A man and a woman hayqsvq.f )(-ku ve a daughter and a son. Their daughter has normal vision, by fukqq(s .v)-ut their son is colourblind. Which one of these genotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somaw,a4pgbe mxhkh*8;1 f tic cell in a human male?

  There are two alleles for flower colour in snapdragons. However, t +xvfe fz/j0v-dpw:e)he 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 explanation for this observation?f- z:je0/ xvwev )+pdf

  Which keyword is matched to the correct definitionkg6;uo g 5,pilh*)ynnz mc:q 7?

  Which of these statements is a correcqxhs :dwij7ka* z4v- 1t definition for a gene?

  The diagram shows a pair of homologousd2)xx ijd;47e;q do m.rjoci6 chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific traoyfll7-aok d ))+;szl;9ay wsit, were crossed in an experiment. Which row s s7o9 ak)l;afz-sy; )wl lyd+ohows the expected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti allele causes individualazxr10w)6q ea hairs to have a banded pattern. The non-agouti allele causes hairs to be a single colour. Indiviq60x )azare1wduals 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 plants was eith5(b1jypuyiss fu)g kh2 x58u)er round or wrinkled. The results of an experimental cross yielded 315 offspring with round sb21s 55i)xu (hyu)kju fyps g8eeds 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 melanoga.*blry5(sjzn4 rsb3 vgqy( g 1lj5ru6ster) have 8 chromosomes. How many chromosomes are in a fertilised oocyte of a f vusyb53 s(r zyn4(qbl.r1 *rlg5 j6gjruit fly?

  When does the random orientation of homologous f*kp*vjyno(o yn owz l2154p* chromosome pairs occur?

The majority of the genes in the human genome have alr 3 mxvcy6b: mo-qhg2;yeady been mapped, meaning the exact locations of the genes on chromosomes are knownx 3yc :q6-mmygo2; vbh. 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 c9n9sdf2jn a(9a i:cyof linked genes?

  The diagram shows a karyogram of a brown male rat (Rattus x7h:ms,g,gi k(q k +:h+ guvjlnorvegicus). Which arrow is pointing to a pair ofkvml, x+ks+(giughq: , h:jg7 autosomes?

  Mendel observed that therftbpl:.50oy9zujs(s;ed- 4y , d-u+reaaplj e are two possible variations of flower colour in pea plants, purple and white. After a genetic cr;ot,lpa4.s l a-05d- ujyp ree+ 9:ubsjfzy(doss, 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 childrenaf 3td,xki-lm z78 h8vv yhn*; born in London in 1991h fd37z,i88t;vh- *lma xnvky.

  Which of these traits is an example of continuous /xi1ek:n irfk2j:guol 8 c/ cu*2g8tnvariation?

  Which row correctly describes diploid and haploi9)3o t1gwn9imu n sen4d cells in humans?

  The following table shows the diploid chromq2looa,nv+ +sbst. ;nt -co8mosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive a0ou5gm gdb r:25pfh .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 blood type O. What are k-pq+:gyzmyv2 q2 / lwthe possiq y+g/vp-yk2:q 2 mzwlble genotypes of the biological father?

  Which row shows the correct ant)tf)k 0dz3okg*fr3 vnotation of the alleles for blood groups?

  Which of these statements are trun v(daaw:,o :fe 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 spreadk9 z p/rdm11sqk: 4maa of malaria across the contine zqm1 /d1s:mk r4a9kapnt 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 (q2 bmx,4f/skgfw5w d/q ,)hediz92 urEquus przewalskii), 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 dominant to one to ffwz mdeg4s292r ,)dbqquwh/ k5ix,/ ne (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 linkem*o /i:zho 9eod and unlinked genes.

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

Sickle cell anaemia is caused by the allelofehb 5 mx+89 oq3ba6f)r,feg e 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 a male cat thah;5kxn kgd2y imo.+ 3et is homozygous for brown, long hair35 xy d.o2+eiknmk;h g and a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamdi966kvzttl xx(.2 dl ond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) is6 t(d txd klv9xi26z.l 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 short hair a4pkot( s/i y((l), and curly hair (C) is dominant to straight hair (c).ktisayp( o/(4 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 y cx5 vbw(,dgnv 08tlo2 2,bodinheritance of the condition shown in the pedigree chart belowdov2g(y2twc8o5bldx 0n,b, v?

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

  Which of these statements about genetic disorders is/are correct?: q-u1 t iw)k1off4lzt

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 shw7qw(nxd)5lh hux(+q r bj 6h 5bu(ot0ow 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 tkt6)cmkg*t/rs7vrtj vi:8pd+ k( ik 9g;d6gghe disorder shown in the pedigree chart is X-linked recesj6t/g+kg;vg(7gk*6r k k ci:d)m9vtr p t 8idssive and not autosomal recessive?

  Different species of living organisms have differed;(7 7ehh0hbtpbh ogqpuj5 w:4, wt z4nt numbers of genes characteristic to them. The table shows the estimated n:hdtwjgp 745tew;7b0 pohq z 4b( uhh,umber 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 char kqk,07n us02xfcgz7jacteristics of pea plants, including flower colour. If the pea plants Mendel was studying can only be white or purple and follow the rules of Mendelian genetics, which of these statusj07nk ,07 xzg 2cqfkements was correct?

  A biological male with hemophilia a- bn)2mv x2pon 9bjvd(nd a biological female without hemophilia have a daughtenbv(v 2) dm bjo9-2npxr without hemophilia. What are the possible genotypes of the daughter?

  A dihybrid cross was carried out between two sunflower plants (Heliao36++uxtkqz m nthus annuus) to see if the genes for seo6q t+mzx uk3+ed 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 type A and blood type yi1,nbtytdzo l a7ittpd:7 ;.p5; 1orB can have a child with blood tyobrdtopnp:a ti 7y1,;1zitltd; .57y pe O.

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

3.Explain the role of inheritance in genetic diseases.