A man and a woman have a daughter )*:mrt zwek7 mn0e/bvand a son. Their daughter has normal vision, but their son is colourblind. Which one of these genotypes c0ee)mbr/* m kvnt z:7would be correct for the biological mother?

  Which diagram shows the sex cz/m ew)mvf( ,fhromosomes of a somatic cell in a human male?

  There are two alleles for flower colour in snapdragons. However, the resulk3 4)x 4*h*biogp vlm7 (fvwxht of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red, white and pink flowers. Which is the most likely explanation for this observationplo) 44 vfkhx7h*vmxi3*wbg (?

  Which keyword is matched to the cot9lv y/jwzrhe/z+co4 k*t(;b rrect definition?

  Which of these statements is a correct definition for a gene pe 5m9x2st6lp?

  The diagram shows a pair of homologous chyszvpgd5 4nv bu/61*p romosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were crossed in w/ 3evwf+m *(7czqz0zep s e1van experiment. Which row shows the expected phenotypic ratios of the offspring resultings q z/7zme*31(wz+0cv efwp ve from this cross?

  In some animals, the agouti allele caab(hhc2;c* rg tl,fo, uses individual hairs to have a banded pattern. The non-agouti allele causes hairs to be a sin;rthl,b ha, g(f *co2cgle 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 ind/du5,d myt 7d vgs(/84ihppxaividual pea plants was either round or wrg7/ahv/sdyxpdut,m4i5 d8(p inkled. The 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. au 9vbbv .;zmx7jr j./How many chromosomesbjbz amjrv/ .v u;x.97 are in a fertilised oocyte of a fruit fly?

  When does the random orientation of homologous chr1 t*-lukah+b pomosome pairs occur?

The majority of the genes in the h)idd jydk;teecl6 17 d1vt89l uman genome have already been mapped, meaning the exact locations of the e jl)tdd9v1d8c 1ie67kl dy;t genes 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 of linked genes?yg pnj6 4fppjgrw of*1:jf i.62;eq3s

  The diagram shows a karyogram of a brown m3es0 f,zh*salcis/:y ale rat (Rattus norvegicus). Which arrow is poisyfi, *c/ sh0l3ze s:anting to a pair of autosomes?

  Mendel observed that there are two possible variations of -gagcs*.uy , oflower colour in pea plants, purple and white. Agg o-u,ya.c*sfter 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 frequency of birth weight of (-zm4to epdh j6z 43nichildren born in London in 1991. hno4-p(34e6jmziztd

  Which of these trait-t qoad(l 8r7ohuy37 gs is an example of continuous variation?

  Which row correctly describes diploid and haploid cells in huma;8 1) x(:j l ypfnsyb/j.lneekat0a 4lse-q(rns?

  The following table shows the diploid chromosome number of a r x 3ul2:lmh 0ws68bu)+ lh(90,bcb xfoomsf uyange of species.

Which of these statements is correct?

  Sickle cell anaemia is v2 r3q+of1il ba7 unumv:+po(caused 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 c9(q-t*y ay93 z vqofbx1.j fe9gdcs:child with blood type O. What are the possible genotypes of the bi9 .ty9xgcd* bqf s:e-qcfvo j 31y9(azological father?

  Which row shows the correctg d n 3*qwn4dy*12hr3tqnfl-z annotation of the alleles for blood groups?

  Which of these statements are yv2ped6(xnzu0r20e e) ckkf .qw/, hhtrue 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 inq,ok k0e7ys)a cidence of sickle cell anaemia and the spread of malaria across the continent of A) sa,o70ekqyk frica.


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 przewalskipdse h.j1;q h,i), 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;p1qsj d hhe,. 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 ge:z g d;, dmxl1pxp0(lhrkd,;o nes.

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

Sickle cell anaemia is caused by the allele3 5z(i*qulvfe 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 be: rmar+wx*. .fujokp7 tween a male cat that is homozygous for brown, long hair and a fe*x.+: 7umjpka.or rfw male cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), th57ut* tjtlfa* e allele for diamond-shaped seeds (D) isfluta5 7t*j *t dominant over oval-shaped 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) is dominant to sho uyuyjts .e.)5rt 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-hairedsj ty yu.)5e.u 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 5y0 d2wae9v .9up vus79th;w-y wniduthe inheritance of the condition shown in the pedigree chart belw2n w p.udwyah i-e 5tuuvyv;79 s909dow?

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

  Which of these statements about genetic disorders is/are correcmi f f lg j02jzzkj17s7ry.8n.t?

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 normal distributionh*kw c2:0i )dtxzqn, l) rn+bh.

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 pedigree chart ijry1l n wk3j9 88juty/s X-linked recessive and not autosomalj 3w/y9 j81 uktjnrl8y recessive?

  Different species of living organisms have different numbers of genesj )*5fx/v zpo6itpd+ lntl,;q characteristic to them. The table shows the estimxz;pl fvq5ti,j*pt)n /d l6o+ated 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 pe.al2 g8ymn5d a*vntn.v: *ycta plants, including flower colour. If the pea plants Mendmy dg* lva.5t2c:*n.n8yntva el 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 biological female witho:.yi 4-b et2bzielh8 gut hemophilia have a daughter without hemophilia. What are the possible genotypes of the da -4bhl.ezebi g 2t:yi8ughter?

  A dihybrid cross was carried out between two sunflower plantd23cwyuwps rz, 7qr 6t89 jj6zs (Helianthus annuus) to see if the genes for seed number and seed shape are linked. The critical value for 76wzpc d jrwj9qturzy286 3s, 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 type A and blood type w ono(*y/meq s(knd98B can have a child with blook*oe(8( /dnom wnsy q9d type O.

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

3.Explain the role of inheritance in genetic diseases.