A man and a woman have a daughter and a son. Their daughter has normal s qqbxsuh0v..x7ptj rw88., fvision, but their son is colourblind. Which one of these genotypes could be correct for the biological svbs.rt,x88p0.f 7 xwuqhj.qmother?

  Which diagram shows the sex chromosomes of a somatic cell in a human mnw;jz xz9.j8 rale?

  There are two alleles for floahf-13 plr+ gdrfb8ro.r+ -fkwer colour in snapdragons. However, the result of a cross between two heterozygous plants rl-o+f-3r hf d.1rfr+8kpabgyielded 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 demxid +.ma( ni/finition?

  Which of these statements ix8bnkkh/v . yv8v4d htw1.+n is a correct definition for a gene?

  The diagram shows a pair of homologous chromosomee;h0dws pj29l4 8iidvs.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were croo2- fb 0d5joitssed in an experiment. Which row shows the expected phenotypic ratiosoo t0jbd5i-2f of the offspring resulting from this cross?

  In some animals, the agouti allele causes individual hairs 9i4) 83egskc7hkrywq z;( ygpto have a banded pattern. The non-agouti allele causes hairs to be a y7( 4r c3 y;g8 e)hgqkwk9zpsisingle 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 individual pea pla0 /3bg7lpg:x f;b opednts was either round or wrinkled. The results of an experimental cross yielded 315 offspring with round seeds and 105 offspring with wrinkled seeds.d7x :3pe;bf gpb0go l/

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

  Neurons of the fruit fly (Drosophila melanogaster) havef73d vj:j knb 9y(x8ak 8 chromosomes. How many chromosomes are in a fertilised oocyte of a7k(38j xy kf9:vndba j fruit fly?

  When does the random orientation of homologous chromosome pairs occu2 v2qcr tm3e c4tap64kr?

The majority of the genes in the human genome k +zucw:wd 4s3k9yza2have already been mapped, meaning the exact lz syww:u2 +4kcka9d3 zocations of the 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 defo:waj b)x i1f3inition of linked genes?

  The diagram shows a karyogram of a brown male rat (Rattus n.a tdmifm+90oh rji13n( c(xjorvegicus). Which arrow is pointing a +hjrm9 fc.i1 tm((xi0djo3nto a pair of autosomes?

  Mendel observed that there are two possg/a lscz:m4qz + z1fs57qd.hkible variations of flower colour in pea plants, purple and white. Aftek f7zqzc z4:h5+1amgs./l dqsr 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 frequency1b0vh1fmc x- r of birth weight of children born in London in 1991.1-1 cfvhx0rb m

  Which of these traits is an example of continuous vvb1o2zzx 13yjdu-kjo+;xn(s , +iepvariation?

  Which row correctly describes diploid and haploid cells in hum(9j*)+ +ter z d(axh0ne ftrshans?

  The following table shows the diploid chromosome number or182vl7 h hfz5dd+rxf1z) dohf a range of species.

Which of these statements is correct?

  Sickle cell anaemia is c) cf5tbke s6+naused 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 chillhih yxv3 o8fp; 10pb8op) ;pmd with blood type O. What are the possible genotypes of the biological fax)1 pbhi p8y l;m8o;p0ophfv 3ther?

  Which row shows the correct annotationf-l.h zt2d 2 (lzroje)4n: vco.wplg 0 of the alleles for blood groups?

  Which of these statements wc,t7 03sjfqq6krxg i3u 4k t7are 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 malaria aba9hk:i ) hpi+cross :p )ahi h9k+ibthe 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), ftciu 8w1ge0g:ak/ 4irg 9g/ sbur 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:c0re gggu 9aiw8 t/gi/sb14kne (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 linke c, :sgq2yr1ar-hv;lzd and unlinked genes.

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

Sickle cell anaemia is caused by tu yh jz36efgi2hpw22fp)51nzhe 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 a male cat that is homozyg1vgu88f *r / jr aw(z(telhy,yous for brown, long hair and a female cat that has black, short rh,fy(ytgj e/v881 alr w(u*z hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allelee5wwa7n.x:hk(wpm u 6 for diamond-shaped seeds (D) is dominant over oval-sk:(6xmhawn ewu 5.7w phaped 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 3n *j12ydx+ iptvmic0dm 4rvpjjw-05 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 pigs and femalejyn1rvmx2v 00w4tjc+jpd dpi*5i3m- 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 inherita +yrnzkj n/z0.s+kgi5wqa 1 aaj;v b38nce of the condition shown in the pedigree chart below? +r 3z1jnq5bs+; .aiaygj8/ avw k0nkz

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

  Which of these statements abqjkb,yq4r6ona6.id*8wz1 e p out 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 polygenic trww+*qqb* x q2.8pbemsivt.f* aits 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 ongk/ js.t -y tmy93nr rincy,+59 :icof the disorder shown in the pedigree chart is X-linked recejc.r9 ms:5/tg i,-9 +ytnrnyk3onic yssive and not autosomal recessive?

  Different species of living organisms have different numbers of genes charactergwnjoihg , d4+kb4oi8u h(6j4 istic to them. The table shows the estimated number of genes for fij4 8kng(ihogdbu wo+, 4h 6i4jve 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, inclv kpner7() pg7;:lhge*a0n5glo up0suding flower colour. If the pea plants Mendel was studying can only be white or pup guh(e ver 07a:;n kgo7ls )lp0pn5*grple and follow the rules of Mendelian genetics, which of these statements was correct?

  A biological male with hemophilia and a biolog6 -j7daw7+af ncn;losth7o*t g1 t5al ical female without hemophilia have a daughter without hemophilia. What are the possible genotypes of the dagt n ldaohs7 *jnt7ota-+7fwc5;l 6 1aughter?

  A dihybrid cross was carried out between two sunflower plants (Hel gtp;wm7m6yx/ifzd ,;ianthus annuus) to see if the genes for seed number and seed sha/gwyi; p7, ftmm;x6zdpe 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 B can have a child w( xspf:n-s-vbp1czc * jf3zx,c2wj/2qfk +luith blood type(fzxuf / cq2:j1lj-pswb2cz ,*p-x+kscfvn 3 O.

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

3.Explain the role of inheritance in genetic diseases.