A man and a woman have a daughtrcb ryd /t2k)vfia 2g25/k1 f)2wrmk eer and a son. Their daughter has normal vision, but their son is colourblind. Which one of these genotype rrea /k2g/ y)id1m2r 2kfcv twk2)f5bs could be correct for the biological mother?

  Which diagram shows the sex chromn/ hru*9puzo k 9f8k.rosomes of a somatic cell in a human male?

  There are two alleles for flower colour in snapdragons. However, the resun e + 7gu+l:fhv*txo3olt of a cross between two heterozygous plants yielded oeovxh3+lg+: 7 unfot *ffspring with three different observed phenotypes, red, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to the correct def) hnu5vgq1 r ;3:b,p weisrw3pinition?

  Which of these statements is a correct definition for a gene zp3- ;ume5b8is8ckg h ya;k8f?

  The diagram shows a pair of homologous c,ardwf) xso/, hromosomes.

How many loci are shown?

  Two individuals, heterozns2 0hstqu)l)y6l /tyh 0jx g;ygous for a specific trait, were crossed in an experiment. Which row shows the expected phenotypic ratios of the offspring resulting from ;/0 j6 t0y2yghnlst )uls)qxh this cross?

  In some animals, the agouti allele causes individual hairs tj.aj*qtq0s . it1s3rfo have a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who are heterozygous have hairs with a banded pattj*q. iqa0 t3 f1t.ssjrern.

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 individuaeox1,cckg5d qw7k5c ub8nk-ljj6( l ,l pea plants was either round or wrinkled. The results of an experimental crossu7 5 kj5ejb-qklc 6 x cokdgn1wc,,l8( 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 chromosomes. Hqrpd m4 dj)cg2dsx;/ ,ow many chromosomes are 4gjmp /r)c;dds x ,dq2in a fertilised oocyte of a fruit fly?

  When does the random orientation of homologous chromok xv9s8y smx7+)au)al/nsnf,some pairs occur?

The majority of the genes in the human gaahy sks;c851pp(; rw enome have already been mapped, meaning the exact locations of thsaprwk ; 8(s1pc; 5ahye 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 geneh6ss a wx6a*qgyb +7zg5a-d+5 4gg eqd6wnmk3s?

  The diagram shows a karyogram of a brfy*czr e)xs,(own male rat (Rattus norvegicus). Which arrow is pointing t(rfe)yc *x, zso a pair of autosomes?

  Mendel observed that there are two possible variations r+ry dappluitqk3.7:yt* - +q 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 w-r i+: * u+pdqayt 3p7ytrq.klere the genotypes of the parents?

  The graph shows the frequency of birth weight of children born in Londog,bd5y4v.n to fet f.h*/uu)dn in 1991yu.gv dt5*dh 4untf,e/o f.b).

  Which of these traits is an no:j v-w r ob4(6fo;lp67ibuy)x4f miexample of continuous variation?

  Which row correctly descrv* 9ryn 0u*wumibes diploid and haploid cells in humans?

  The following table shows the diploid chromosome num7:3ls ,uclut wb p)(tober of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive allele .+l dq y(7t,3qcbdy9skvp /ew(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 type O. m (gb.qu;,n szWhat are the pqmgu,n;s.z(b ossible genotypes of the biological father?

  Which row shows the correct annotation of the alleles for bqkzc4hwb4);iz 9w,o 8xtx0v n lood groups?

  Which of these statements are true for allst gp5beha+/ ;h 8pyq6eles?
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 ct2uv6) nr2c8s hr 9 -lffmp8sof malaria across the cnmr8p)sc8-2 csl2h fu 6vf9rtontinent 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 przewao2yx0 8d rp*fukyp l9:lskii), fur colour is determined by a number of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) colourdp :y8o0k*lux p2ryf9 (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 between7euq+k .d2/i ebv9rh q linked and unlinked genes.

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

Sickle cell anaemia is caused by the alleleb j.s(pv;2gu j 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 . pkmz6biy:i9* -g hkma male cat that is homozygous for brown, long hair and a female cat t:*yi9 6mk- b hkgp.izmhat has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinal/e: 1ee d *p5q:e0/bu kb ctyc2sczfv-e), the allele for diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) is domvf5e2k:pq-*/cb:duys 1 bcze/0 eetc inant 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), x/wu0w:k/jk)/ qbgfhlong hair (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, k jk): //bwh gux/fwq0curly-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 zj3zvd i23 ya5in the pedigree chart below? 3adjz5y2 z3vi

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

  Which of these statements l()z7-d zoa.zc yehv:about 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 nopi* 8vctiokv 4,/ mdkrx:cd7 e9hj),srmal 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 shogf4a:.y2c kvf wn in the pedigree chart is X-linked recessive and not autosff:k2va. cy g4omal recessive?

  Different species of living organisms have differen ptofsbx +q.i ep:o630(4wfvu t numbers of genes characteristic to them. The table shows the ee6fiu3o tf (s0vb:+pw qpo .x4stimated 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 characbeiz/;v ue6 /m 1rgne, +3it*n)lctlyteristics of pea plants, including flower colour. If the pea plants Mendel was studying can only be white or purple and ;+lg,zmec36ileb n /v 1*te)tynr i /ufollow the rules of Mendelian genetics, which of these statements was correct?

  A biological male with hemophilia and a biolopzn20 8h/e l r)6 xv.vuuu/.obbxv(m ogical female without hemophilia have a daughter without hemophilia. What are vuv/ .0r) . h(eo6xmxb 82zvo /nlubupthe possible genotypes of the daughter?

  A dihybrid cross was carried out between two sunflower plants (Heliax;vnt q.3jcgmnv(.-xjpt; p6nthus 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 chin 3pcvjj pqxxgtv6.. ;(tm -n;-squared test was 10.05; what does this indicate?

1.Explain how parents with blood type A and zakg v q:;hq+1blood type B can have a child with blooda gqz ;:h1qvk+ type O.

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

3.Explain the role of inheritance in genetic diseases.