A man and a woman have a daughter and a son. Their 1c,r( jlww(exqnd940 mndu9o daughter has normal vision, but their son is colourblind. Which one of these genotypes could be correct for the biological m9j9en0mncuw( wx d(dql o4,1 rother?

  Which diagram shows the sex chromosomes of a soma l7 i/,hewcfd4tic cell in a human male?

  There are two alleles for flower colour in snapdrtamqm a*.9ce: agons. However, the result of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red, m t m*q9cea:a.white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matche ruk d8krr7jg:3r d87ge 4bw4nd to the correct definition?

  Which of these statements iq7qmy vw7rc154+zu das a correct definition for a gene?

  The diagram shows a pair of homologous chyb d2 egt+asd80(1vd cromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were crossed in d -mafwmx,e9+ an experiment. Which row shows the expected phenotypic ratio -,xwe fmm+da9s of the offspring resulting from this cross?

  In some animals, the agouti a es7is,;vsolj l73f+lllele causes individual hairs to have a banded pattern. The non-agouti allele cause,7sl fl ls+oi;7j s3ves hairs 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 ipxy:(/.l qzhe3so )f shape in individual pea plants was either round or wrinkled. The results of aq / ()3piy:eo.lhf szxn 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 (Drosoph5wie 9ifvwlm,b0(qt ;*)b kfeila melanogaster) have 8 chromosomes. How many chromosomes are in a fertilised oocyte ombbt9k v i0e,w(l)fwfqi5e *;f a fruit fly?

  When does the random orientat+ (pex9qma+umv9uqc4 ion of homologous chromosome pairs occur?

The majority of the genes in the human genome have alrasccm:r vs :,/eady been mapped, meaning the exact locations of the genes on chromosomes are knr, /ss cvm:ca:own. 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 gsz5yzq(h a(u8 dwp77henes?

  The diagram shows a karyogram of a brown male..hk zw4tnb(d(*eekv rat (Rattus norvegicus). Which arrow isb eed.k(vz .tkw(4*nh pointing to a pair of autosomes?

  Mendel observed that there are two possible variations of flower coloahu/c( w 3pi )kw6p+u5tjmew -ur in pea plants, purple and white. After a genetic cross, ip kwe)/ptu63wj w-(a5uhcm+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 children born in Londondj-goh db (q0 c150ker in 1991hj( cqg e-0d1 bko0r5d.

  Which of these traits is an example of continuous var wwejj iw;3, 1hd03bgjiation?

  Which row correctly describes diploid and c4:yrx (1 rqh(ri ,si3 luv5zxhaploid cells in humans?

  The following table shows the diploid chromosome number of a range ofc xvbk(v;7(cd rc *to; species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive allele (*kwn gfw*rs3. 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. Whatqh tmxa *)pc4:pq7/y, .jsgof are the possible genotypes of the biological father?jqf. oqxpcg a y*/ m4ts)7:h,p

  Which row shows the 65jp *oe4 mv :jk9ffbtz 7k0xtcorrect annotation of the alleles for blood groups?

  Which of these statements are trh.u5 o u0ly8diue 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 malagdesk:.kuw /rr7tuwi;+h e .:ria across the con.u. u: 7srkwdkgeetw /r:h+i;tinent 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), fuoasm1v 67;l lt cm0jgwl /)sp2r 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 ton7g6vcp)oss0j mltm awl1/l 2; e (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 unlikvt +*6. qvi+zpu gni/nked genes.

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

Sickle cell anaemia is caused by the allel esg9n4l:4gf nmlq0.2jr7x ape 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 croli:m,ya6tsj+ky: bdv ,cc+0y ss between a male cat that is homozygous for brown, long hair and a female cat that has black, cc:yaj l ,kyyds+0t,:i6v bm+short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diam w5ppdb ; lkwlrrf/p8;a21e1rc1 s6czond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the wps a8b1rp zl2/crk;f rd1w ;ce6l15pallele 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(etv32 tapv;liu6u4h 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 female short, straight-haired guinea pigs and a chi-squared test (χ h3;ui64 u( etvpalvt22) 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 inheri, l 8x aejka58v2(nmhmtance of the condition shown in the pedigree chart belol xhavnme 85m8kj,a 2(w?

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

  Which of these statements abog)kji m j6:f:-lcp/+wam9yvi ut 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 traic,aqwldnzj ltt//+ l9,.xu :wts 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 of the disorder shown in the pedigrexm ilt2; gj.: wnam)2te chart isn :ax jtimt m2gw.2;l) X-linked recessive and not autosomal recessive?

  Different species of living organisms have different numbers of geneekz5h c,gu t(a4ci5c-s characteristic to them. The table shows the estimated numbez hk5i cuc(c5,ate4-gr 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 pea plants, includin q irq79fqx;(q kf1/txu m:r*zg flower colour. If the pea plants Mendel was studying can only b :xzq9tr7q ;uq* /1fikfmqx r(e 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 without hemophilia ha ye.f es1lit s9ynr4s q.73xuq;dl3 d,ve a daughter without hemophilia. What are the pos.;y,sn3s9sq 3eutq.led174dly rxf i sible genotypes of the daughter?

  A dihybrid cross was carried out between two sunflower plants (Helianthus annuw)v/d3)qmt:3d pvo y dus) to see if the genes for seed number and seed shape are linked. The critical valqy d) tv/pdo3dw vm:3)ue 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 bloodh9tib ew8t;k30guf: p*vqi2i type A and blood type B can have a child with blood tig 39t i*p0fe8wkv ui2 h:t;qbype O.

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

3.Explain the role of inheritance in genetic diseases.