A man and a woman have a daughter and a son. Their dau 7as)jbvf /wyp .o-)usghter has normal vision, but their son is colourblind. Which one of these genotypes could be correct for the biological mother?usv p7)-y.wf/bo s)ja

  Which diagram shows the sex ckn// kx-)m da1catx:a hromosomes of a somatic cell in a human male?

  There are two alleles for flower colou 25gfnu(jaavi 6g*:gab- d5z0zs9v yvr in snapdragons. However, the result of a cross between sv aj b9z5g au26yv(5:* zvi-and0ggftwo 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 to the correct definition?uw f*y6mfzty/ 5n8 g,j

  Which of these statements is a correct definition,ek/vx0se m ir) pkuqjw1*6:j for a gene?

  The diagram shows a pair of homoloeg1tuv ,yabmkx 2zxy:v)8y*.)k+ b mkgous chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specifi1 37 x2jdli s-yit4ex3d60gdwem0uwo c trait, were crossed in an experiment. Which row shows the expected 3jg ods64 m1 u t7dx3we0yiide-lx2w0 phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti allele causes individual hairs oyiolooq03+mq7 4m-dto have a banded pattern. The non-agouti allele causes hairs to be a single colour. In4+ylmoo3 -o miqdq o70dividuals 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 individual pea pl(xz+mk 2 ygnjq5z71fj9a4v y tants was either round or wrinkled. The results of an experimental cross yielded 315 offspring with round seeds and 105 offspring with wrinkled seeds. ag4mq(7y9zy2 kj+ ztn1vfj5 x

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

  Neurons of the fruit fly (Droso,pm1 elss wb14phila melanogaster) have 8 chromosomes. How many chromosomes are in a fertilised oocyte of a fruie pmwl11b4 ,sst fly?

  When does the random orientation of homologous chromosome p*e -k,w ie.mces5 l3n5+kspjaairs occur?

The majority of the genes in the hum5)s65v elu*z m x(8,hhbj hgs+igo0b can genome have already been mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one representation of a homologous pair of chro(5hv shjlg6i,0gxe so8b*cm b)uzh+5mosomes.

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 link cygm04v,l y,r 0dp*ixed genes?

  The diagram shows a karyogram of a/a(x4fa c-zhr+xoqmw;a f /o - brown male rat (Rattus norvegicus). Which arrow is pointing to a pair of autachaf r a ;qx- +/wo/-mxzf(4oosomes?

  Mendel observed that there are two0;j.c6ckpr4s9o9fjodr p y 2g possible variations of flower colour in pea plants, purple anddj 92 cp9rr.oc0ys 64g; kpfjo white. After a genetic cross, the ratio of plants with purple flowers to white flowers is 1:1. What were the genotypes of the parents?

  The graph shows the freque *w7agtvs r y4*e0lk6xncy of birth weight of children born in London in 1991.4vlsx0 7* gw6yrt*kae

  Which of these traits is an example of c6.mu56-t uaee4dfrbg ontinuous variation?

  Which row correctly describes diploxcp7 ow3l5aa3 id and haploid cells in humans?

  The following table shows the diploid chromoss v)wa0s gp/a4p.ofz-ome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive alyr3 ngf0rt9w)::w xyblele (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 tyuf3).-zg0)we)ave* s bm e o: we)dymhpe A had a child with blood type O. What are the possible genotypes of the biologicaey)*ee wz0h :)-mwg fseo m.)av bd)u3l father?

  Which row shows the correct annotation oer31y d0ai/qv f the alleles for blood groups?

  Which of these statements a7jd)o dr):rg3a it,z1 zhs v6are 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 and1fsg;,g bpq *ycp1x2d the spread of malaria acrossdx 2,q1s 1cppyg* b;gf the 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 przewalskiiy/j (s73h egl8iosxy :), fur colour is determined by a number of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) colour (P) is d(hse l 7ojs:i8g/yy3 xominant 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 linke7 sld au,paz t:t51ez,d and unlinked genes.

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

Sickle cell anaemia is yw 1lqn7( i1zrcaused 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 cro72uqfhdyfrybq l 3 0:-ss between a male cat that is homozygous for brown, long hair and a female cat that has black, shorf2l0 r3qudh y:f y-b7qt hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamond-shaped seeds (D) -6h1 wzooyy9ais dominant over oval-shaped seeds (d) and the allele for long seeds (L) is dominant over short seeds (l). 6ozyhw-1 oa9y

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 w i:np65qcx )nvv -6leto short hair (l), and curly hair (C) is dominant to straight hair (c). A test cross was carried ne c:6-vl nwi)v6qp5xout 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 shown in the pedigree c./:bele jdut4 fti:pcp)q 9 2ohart below?etqi tp:) 2 9cu ofjb4/:ldep.

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

  Which of these statements about genetic diq5 5dp gl-wm)fn)6ip dsorders 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 5* knhzjt5 k y r 1edkc20,8exj/qxcm4normal 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 tjwh : u8od.c4zhe disorder shown in the pedigree chart is X-linked recessive and not autosomal recessive.8ojdc:uh z w4?

  Different species of living organisms have different numbers of gewul 5+jru*hgm27 ggp 9nes characteristic to them. The table shows the estimated number of genes for five species. g+ p2jgu7ul9 *5wmrhg
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 plantex: wvg63ro+-n7ogbe s, including flower colour. If the pea plants Mendel was studying can only be white or purple and follow the rules of Mendelian :v -ge3w +gboo7r6x engenetics, which of these statements was correct?

  A biological male with hemophilia and a biological femgaht/ac(uni 0gc :(.pw wqpw) /9yt: ox+vs,wale without hemophilia have a daughter without hemophilia. What ar(g/0,wg x+ awih):scp9o:wup(/aw tncq ytv. e the possible genotypes of the daughter?

  A dihybrid cross was carried out between two sunflower plants (Helian/fk(m z4snh*a thus annuus) to see if the genes for s *kazf n(sh/m4eed 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 t4blql45.ho xw7q rs 0rype A and blood type B can have a child with blood type Orbx4srqw0ql45o 7 .lh .

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

3.Explain the role of inheritance in genetic diseases.