4z,nhy*.t6 ndividuals 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 shape in individual pea plants waxr7*e qlu7+yxs either round or wrinkled. The results of an experimental cross yielded 315 offspring with round seed+xx7 7y l*requs 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 (Drosdnw 8:liw gyax9 .4mh2ophila melanogaster) have 8 chromosomes. How many chromhx a48l 9miwnywd 2:.gosomes are in a fertilised oocyte of a fruit fly?

  When does the random orientationds*j pqy22yu u-s+z+n .pms(z of homologous chromosome pairs occur?

The majority of the genes in the human genome have already be*x q+ s /2/r3wh;cx9oxiucyueen mapped, meaning the exact locations of the genes exr9*q;uyoch3x2 u wx ic/+s/ 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 b9utf:m y18k dof linked genes?

  The diagram shows a karyogram of a brown male rat (Rattus norvegicus). +yx-z(v0i w83k3dmzbtmgk 1lWhich arrow is pointing to axvd ym3i-(z8 gltk+wz1b m3k0 pair of autosomes?

  Mendel observed that there are two poq4q.-oxgunb 5 ssible variations of flower colour in pea plants, purple and white. After a genetic cross, the ratio of plants with purple flowers to white flowers4qg x5bqoun. - is 1:1. What were the genotypes of the parents?

  The graph shows the frequency of birth weight of children born in London in 1991k5) s* (2qeks.t(y rpo rbwda.. sr2 .d5wkrq y (pab(*k.)soet

  Which of these traits is an example of continuous vwg8kg tm-+ rr hwb. /u8g16xxiariation?

  Which row correctly describes diploid and haploid cells in huma,-)sd vl th j48cnm3dkns?

  The following table shows x f8*fuf /xzi0k371z yyplwm, the diploid chromosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a receyzu0n d*y5 5xj 53viz/4hrcdyi/hih 3ssive 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 1-ovx w.6tptv blood type A had a child with blood type O. What are the possible genotypes of the biologpwv.o-tt 6 v1xical father?

  Which row shows the correct annotation of the alleles for blood gr 5-a*dz: uqeh zc1gor0oups?

  Which of these statements are true for b,xg lr.qpg;ia+33)pe a pbjj-a z7k8alleles?
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 t ks ;/xs62w/xo r,vawehe spread of malaria across the continent ovsaw6x ,s/2 wxoerk ;/f 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 (Equusp f66iwc/t9kx r+qbetq 54,r ofr jzr;+gf. 2k przewalskii), fur colour is determined by a number of genes. Brown colour (B) is dominant to sandy colour (b) and an rp,2r cgz5qfx6eqj4f+rr9k /i . k6; ttfb+o wombre (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 between linked and unlinked ge)rhk m,hqc: d)47x9 axgrvgh .nes.

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

Sickle cell anaemia is caused by 0;nw txdq- -3lppat4 plx; 0bcthe 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 mal:qo oefo47r(:zn zd ;pgz8 hw/e cat that is homozygous for brown, owp h; zoq(:fn47o/zeg8dr:z long hair and a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale)mhwxy-f-,db 7t gs5 by;)6whh , the allele for diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) is dominant over short s;-6sx ht-yb h),dmfy 5b7hgwweeds (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 dome0 8ohoauzay p- j)87)v /wxncinant to short hair (l), and curly hair (C) is domivcaoheu a/w08jpy7n-) x) 8oznant 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.



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 ofsxsrho3(5 h39 dvsk (g the condition shown in the pedigree chart3sk(v3rsh 5sdxh(o9g below?

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

  Which of these statements about genetic disorduk:wlg e:t , bw , c5+ffi)s6pjkkq.d5ers 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 zgt,qyznnhc (8 t( hy1,;ez.ba 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 pedigrez6 pt42hks,e(, uskuz+odm8 me chart is X-linked recessive and not autosom ode6u2zkt z+(8ssu 4,mp, hkmal recessive?

  Different species of living organisms have different numbers of genes chch2bq+s4fiwkoi .: 0saracteristic to them. The table showi+bq:s0 .4ci hks2 wfos the estimated number 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 plants, 5.j7swmoen94ketm r6u c n 2ym4vs3 a2including flower colour. If the pea plants Mendel was studying can only be white or purple and follow the rules omr.ku 4m savcewn37en5m2 s269joy4 tf Mendelian genetics, which of these statements was correct?

  A biological male with hga :y-wlwd 1yh3y;gjgayx ad ;3l.-8d emophilia and a biological female without hemophilia have a daughter without hemophilia. What are the possible genotypes o3lya;ywjdy. gg ;a3wdxylh- gd-18:a f the daughter?

  A dihybrid cross was carried out between two sunflower plants (Helianthus amw -liczkx: abd 635j5nnuus) to see if the genes fodm5jbl6w- zca:5 x3i kr 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 indicate?

1.Explain how parents withgsv+nek0 ;jip. e (*a9sz9jcr blood type A and blood type B can have a child with bloodn9ak.9j +cp; es v(i*gersz0j type O.

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

3.Explain the role of inheritance in genetic diseases.