A man and a woman have a daughter and a son. Their g1dsj-hq k je( g.oh-s,)vac8daughter has normal vision, but their son is colourblind. Which one of these genotypes could be correct for the biological a8kj-hh,e)s - gg( djsv1oc.qmother?

  Which diagram shows the sx )7ak h dlnx:slh.x,4ex chromosomes of a somatic cell in a human male?

  There are two alleles for flower colour in lavj+ +to zq27snapdragons. However, the result of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red, white and pink flv7+atzo +2j qlowers. Which is the most likely explanation for this observation?

  Which keyword is matched to the correct definslhm c/*pmw.b7 lq k6 ln(e,6tition?

  Which of these statemezhi7/ :0cq4 kby z1omwnts is a correct definition for a gene?

  The diagram shows a pair of homologous chr5 s5u+xc8r ifo;3h hqdg/8dblomosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific traiup6 /qb2 rrjv/t, were crossed in an experiment. Which row shows the expected phenotypic ratios of the offspring resulting from /2pq/r6buj vrthis cross?

  In some animals, the agouti allelols r+ q 2q76juelvr)1v1k b*we causes individual hairs to have a banded pattern. The non-av u2wk1l1sl)qv7b o q er+6*rjgouti allele causes 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 voc2ai* t g6r.individual pea plants was either round or wrinkled. The results of an experimental cross yo ci*agrv2. 6tielded 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. .;n,ca6n e x)4hewhej How many chromosomes are in .)jw; 6,n4hene eaxhc a fertilised oocyte of a fruit fly?

  When does the random orientation of homolkl*ptplo .t h tq,-dwe/.nd8. ogous chromosome pairs occur?

The majority of the genes i47fwkvk.ic 5 ;ftgl 8ln the human genome have already been mapped, meaning the exact locations of the genes on chromosomes are known. The7.v5w; clf kil g8ktf4 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 lin knmvp s..p5*uked genes?

  The diagram shows a karyogram of a brown maleb.idr-axx8,/p d 6 lfu rat (Rattus norvegicus). Which arrow is pointing 6bpx8 i.d fd/,rxl ua-to a pair of autosomes?

  Mendel observed that there are two poi bvgtv8*m u* cwj/4(ussible variations of flower colour in pea plants, purple and white. After a genetic cross, the ratio of plac8b4 vgtuv *ijm/(wu *nts 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 Lfxskw 5*9 jzv:ondon in 1991. zwf sj:* 9vxk5

  Which of these traits is an e n5y9g -+ubwv,ia2ke7ue j 1cjxample of continuous variation?

  Which row correctly describes diploid and haploid cells in humans? vrk;v5i5l*ja,miju 1yt9 y t+

  The following table shows theqfuj6zh (5ie4- e:nob diploid chromosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is ca8bmqg qjak4n9ow1-h .used by a recessive 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 axnf3i fr,fz8zf4; e8n child with blood type O. What are the possible genotypes of the biological fath8,r8;4 f nx nzz3fieffer?

  Which row shows the correct annotpt5c4:f peb3n 1bc 2tyation of the alleles for blood groups?

  Which of these statements are true for a:o, m9xvrp (lglleles?
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 o;ga vu2,wp.wyf sickle cell anaemia and the spread of malaria across the continent ow,uywa2 gpv .;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 (Equus przewalskii), fur colour is determined by a s.dwu/ lr. ipibh1jt se.* *1lnumber of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) colour (P) utws1 l r/l.id*hpe 1 .si*bj.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 unlh+ iyl( (pv2lxinked genes.

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

Sickle cell anaemia is caus / .jn:; 6d ft8eij2hz-o5vi;n lwaaaied 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 for br.a-z; n na2ophpnt ;*o sqcgmdab*570own, long nm*cbzop 2 ; ;7q0- nd5snpa ghoaa.*thair and a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale),u4;na:5z*iuxdmu /kd 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 seeds (l). m ax/4u:ud5d ;ki*unz

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 sho0b7rq(*lovon n s-4jfrt hair (l), and curly hair (C) is dominant to straight hair (c). A test cross was carrofo q7(jsv *n- blr40nied 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 cid 7qhsgo1sfpx , 22i6ondition shown in the pedigree chart , is 2pqog2dfh17s6ixbelow?

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

  Which of these statements about gegoma 1v)5ll ,5xhc2 efnetic 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 normal distrib1p q 4as02.gghpuwriz3xu8 t1ution.

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 pedigree chart t.jp/g- n fu0whg9q m(is X-lgnp0ghw.9juf q t/-m (inked recessive and not autosomal recessive?

  Different species of living orgv0/tg uaze.c tbcw e5 d*p((k4anisms have different numbers of genes characteristic to them. The table shows the esttedwa t(c/ .z 4k5pu0 *cv(ebgimated 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 char k -buay9 uyg(awu1/b6acteristics of pea plants, including flower colour. If the b1/ a -y6ba9gu(ykwuupea plants 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 hemophilia and a biological female without hemoprfo- si +zj*.bz l0jf1eq*tg7vu9ej 6hilia have a daughter without hemophilia. What are thf eubq*jz r *+tge.1l0zvo7s 9ij-6j fe possible genotypes of the daughter?

  A dihybrid cross was carried out between two sunflower plan+:z;h p : hqyl9.xwyr8x*7) kxibgxnkts (Helianthus annuus) to see if the ge xwkn*: 79lqhx +;i:xgz hxp)b8. kyyrnes 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 indicate?

1.Explain how parents with blood type A and bloodo w;cd*x8b(aomx3n4k type B can have a child with blood type O. ko4*8 b xmxacwnd;o(3

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

3.Explain the role of inheritance in genetic diseases.