A man and a woman have a daughter 6ia/v 6mxn dq1and a son. Their daughter has normal vision, but their son is colourblind. Which one of these genotypes could be correct for the biolog1 va xi6/q6dnmical mother?

  Which diagram shows thdv(8 kl.s(*rf97fqhnrkcf y9e sex chromosomes of a somatic cell in a human male?

  There are two alleles for flower colour in snapdragons. However, the result of ac;(dqu)+a aw 88ya jgk cross between two heterozygousjd8kyaca g8)(+u ;aqw 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 thj :13osu *bgpmbi1k mr3u 9ol9e correct definition?

  Which of these statements is a correct defin/ h2r1pe8bkha8jp 9 hy5kfj/pition for a gene?

  The diagram shows a pair of homologous chromosomegj -lw3 *p-ndts.

How many loci are shown?

  Two individuals, heterozygous for a specimiha/aoe1 ;8d h9 kkpr;8n h*cfic trait, were crossed in an experiment. Which row shows the expected phenotypic ratios of the offspring resulting from this crossnkh/ ;81;koc* eprd8a hmah 9i?

  In some animals, the agouti allele causes individual hairs to have a bande2g* yyy53c 5ni s8cr v 3zkxckh)0u-uyd pattern. The non-agouti allele causes hairs to be a single colour. Individuals who are heterozygous have hairs wit3uc)0 3ryysv25 kc- hnyky z*xi5u g8ch 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 was either rowmvii;;vk 3v( und or wrinkled. The results of an experimental cr(vi i;mv w3k;voss 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. H6 cm)em0lmm6g ow many chrmm 6cm)m60l geomosomes are in a fertilised oocyte of a fruit fly?

  When does the random orientation of homoos-an +z0zt k4logous chromosome pairs occur?

The majority of the genes in the human genome have already been oaq xs778b sguq v3.wn )sm(k2mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one representation of a homologous pair of chromosomes. 3s ox(uqs8 .7s2k)gaqm7 nvbw

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 linke4 c, feensc n,o5:lj4+ xim7ndd genes?

  The diagram shows a karyograml *7yc6bkr1iklr1k a. of a brown male rat (Rattus norvegicus). Which arrow is pointing to a pair of aut*a.k1 krl 1lb yc7ir6kosomes?

  Mendel observed that there are two possible variations of flower colour bba)k o i 3)xz ui1rp9uvm8+4pin pea plants, purple and white. After a genetic )ixi8p9zv 3+4)ouu mbarbp k1 cross, the ratio of plants with purple flowers to white flowers is 1:1. What were the genotypes of the parents?

  The graph shows the frequency of birth weight of children born in du4ihfbg7a-4dn 3c/j London in 1991/bi nfcda3u dh4-j47g.

  Which of these traits is an example2 jx+6+m iqnzh of continuous variation?

  Which row correctly tr-wa5 ka8x8 kc2f))t i rn+yhdescribes diploid and haploid cells in humans?

  The following table shows the diploid chromosome0m/ yo(lrlr*eg)yw( r number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a re96r7k yw) pkewcessive 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 type O. What are thsqf dn+ib 4k1x93g 9gce possible geno +gb93k cs1 id9xf4gqntypes of the biological father?

  Which row shows the correct annotation of the alleles for blood9juq0x(p:o edxf 0 /km groups?

  Which of these statementg* c zf8yos.bx1i uci;t 5i4a9 vt.5gis 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 ce z 1 kh)4yxi8nl/ cvntiwfr,kf)z:1t6ll anaemia and the spread of malaria across th6/fv ykn1hixw irc :41,n zz8)lttk) fe continent 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 nu 18oiflcl8) 3iphv de,mber of genes. Brown colour (B) is dominant to sandy colour (b) and,v p3l d18l8 fh)icoie 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 unlinked gen27o8 cgny1j53 -mxdkanyqb,rg* ucp2es.

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

Sickle cell anaemia is caused by thv8sugs, ba(vwe :8dfq1; yf tjg :2u*de 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 thr b c(i.jog cy/9)w*vps:.up yat is homozygous for brown, long haicw oi 9cy/b)(prpy .j.v g:*sur 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-shaped seeds (D) isuh7z o jf1sj2mq61+ :xzuc,n m dominant over oval-shaped seeds (d) and the allele for long seeds q+mm hjj zusnxuc2f oz17:6 ,1(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 dominant5i/cse/a mh +s to short hair (l), and curly hair (C) is dominant to straight hair (c). A test cross was carried out between male he +m/chiss5a /eterozygous 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 pedigreh lsuwl:l )mb4t2 -65r jwnumjas3:8 ge chart below3mll)t2:l5s -swhg6 mjuwbru48 :jna?

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

  Which of these statements about genetic disorders6;x hvw cjg86p 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 normal distribuhecpmb/q)qzwiiq5+1 6k 2 x n+tion.

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 pedigreu i68;4lehq1vp gidxf 4i-4:ne q+quze chart is X-linke inuv 8q-uel4e fihq64z1+gpiq:xd;4d recessive and not autosomal recessive?

  Different species of living organisms have different numm9zd:ght-, l 7;a5t zflx 3geybers of genes characteristic to them. Tz zlgmtt5lh-:d7afyg3 ;x9 e,he table shows 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 characzx05k 5w ;/otedgp6knoae co1+:0c z steristics of pea plants, including flower colour. If the pea plan 5e10o:tn cwg ;e+ka0o5p xk6osz z/cdts Mendel 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 hemops7 x t6(ihsg,s.0:mw 2)f tx kgdhr6jwhilia and a biological female without hemophilia have a daughter without hemophilia. What are the possible genjfst,h7 k 6(s.xm :ht)iw 2gwx s6dg0rotypes of the daughter?

  A dihybrid cross was carried/ l ncuwqv dcb4h:232e out 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 level was 7.82. The calculated value for the chi-squared test eb:hcqn2 vluw/cd243 was 10.05; what does this indicate?

1.Explain how parents with blood type A and blood type B can have a cxo n en/a:ny7;hild with blood type O. x/y ane:;n7no

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

3.Explain the role of inheritance in genetic diseases.