A man and a woman have a datkgc0o9w16z +qn5tes ughter and a son. Their daughter has normal vision, but their son is colourblind. Wh o9zwcs e6gttn+5 q0k1ich one of these genotypes could be correct for the biological mother?

  Which diagram shows the sex chromovz9mw ,l96l 0 tdq6kx da+h9i0 4kowrjsomes of a somatic cell in a human male?

  There are two alleles for flower colour in snapdragons. However, rkn ja9n2)7yem xu 91sthe result of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red, white and pink flowers. Which is the most likely explanatioaj2s 1x ymr)9n9u7kenn for this observation?

  Which keyword is matched to the covi0p cc,he7 m,rrect definition?

  Which of these statements is a 83po: ;on bx9uips7rdcorrect definition for a gene?

  The diagram shows a pair ji7stffmgr9*+ pok9 5 of homologous chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were crohfv1 +p;7 dj :1vcw(;a3dn be4kyma aissed in an experiment. Which row shows the expected phenotypic ratios of ca ( f1yi7;n+:43vweaj aph1dkdmbv; the offspring resulting from this cross?

  In some animals, the agouti allele causes individual hairs to have a band )vx-mx0hc6(3xbc bxbug m9rtn7)h+wed pattern. The non-agouti allele causes hai r)uxc-thb+)wgbvxx 09(m3hxm bcn6 7rs 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 in:p ui7d(wqrgskn y1 41dividual pea plants was either round or wrinkled. The results of an experimental cros sugq( 1n1:wdrkpi y74s 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. H-/ze5i3avy *eq yz2gjow many chromosomes *iqz 3y52gaj/e-zve yare in a fertilised oocyte of a fruit fly?

  When does the randomf*nbcvyau5k x(h(8(ecnem hn7u-0z+ orientation of homologous chromosome pairs occur?

The majority of the genes in the humrhacn)sr 93p +an genome have already been mapped, meaning the exact locations of the genes on chromosomes are know 39rs)+rhcap nn. 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 of ,8u+8oi6*sv bwlx o3ag lc a1clinked genes?

  The diagram shows a karyog4x+d3gr cqd5tt20gkc-wpuz;a,+fip ram of a brown male rat (Rattus norvegicus). Which arrow is pointing to a piwxk0r 3;dt g+tfq,2uda 4 -5czgc+ppair of autosomes?

  Mendel observed that there are two possible variations of 1 vf 3)cpa*rzsflower colour in pea plants, purple and white. After a genetic cross, the ratio of plants with purple flowers to white flowers is 1:1.vf r zca)1s*p3 What were the genotypes of the parents?

  The graph shows the frequency of birth weight of children born inoaf h fyeb ,+*rsp7(79 +mijqz London in 1991. si y7qm(pr f+j*haozeb+f79 ,

  Which of these traits is an example of consihwh9/m,y5i tinuous variation?

  Which row correctly describes dip-8 km4vje tb sa7n3c9cloid and haploid cells in humans?

  The following table shows the diploid chromosome number of a r( thil5xkl/af54eff. ange of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recesskzrq+,3 1 xv8qa-yhveive 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 bloodh u2 czpu+n9*z type O. What are the ponz+ 2zph9*u ucssible genotypes of the biological father?

  Which row shows the qr-n36n pwp/1 wkh*wacorrect annotation of the alleles for blood groups?

  Which of these statementi) qwq9*zll /5fchqmo+p -pe ml5,2 hos 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 cell anaemia and the spread of ma5 07voi rn;gurlaria across theg; 5ov7n irr0u 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 nusaed )bgp,* b3mber of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) colour (P) is dominant to one tone ga,b3p *s)ebd (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 linkedn l4j8g 0k5yao and unlinked genes.

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

Sickle cell anaemia is caused by4 jia s(s spp1+i:.mko 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 gevig:q mn0 p./-fmx-a male cat that is homozygous for brown, long hair and a female cat that has bl0 epxvgnq i-mm /:f-.gack, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinalec62k,tfre:3wv +tzp.ar z ia5ig(+o3alwo -b), the allele for diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long se,2i+ gr wft+:(b ec.k p3 5w3zorot6ial -avzaeds (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 ha0oiteu noo5 *n6ca13ng/en xe2. ldh3ir (L) is dominant to short hair (l), and curly hair (C) is dominant to straight hair (c0 td6ago23 1e ico*le/5o nn.enux3h n). 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 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 shownv vaa ym(wj 5zk0o8c)6pe ha50 in the pedigree chart bemov0y(50 jpc6we8hkz)a5va a low?

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

  Which of these statements about genetic disorderslb6+y7 jyup 5e 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 nora;3kq gsx *tw4:b; o2ml5dvztmal 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 disordeapzmxzt8t .0u-q7 - cgr shown in the pedigree chart is X-linked recessive and not aut cm0z.8-pztt - u7xqgaosomal recessive?

  Different species of living organisms have different numbers of genes characte i mlnk-g x6 eedwsm,r.2z(8vm-z n 22r*dskh1ristic to them. The table shows the estimated number of gezr6ksxe mkh-iv zn2(sd2-wg n1 2ldm 8* r,em.nes 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. Iri- y ;gethzv77m nl+ n(gvo+(2kc;mi f the pea plants Mendel was studying can only be white or purpl7g o ktmi cn mv 7(n2y;-lgvri+e+z(h;e and follow the rules of Mendelian genetics, which of these statements was correct?

  A biological male with6nz,je 69vu,4o i9wd ap3qfv5e-sh gw hemophilia and a biological female without hemophilia have a daughte f9i 4wna, gqdev j9vp-sz66h,wue3 5or without hemophilia. What are the possible genotypes of the daughter?

  A dihybrid cross was carried out bemvx03* ru)zi(n s6t hgtween 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)0tn s3rzu6hm*g iv(x calculated value for the chi-squared test was 10.05; what does this indicate?

1.Explain how parents with blood type A and blood type B can r(r)hz8a/h+udus fw5 have a child with blood type 5 8ur+azd(sfw /urhh) O.

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

3.Explain the role of inheritance in genetic diseases.