A man and a woman have a daughter and a son. Their daughter has normal vir+8(a/e .qhkz,+q zvmz b qa/qsion, but their son is colourblind. Which one of these(qqkbva rmzz.qhq,z/e/a++8 genotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somz j1u* zawf( c:jv:hwtqg-,j8p2, y ipatic cell in a human male?

  There are two alleles for flower colour in snapdragons. However, the resul ju1acwj7h /h56 kh-xnt of a cross between two heterh65knh jjc1 -u7a/ xhwozygous 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 ej sv(qi8--x (2f wiapcorrect definition?

  Which of these statemen 6f(50o-zkqciqnt1 p nts is a correct definition for a gene?

  The diagram shows a pair of homologous chromosomes b56 uy;,o5dw6rrhut3ldu qt ..

How many loci are shown?

  Two individuals, heterozygous vy nyeq1ket5r*;ox6. for a specific trait, were crossed in an experiment. Which row shows the expected phenotypic ratios of the offspring resulting fry.;e *nqy51 tox6ekvrom this cross?

  In some animals, the agouti allef6 qhhnxn7v)6bj w -x)le causes individual hairs to have a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who are heterozyb7j vnn qh)6)6x wfx-hgous 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 inwf4zi.0pd o*9(b1nis7 p7rhrw emg/bdividual pea plants was either round or wrinkled. The results of an experimental cross yfinbp(g1.0/rwe bz ih9*wr4mo7 sd 7p ielded 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 melanogacikh(-k69 bwr gg *:dyster) have 8 chromosomes. How many chromosomes are in a fer-* 96r ghki(:w bkcdgytilised oocyte of a fruit fly?

  When does the random orientation of e 5sd2d3+o )bfeucw.thomologous chromosome pairs occur?

The majority of the g0-8yvoxik l-jenes in the human genome have already been mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows vko8xj 0 -iy-lone 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 definitio f-ik u:0 rdp(w;k/wqen of linked genes?

  The diagram shows a karyogram of a brown male rat (Rattus norvegicus). Which arv( xp lfn.q uq):l/2i;dskxu. row is pointing to a pair.(;)2 ldisfvk:/x.uuqqx lnp of autosomes?

  Mendel observed that there are two possible variat3z5pbh8fabr +ions of flower colour in pea plants, purple and white. After a genetic cross, the ratio of 85pzb+rhba 3 fplants 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 chil2cyg6s6 . xbhuu1,eggdren born in London in 1991. 2 .cb xughugy,1ges66

  Which of these traits is an example of continuous variati a)1aiqzg cl3.tom x::on?

  Which row correctly describes diploid and haploid cedmu jg-:9vnx)v1 s yrgk8+ cw)lls in humans?

  The following table shows the diploid chro tbwj;np1htb:)6 q)sjmosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused bk.:mgy0 kemvy xk5.-pkln8 yn oe-i..y 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 tyiq9z4a; t hxk;7rx1o zpe A had a child with blood type O. What are the possible genotypes of the biolog4h1o9 k;z 7aqz;rxxi tical father?

  Which row shows the correct annotaac2 iu/xg7 cr3tion of the alleles for blood groups?

  Which of these statements 1.)jjm g5r dmgare 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 cell anaemia and the spread of mau 2m 1m8jv0reblaria across the continm2uv8 jm10bre ent 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 przewalskiifek43f9tqra.;gv7vu v ec60 l), fur colour is determined by a number of genes. Brown v7v ugqcfe63vtl0 .9kfe4ra ;colour (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+pvad9tv /,qc0i+et 9zbo. cj genes.

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

Sickle cell anaemia is caused by the allelvv pop3*npn, 1e 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 sh;jh6f zqo ap9isp8/b0 ows a cross between a male cat that is homozygous for brown, long ha9hia8pfs z/ 06;opb jqir and a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allelex*r0c bhfpcs ne7*o,.m )mq9f for diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) 7 e)b9snom 0rmcq*xfc.h f,p *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 porcellu ofr6 uj,xlzy;8 xxw0 gx916iis), long hair (L) is 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 pigsxjox giz y0uxir198l ,6;6f wx 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 *;y0f kzbccm7n in the pedigree chart below? b0mz f cyk7*c;

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

  Which of these statemenz. jmr4hhp n+7ts about genetic 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 polyges - 6w;vtz0mngnic traits 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 /rxo;i+ c7 6 yqucxi 8.pmwtc(of the disorder shown in the pedigree chart is X-linked recessive and not autosomal recess/o+t cxri;.m(pixw6 8yc7qucive?

  Different species of living organisms have different numbers of genes charo0 juzq2fd9h lz) rb 2)xi*ml;acteristic to them. The table shows the estimated number of x2o 0zl*9if)u2zl jdhmrb ;q )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 charx./x1/s wj h9jlck8t-fx8 zbbacteristics of pea plants, including flower colour. If the pea plants Mendel was studying c/8txj-81w f/. ljhbbxck x z9san 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 biol xx)o xq/)t51b c 7z:sm-7t1jetikanvogical female without hemophilia have a dxqnkx1amcves /)7-tbx5) o j tizt: 17aughter without hemophilia. What are the possible genotypes of the daughter?

  A dihybrid cross was carried out between two sunflower plants (Heliajwqnqis):g*/qjvwl;s1 511i)a d da w nthus 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 s 1q a ;nad5w)jv1wd:q/iq1l )s*jiwglevel was 7.82. The calculated value for the chi-squared test was 10.05; what does this indicate?

1.Explain how parents with blood tyjwj 9idz4cd5)pe A and blood type B can have a child with blood ty4dzi95jjc wd )pe O.

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

3.Explain the role of inheritance in genetic diseases.