A man and a woman have a daughter and a son. Their daughter has normal visioddz/6as.5 qqgn, but their son is colourblind. Which one of these genotypes could be correct for the biological mzdgd/sa .6qq5other?

  Which diagram shows th: t.nbtly05x qe sex chromosomes of a somatic cell in a human male?

  There are two alleles for,:r 2d:wacu mji0j fv. flower colour in snapdragons. However, the result of a cross bet.i:j ,rm:jcdu fw 02avween two 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 f3e2 * 3.okwjto 2rnehto the correct definition?

  Which of these statementnyxf13qgy f *iqy.(8h s is a correct definition for a gene?

  The diagram shows a pair of homologous chromop c(( er2eca1quar:w dg5 x/*nsomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were crossed in an ext0d3o1x. w +-jakf h 1xvzs,ddperiment. Which row shows the expected phenotypic ratios of the offspring resulting from this a1 1h.x-k3 0dz vo+ tsfxddjw,cross?

  In some animals, the agouti allele causes individual hairsggfyo( ny :34f dohqy*l*2da e;apu7 9 to have a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who ar3df g*dg4el2of p*yo7a:aqnhy;uy 9( e 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,k/mk /-ear3lc xl(pr shape in individual pea plants was either round or wrinkled. The results of an experimental cross yielded 315 offspring with round seeds and 105 offspring with wrinkled pka erll3x// rk-,c(mseeds.

Which row in the table below states the most likely genotypes of the parents?

  Neurons of the fruit fly (Drosophila melanogaster)g,+1pq+(pj ,j fxcc0k.pfyiu have 8 chromosomes. How many chromos.p ckf1jyi,, x pu(gf+0+qpjc omes are in a fertilised oocyte of a fruit fly?

  When does the random orient0p0byy69cqzots +j j 67fk,kration of homologous chromosome pairs occur?

The majority of the genes in the human genome have already been mapplyv9* fo9 txjitl*4w+k; xl;hed, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one representation of a hoxo4wt; h lk *i9lj*yl9+f ;txvmologous 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 gemzgujpakgl 7o15pcxh;tu 6uhf9 9 5/7nes?

  The diagram shows a karyogram of a brown male rat (Rattus norvegicus). Wnk3 2;7a afy4ddc(j(jxt jss3 hich arrow is pointing3;a(2 dtdc3 7a4sfknxj jsj (y to a pair of autosomes?

  Mendel observed that there are two possible variations of flower coqcg , yv5+fz436 l z*cnreqfu7lour in pea plants, purple and white. After a genetic cross, the ratio of plants with purple flowers to white flowers is 4cveqfu7zr, cfq+6* z ylng 531:1. What were the genotypes of the parents?

  The graph shows the frequency of birth weight of c/ysc( gx,4odbz*;)mg uei-yl hildren born in London in 1991l, uczb4xs d)ymyo/;*(-gge i.

  Which of these traits is a+ubddl* h35p 5pg2t zcn example of continuous variation?

  Which row correctly describes diploid and haploid cellhibzr nkt-7n)dbyh 6a g3y:90s in humans?

  The following table shows the diploid chromosome number of a range liw,/3(0 b kfgvbl4du g9pr* zof species.

Which of these statements is correct?

  Sickle cell anaemia is cause qly1x518bfc ad 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 a child with 172:czm)sqhhxc , ej2/arpia-d2m li blood type O. What are the possible genotypes of the biological father?7e hzp2c :i h/s2ij lm2 d-1,)mcaxraq

  Which row shows the correct annotation of ,h1-8efrxq(ih rw *dh k 3zzrj0 gjy/,the alleles for blood groups?

  Which of these statements are true for alleles? 5eum7 x2.fho *pti+sfo4hzf2
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 oshiw 5sryk i(226cox5f sickle cell anaemia and the spread of malaria across thr(5i2ss5ox 2ic 6 ykwhe 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 (Ee .j jm*84kfhbquus przewalskii), fur colour is determined by a number of genes. Brown colour (B) isek4*.hfjj8m b 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 l.dy./fap, z+zs bg -zuinked and unlinked genes.

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

Sickle cell anaemia is caused by the allele bg u9a qawy ++gorg ml)w:wa,r)rwlc 6i78,w( 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 cros,)0cx3jhhw 3jyp cf-as between a male cat that is homozygous for brown, long hair anhc)jaj-pw xf 3,ch0y3 d 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 *5 pm umf222q* f1 waeieo3fse j)+sqdseeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) is dominant ovefm*pdf+3)a*sm2 ie2qq 1 e joswufe52r 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) ,q4 y gexrf2r(is dominant to short hair (l), and curly hair (C) is dominant to straight hair (c). A test cross (er ,qf2yg r4xwas 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 thp:v 6ja , x,s92z/bnmr3 qbidme inheritance of the condition shown in the pedigree chartj9zpm ,d/q23bnb :v, r msia6x below?

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

  Which of these statements about genetic disorders is/areb*lvgc- q-s3l 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 c*akm .)/pgm e5kzoe y2an 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 shown in the pevd2n8 5 5mx e(a8apolqdigree chart is X-linked recessiln 5ev2amq8a (8o p5dxve and not autosomal recessive?

  Different species of living organisms have diw v p f9 u+jempj7;kt*v+m1v4kfferent numbers of genes characteris;vemm*jf+kk+ j9v17 p4 twvputic to them. The 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 characteristics of pea plants, including flower colour. If *m t(tr 6i-oy.g +ehohthe pea. oyet-g *+m(h6otrih 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 hemop4 yq dku4.qc0ihilia and a biological female without hemophilia have a daug4q4ku0dq.i cyhter without hemophilia. What are the possible genotypes of the daughter?

  A dihybrid cross was carried out between two sunfd2/; p,gec+n1rek rii lower 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-sqr+c;1g2ekirp/ d, ine uared test was 10.05; what does this indicate?

1.Explain how parents with blood type A3yu.66s yyjq9rs)9y ak;al f iziq5+ p and blood type B can have a child with blood 6yzy q +q y5j fra9lsaiui;3. 9)pkys6type O.

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

3.Explain the role of inheritance in genetic diseases.