A man and a woman have a daughter and a son. Theigk13 m lb9ksn)r daughter has normal vision, but their son is colourblind. Whin9lkgsk3)m1 b ch one of these genotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic c;nfnm un*gd w dt *nv7e:y;2ns08op7yell in a human male?

  There are two alleles for flower colour in snapdragons. How c9ag-oxz2bg 1:0m utwever, the result of a cross between two heterozygous plants yielded offspring with three different9z:2atggm w-xcub 1o0 observed phenotypes, red, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to the correct (antfz bn ,y8h(r1 r.mv9/ suvdefinition?

  Which of these statements is a correct definitgznjh 3ukld)ga . 1*)qi44qceion for a gene?

  The diagram shows a pair5+ i*bh03vi-9 wzswu nkzn8e h of homologous chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a r( s+k.9xq6 abaiosg4; 4djsya4u(ezspecific trait, were crossed in an experimentrbse (sg(q6 a4zxau a4j+4k9si o.y;d. Which row shows the expected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti allele cm4 fgp g2ejx44k9v( abauses 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 banded pattekme4 bjpxf92(agv g4 4rn.

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 ix6 k kfqx52 na1uffnkpss4/58ndividual pea plants was either round or wrinkled. The results of an experimental cross y6 xk15f48 5npnss2uqf k/kafxielded 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)gdywmo +b,r* 9 have 8 chromosomes. How many chromosbg d9+yw m*or,omes are in a fertilised oocyte of a fruit fly?

  When does the random orientation of homologous chromosomk 4-m:xk)zfuh1nu 9 cye pairs occur?

The majority of the genes in the z2ihfz )wqyyd q )y(y m+ev2yf; 4,-jihuman genome have already been mapped, meaning the exact locations ofy)(fm+wv y qy- f jy2y)i;z, qdeih4z2 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 linked gene+/gfwpt(rol)o6 few )s?

  The diagram shows a karyogram of a brown male rat (Rattus norveg 1obnrq8f l.g +p-df2picus). Which arrow is poinfd-b2 r+8 qngplf.1op ting to a pair of autosomes?

  Mendel observed that there are two poss8kal ,5z ,cg4/kicbh c) 9cduwible variations of flower colour in pea plants, purple and white. After a genetic cross, the ratio of plants with purple flowers to white flowers is )kc/abgh9 4,k 5lc8cuizc d,w 1:1. What were the genotypes of the parents?

  The graph shows the frequency of birth weight of children born 8 b/oy3a h):3 dhpj 3lfo/bgokin London in 1991apbl /oo3koy3 /)bd8g3hh :fj.

  Which of these traits is an example of continuous vari4lxyi) p1j)glation?

  Which row correctly describes diploid and haploid cells in humaf 9u .6 ayl 5ls94dsvru0uabm8ns?

  The following table shows the diploid chromosome number of a range k dh/(pqsutvsun7- ,8q0udq 8 of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessivo u tr-1ql7wmt1yjxs 06q8m-bc/h6 tte 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 had9wh8w guq3 4od a child with blood type O. What are the possible genotypes of the bioloh qw3dgu wo984gical father?

  Which row shows the correct annotation of .et j818 vcvakthe alleles for blood groups?

  Which of these statements are t.krp q2la dv.6rue 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 2:ni5 u; tgwfewmfg4rj/zq43 spread of malaria across the cont4j3twfzg;/u5gi :r4meqn 2 fw 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 determi3x4odd5 jyth-ned by a number of gen yo5t4- 3jddhxes. Brown colour (B) is dominant to sandy colour (b) and an ombre (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 unlinke() wp5bpdk1csd genes.

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

Sickle cell anaemia is c98o 21 yz/y anrys3 nbcddw1ue( (7zvqaused 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 homozygous fc/yx 6ry.dc2l2mqd h, or brown, l/xldq26yyr .,2 m dhccong hair and a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamond-sha0s) o v9vzq lq+ppo0wr/;jh6mped seeds (D) is dominant over oval-shaped seeds (d) andzvo0+ v0l6pr/m9 sjqo qph;) w 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 dominan /;ubeulbqgv:i r52z.k:v vr ;y dn2o*t to short hair (l), and curly hair (C) is dominant to strv *r;:z25 edin o ulr/ 2byg;bkuv:vq.aight 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 of the condition shown in the rqpeq 1jdqr2 r*9r2s-pedigree chart beloq2q rje19rp- s2r r*qdw?

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

  Which of these statements about genetic disorders q37sldhae rw5n ),/hh 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 traitsrq vx w3t;wh)6qhbh.tzir z1r3)g -w5 can 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 inheritancif*03qt4cm8fc a o9gdz(f i,xe of the disorder shown in the pedigree chart is X-linked 4i mcio3qc,td8 fx (0f*f9zag recessive and not autosomal recessive?

  Different species of living organism//v (ga8r(cjqnd y5qx p)f: eas have different numbers of genes characteristic to them. The table shows the estijaa(/f yd: rgx8/pn v(5e)c qqmated 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, including flower co otzy3(f4 l.db dx0vqx)py 6x+-obm.u55n vaulour. If the pea plants Mendel was studying can only be white or purple and follow the rules of Mendelian genetics, which of these statements was correct6dv+zvxap (n)lou5x b ymxt.df5y .-304 obuq?

  A biological male with hemopgb:rd q(/ bo0yhilia and a biological female without hemophilia have a daughter0 o(/q: bgdbyr without hemophilia. What are the possible genotypes of the daughter?

  A dihybrid cross was carried out between t.oi5,6 x.k ,(7malnbnodbie3ikq c6qwo 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 level was 7.82. The calculated value for the chi-squared test was 10.05; what does this 6qockib5nax(bni 7,mko.l6 . qei3,dindicate?

1.Explain how parents with blood type A an,6es7xi(o6xk 4ks plo d blood type B can have a child with blood type O. solp,o76k 4x6eixsk(

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

3.Explain the role of inheritance in genetic diseases.