A man and a woman have a daughter and a son. Their daughter has nkhic 2hs7d-ny b3411iz 6wuhjormal vision, but their sy13hhd i-6 wc24bzns7 j 1ikuhon is colourblind. Which one of these genotypes could be correct for the biological mother?

  Which diagram shows thecj*y9dg ;8a, edp 4clp sex chromosomes of a somatic cell in a human male?

  There are two alleles for flower colour in snapdragons. However, thhzv-;mcsnh34 e result of a cross between two heterozygous plants yielded offspring with three differen43chnmv-hs; z t observed phenotypes, red, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to the g:s. a4jcvo+n7ef/zhv8yq(b correct definition?

  Which of these statements is a correl4 c 1gnkq w xkfrs*9z7m96 2wwfobc;1ct definition for a gene?

  The diagram shows a pair of homologous chromoso02le743qi g0nzx*( t dsi patnmes.

How many loci are shown?

  Two individuals, heterozyy/am qn :*xeh*gous for a specific trait, were crossed in an experiment. Whixe/ :* y*nqmhach row shows the expected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti allele causes individual hairs to h y4fh,tdc9ay*)s9 vgr0 rak .csd t4i-ave a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who are heterozygouc9*as0i,gcs yk9t )-44f .r rt hdyvdas 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 plaxgocg3/i zh;4 l17 ornnts was either round or wrinkled. The results of an experimental c o;olg7g1z/ 34ixhn crross 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 chromosome chrgz .+ev9t ,zagfxm p6.w+*s. How many chromoso6gwp fr++egcvzh* t 9,.x.ma zmes are in a fertilised oocyte of a fruit fly?

  When does the random orie. *tymf,;snc h1 rb 79fcc oywpjcd+*0ntation of homologous chromosome pairs occur?

The majority of the genes in the human genome 4 u6h f;wmt( )9)/mqbdoibcm nhave already been mapped, meaning the exau 6c;qdmo m(9))/mhtfb nw4ibct locations 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 definition of linked g4w4x4,h+zfpw7 (j -xn mllisuenes?

  The diagram shows a kag17 8 ,fwrqwz (wvx5leryogram of a brown male rat (Rattus norvegicus). Which arro wfq18vl(gzw 7w,rx5ew is pointing to a pair of autosomes?

  Mendel observed that there are two possibl + y ,4yi7 8qdvklgm ehoge,1emp0m);se variations of flower colour in pea plants, purple and white. After a genetic cross, the ratio oydse80vq,;,m 1)gk+ mgp eiyeo7lmh4 f plants with purple flowers to white flowers is 1:1. What were the genotypes of the parents?

  The graph shows the frequency omt)c vk2pe,5 alogr:s* u(lmh)b)/wxf birth weight of children born in London in 1991. kg/:(c5 l mswe) tbr2up,a)xolh)m*v

  Which of these traits is an examp:1e 56 f,hm-ugw umbrele of continuous variation?

  Which row correctly describes diploid and haploid cells in humansbeu3,k ;op kay)z3*wm ?

  The following table shows thu:s5.oze(t(p yo *u 30ji oblse diploid chromosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused7 dyi0zac c7pot 6a84h 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 child with blood type O. Whatx gm 8oy;*0)uv zce4ke are the possible genotypes of t0xv)8*e ueom;k zc4g yhe biological father?

  Which row shows the correnri a2x*z/)+qea4n +ohs57p keebo )tct annotation of the alleles for blood groups?

  Which of these statements are true for allelesxp5x 8k -;v net-h-:wucd+vh7ef wm2f?
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 ac2 re8g9h fah*fywho 12ross the continent*g f2eahwo8y9 frh2h 1 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 :+zu t+lnu.po :w lrc7(Equus przewalskii), fur colour is determined by a number ofnl+ uuozc.:+pt wrl: 7 genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) colour (P) is 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 l f)(l8rbds 6w)hgz)jlinked and unlinked genes.

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

Sickle cell anaemia is caused by thekk234 +mx9di xlimh9m 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 catqfy8 -wre8lkzy:x u;g)0/srp that is homozygous for brown, long hair andkfpl -wq8/)zy8s;xu rryg: 0 e a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamyy5iai8b -zb.ky 2rx5ond-shaped seeds (D) is dominant o b-yxz. 552b ykriai8yver 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)qnw 4hc 9ymc24 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 l4hw2nc qyc4m 9ong, 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 o8cnyh y7 zjd9;f the condition shown in the pedigree chart beloh cz dy;jn87y9w?

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

  Which of these statements about genetic disorders is/are cor1 pzlu6+nlut) r l)9ovrect?

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 distril2 4d*9zjlj/ km ucn9xbution.

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 char pfw:5jadhbdym t8y-9 .6gmj- zro3l2t is X-linked recessive and not autosomal recessgw-dt holb rym38yp:z-aj5.jd2m9f 6 ive?

  Different species of living organisqj623 af gp-yqbcy,o+ms have different numbers of genes characteristic to them. Thya, 6cbp3 q qjyf-+go2e table shows the estimated 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 pea plants, including flortoy5b7 .6w57 ghqmf9 d huc-xwer colour. If the pea plants Mendel was studying can only be white or purple and fol y76tq b9mcxf5hw7 dhgr 5uo-.low the rules of Mendelian genetics, which of these statements was correct?

  A biological male with hemophilia and a biological ( x ;., wvmbrwnswrxv8e75( xwfemale without hemophilia have a daughter without hemophilia r,v;swww5xme7(8vn.xx r (w b. What are the possible genotypes of the daughter?

  A dihybrid cross was carried out;d6 h1ei7 ys 6qgn n.tg2u3z1 stdxgu) between two sunflower plants (Helianthus annuus) to see if the genes for seed 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-squaqngu x;gsnye)dt it2.1s1h u3 76g dz6red test was 10.05; what does this indicate?

1.Explain how parents wi -qzkx 7kw,t*rzb:2jm th blood type A and blood type B can have a child with blood typejqxk2 zmz twr* bk:7,- O.

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

3.Explain the role of inheritance in genetic diseases.