A man and a woman have a k0 jqsf64/y udgf1g td(qq7-h daughter and a son. Their daughter has normal vision, but their son is colourblind. Which one of these genotypeqhdq7kj6-gqt0fgs4 /f( duy1s could be correct for the biological mother?

  Which diagram shows the sex chromosomes o6 h50cb,ytu*jr/ sknqf a somatic cell in a human male?

  There are two alleles for flower colour in xm,s/ 7x/;,y2xn jml1(:gvkc d5xgiq0 m ga tosnapdragons. However, the result of a cross between two heterozygous plants yielded offspring with three different /gcjo my/ vx 5xi:tknqa1gx7;,m gx(m0d,2s lobserved phenotypes, red, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to the correct definitionn 4.).h e*syc+ndu3eqour6ho ?

  Which of these statements is a correct definition for a b.6c8jteab1 y) x.varl8 / m oit*yum8gene?

  The diagram shows a pair of homologous chromos*c0yiu-le (qsomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, wew8;; jpw4 8rmgqj)derre crossed in an experiment. Which row shows the expected phenotypic ratios of mrepw;w 8)r4 ;j jq8gdthe offspring resulting from this cross?

  In some animals, the agouti allele causes individual hairs to have a bani2 .bby)h2e6d1due 9 2is9uqypnxk*d4ls: f b ded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who are6hfs.4di bduy9ilb)eyx2 12 sb d:p*n 2uqe9k 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 individual pea plants was ,z9vzvisuq:if.zkh2(dl+ l:either round or wrinkled. T+zf h( lv liz:kq:s,i9 .d2vzuhe results 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) have 8 chromosomes. How man48 fz .e*n06e ukim;r hz0xy/an 3toxty chromosomes 3 za.etn;xhrt6*8fik0ex0/ ou m z4yn are in a fertilised oocyte of a fruit fly?

  When does the random orientation o0y) dq/ wzd+k/r mrs+tf homologous chromosome pairs occur?

The majority of the genes in the human genome have already been mapped, mean1f ;qv1-h*udbldd 0;dv-ttx iing the exact locations of the genes*fdddlv d11; x- hbiqut0tv -; 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 xcuivyl6.bdv w-oh/.g3at 3ec- (w 49 z7asmkof linked genes?

  The diagram shows a karyogram of a brown male rat (Rattuvcw s;dqf5;3th3, vv0h cuhf35vnq-a s norvegicus). Which arrow is pointingau, 3- v 3;f cs5vqhc0n35vh;qvhwdft to a pair of autosomes?

  Mendel observed that there are two possible variations -..,glz pmsp yof flower colour in pea plants, purple and white. After a genetic cross, the ratio of plants with purple flowers t,.pl msgpy-z. o white flowers is 1:1. What were the genotypes of the parents?

  The graph shows the frequency of birth weight+drehx9fdk i 85q6 tvgw c44;z of children born in London in 1991.9x4ehd+c54gz vd witrk8f6q ;

  Which of these traits is aj*sg6if- bg -:dhqca;n example of continuous variation?

  Which row correctly describes diplokl 4tceal.:1:aptp0 ek. 2gslbaw;2f:/ sn izid and haploid cells in humans?

  The following table shows the diploid czt h/gs(a:yi:hromosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive allelfm8e )(t6 on5y8 s-kei m.lviye (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 .rav3wsc l25bag pf85type A had a child with blood type O. What are the pol8 r5b f avwp3ag.c5s2ssible genotypes of the biological father?

  Which row shows the correct annotatio/q96c:j7ixbwoip- m on of the alleles for blood groups?

  Which of these statements are try e53n7jp3hz)):i psyaj b ao e2bj(y,ue 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 o6x n63ip.(xxin **vbc0sgk hqf malaria across the continennv g.6*0pib*x x 6i3 n(hskcqxt 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 8n-yhh )reg weja pd16iw/0;t by a number of genes. Brown colra0 wwt-hp1/he e jd g)6y8;niour (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 linked and unlinked gcrd 6ypso 5pez77)x b-enes.

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

Sickle cell anaemia is caused by the h;wq5rjcs b0w bwf:7fc+fog4 m 3n04gq1g 1nr 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 cross3:, 4duplgtzq:0nyqcd o-vx+ between a male cat that is homozygous for brown, c-4n0 ytxv: oqdpdg+3: q,luzlong hair and a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxac5.;cmt wca zx-k5wyqcyu s -5)um officinale), the allele for diamond-shaped seeds (D) is dominant over oval-x-a.zq5 c5mwcy yt;uk5c)s -wshaped seeds (d) and the allele for long seeds (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) .q s8ju;d u+tris 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, curly-haired guinea pigs and female short, straight-haired guinea pigs and a chi-squared test (χ2) was carried out on the offsp.udjqts ;u+8r ring.



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 gir-:9;o wy:d n2do,uqw-u feshown in the pedigree chart be:w9 2g-u-r:d ou,;ifo dqy nwelow?

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

  Which of these statements about genepfw xv3ro :v9;tic 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 trait6t7:zl t5p we, wxd4tws 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 d8hf/ g,2rej 8fgt)va hisorder shown in the pedigree chart is X-l8fjrt agfeh, g/2v)8hinked recessive and not autosomal recessive?

  Different species of living organisms have differg d 7vcu+k8 cds,6d;lvent numbers of genes characteristic to them. The table shows the estimated 6dcc +vsdkv gd;87, ulnumber 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 charactt+-a t .kervfq5n**fferistics of pea plants, including flower colour. If the pea plants*ft5 f. tkre v+afqn-* 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 biologigxrgf: i:gy,ths d/3kn/,pd(cal female without hemophilia have a daughter without hemophilia. What are the possible genotypes of the d (/ :g,k3ngtdrfp gihy, x/:sdaughter?

  A dihybrid cross was carried out between tjlp+qfeg 5z x81jbj0* +g( 1spi(gtiowo 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 was 10.05; what does this indi(p+1iz(ogj1ixjb 8 + qg0tjpfgl*5es cate?

1.Explain how parents with blood type A and blood type B can hp o:d2zb2io5c o+q m.eave a child with blood type e5: pdo2i.+oz2 ombcqO.

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

3.Explain the role of inheritance in genetic diseases.