A man and a woman have a daughter and a son. Theirdxv86rc4 eof.u h fj6p 2a9do8u75hic daughter has normal vision, but their son is colourblind. Which one of these genotyp8 9d8uho2hf7ucvxa 46d6 jo5cr.eifpes could be correct for the biological mother?

  Which diagram shows the sex chromoj39qa (8c97yxzp xar qsomes of a somatic cell in a human male?

  There are two alleles for flower colui:26vtz3 82j nmd)tvh rcvp 13 dpwa+our in snapdragons. However, the result of a cross between ttd2 v316ua +:ch2intz3v8m vprpd)jw wo 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 to the correct de5pzogs7h e vwyi e)8*8t)7p bkfinition?

  Which of these statements is a coamf4 r 378xe5iqw:pdp rrect definition for a gene?

  The diagram shows a pair of homologous chromosom8jg;c0u ijpw ;es.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were crossed qyr ko 8xqp5n/a*;ao,0a.gohin an experiment. Whiyo5oa/;rqhnagqpko0 ,8 * ax.ch row shows the expected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti allele causes individual hairs to have a bandedblf.9u9vjd/f9n ffd 9 pattern. The non-agouti allele causesdnfv9b9u j.fdf lf99/ hairs to be a single colour. Individuals 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 in 9zk 0xzhk6-nrhwp3(y 7k f1nzdividual pea plants was either round or wrinkled. The resultsynnh f zkzhk-9 6k(1r3wpx70z 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) efq teq92 i4fd ,o*e/zhave 8 chromosomes. How many i*f o/te,d e4f9qzqe2 chromosomes are in a fertilised oocyte of a fruit fly?

  When does the random orientation of homologous chromosome pairs occur?i :cdf9t; w 6xavh9ipj8c0q5p7p doy7ahru; 6

The majority of the genes in the human genome ha-(uyc. kyl-1kxkz6)y0jwf fz ve already been mapped, meaning the exact locations of the genes on chromosomes are known. The diagramfy 6 k-w0c) yky-u.l(1z zjkfx 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 correct8kjx5 s)qp/ed9:ch uf)a 3e7ph *gqvm definition of linked genes?

  The diagram shows a karyogram of a brown male rat (Rattus norvegicus). Which aruz,ua,z3ufwu(:a lc6 c l5dg- row is pointing to aaz(d,auf u c5 w:g3cll 6zuu-, pair of autosomes?

  Mendel observed that there are two possiblz8t7r a1ocyvl/o.8u0 xf( suce 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 1:1. What were the genotypes of th(lu 0 ocz/xvr.f 8t7u8c1o ysae parents?

  The graph shows the frequency of birth wey v*cq:n q(ig(ight of children born in London in 1991.(*i qn (qvyc:g

  Which of these traits is an example of continuous pa tj e2)0o5jdi(uav*variation?

  Which row correctly describes diploid and haploid cells4 urlx.6v5y dt in humans?

  The following table shoi*dwv-hcn(k 7m 6oimzn3 ry*;ws the diploid chromosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a re7qt0;k-csi0j +o4z,vahh,j,y z z bfdcessive 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 svhu/ f*9ss lr0kd3i+with blood type A had a child with blood type O. What are the possible genothds0*+9fslui v/k 3rsypes of the biological father?

  Which row shows the correct annotawn sges uvmw-:in/e3 if)x9 fp/1 yiwzd* 11l7tion of the alleles for blood groups?

  Which of these statements are tr-) 7qw 0zys slqu34 g:kbqn*unue 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 spread wpt(8 op ytsjl9rd5p3m0h /d:of malaria across the continent of pjrt0:th(y39 w5 mlspp8o d/ dAfrica.


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 i) p 5o91ush ck ((/knl; uvgk(vhycq7ys determined by a number of genes. Brown colyh5)c7 1qukvc9; gu(lyh/(n kk(ps voour (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 l1 :i lu82hoodninked and unlinked genes.

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

Sickle cell anaemia is caused by the allel*;d *sqix567bpm 0hf zo/dd vke 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 aclhx.)l0j83pj .szc)jg u(+s hk pn1g male cat that is homozygous for brown, long hair and a female cat that has black, s)z j 83pch(sk n+hlgj cs1j. .)xplu0ghort hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officin yl(:c7daawt2 ale), the allele for diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) is dominanttl:a wa(y 2dc7 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 dominant to short hair (/r8gm+ oby et8l), and curly hair (C) is dominant to straight hair (c). A test/ro+mey gbt 88 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 show kfeh(y 95lt)+hk.r(- ivlrg ln in the pedigree chart beg)5(vk+h.rl ykflltr(hi -9 elow?

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

  Which of these statements about genetic disorders lgsaq;cx4ily 84j 10vis/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 top+f+u 4gpgz( raits 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 inheritance of the disorder showni)ck);s msng3 in the pedigree chart is X-linked recessive and not autosomal rcsnig)3;k) m secessive?

  Different species of living /(l eks ss)+y yv/ll7gorganisms have different numbers of genes characteristic to them. The table she(ys) /gsls lylv+/7 kows 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 charac ugmmoxa/) :i91 ,gubcteristics of pea plants, including flower colour. If the pea plants Mendel was studying can only be white orbgix,9)amcu g o:m /1u purple and follow the rules of Mendelian genetics, which of these statements was correct?

  A biological male with hemoph/w--k / barxlvp7ex 2, yt/ksiilia and a biological female without hemophilia have a daughter without hemophilia. What are the possible genotypes of the daug x //saik/-bpt - ,wr2yxevl7khter?

  A dihybrid cross was carried out between two sunflower plants p.l5 zb7m:jplh oq3o9zy+ 6 ks(Helianthus annuus) to see if the genes for seed number and seed shape are linked. The critical value for z zyspb:pm7q .h635olo+jl 9k 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 with blooddxw.*xh( ow (n7ts s7k type A and blood type B can have a child with blood typexwsst((h nox .w7 k*7d O.

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

3.Explain the role of inheritance in genetic diseases.