A man and a woman hav3 ;tnxg, ;i: xiaemtqo7h -u:le a daughter and a son. Their daughter has normal vision, b3i,n t:a th-:mogx;iquel7;x ut their son is colourblind. Which one of these genotypes could be correct for the biological mother?

  Which diagram shows the se*b +b vj*4vuy9jmo;du. rjp) wx chromosomes of a somatic cell in a human male?

  There are two alleles for flower coloua r nsp2sl3,-tr in snapdragons. However, the result of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red, whia3p-lnr,s 2st te and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to the corqy16ryyxnqoq5 fb a :64,iaa*rect definition?

  Which of these statements is a correct definition for a pgc2okm, o/se sut:fo;mj)opc54 ;) igene?

  The diagram shows a pairm1+smox( .k97ni eg7rq ;mpvt of homologous chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were crossed in an exper8d2h- m;emgodr- ) ,hk6pizfpiment. Which row shows the expecopz-eghi drhd- 8mm,; 6)k pf2ted phenotypic ratios of the offspring resulting from this cross?

  In some animals, the xo)+lmjk : /*j vsqd,cagouti allele causes individual hairs to have a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who are heterozygous have hairvjl d sx+ mcq*j):,/oks 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 ys*o.2f9ru4t fe qgm63zh y*wpea plants was either round or wrinkled. The results of an experimental cross yielded 315 offspring with round seh 24fe s rmy3*qz.u *y6fotg9weds 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. f3ohcnp2.k99w)7-pk w7eq rgsd1xnn How many chpkw-.9 p1 xd9r )c72neqwgkonnfh73sromosomes are in a fertilised oocyte of a fruit fly?

  When does the random orientation of homologousqdur- 8 ;vmzw6 chromosome pairs occur?

The majority of the gez 7l.06byqzs9 n7ih awnes in the human genome have already been mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one representation of a homologous pair of chromosomes z6qya0h l7bnw7.9szi.

1.Define locus.

2.Identify the number of loci shown in the diagram.

3.Distinguish between gene, allele, and locus.

  Which is the correct qaw-v.szk; 5fdefinition of linked genes?

  The diagram shows a karyogram of a brown male rat (Rr-8,gok8 vhii,ss7ckh i8ix )gi3tu *attus norvegicus). Which arrow is pointing to a pair of autos gi8-38 7ui8,grktoi*v cs ,siihx) hkomes?

  Mendel observed that there are/3 ghk+p8zpzg two possible variations of flower colour in pea plants, purple and white. After a genetic cross, the ratihzgpk 3pzg+/8 o 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 London in 199.9v)yqczyuemlkwgn3)pz- 5 dr(i9 )l1. .)yc9l) n93imv d pgyzw5q( r-uz)ke l

  Which of these traits is an example of continu50y *e mu9goho3bca5d o(z6v gous variation?

  Which row correctly des) umhhltajla1/j 4 ifqr- /(nmj0 0m;v:eg8dkcribes diploid and haploid cells in humans?

  The following table shows the diploid chromosome number of a ran13 gkrxsgw z xa ,c:tur73.7qmge of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a reh5cs7)hu -hco xu( o-tcessive 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 5)caj/kfv. la /;xj u)hia ;qtchild with blood type O. What are the ;/ )ajhajci;tflua. v /)q5kxpossible genotypes of the biological father?

  Which row shows the correct annotation f.tpmi/b zs/gq dk7,) of the alleles for blood groups?

  Which of these statemf3mq o 7q70oya:rgo+ polucurs/p- )i3gfp(:ents are 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 inntlrru( u119b5u 77vicf iu, ecidence of sickle cell anaemia and the spread of malaria across the conlb1ifnc ur(9uti5 7 ,u71 eruvtinent 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), fur colour is determined b uf8 3i5bbv hl3i(ct5-r 3tuxly a number of genes. Brown colour (B) is dominant to srt u3l538 fb35vi(ih ulxt-bcandy 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 linked- skz /wtjfmb2)/s8i2ufo 9 fe and unlinked genes.

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

Sickle cell anaemia is caused by b/la/2h;:u3eabpjah the 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 homozygous fo gyg93dk np*ej/00 tac3e-qy dr brown, longy9-/tea 3g3k*pygc0qj n0dd e hair and a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officm4n*susi xz:xuls*) * inale), the allele for diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (Lsn*4z**xius lux: )sm ) 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 0) z mumqf/1yrto 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 fem/1uz q m)r0fymale 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 q)f2;at ah ve*og-c2o inheritance of the condition shown in the pedigree chart be)h-af2e o *;2qo avctglow?

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

  Which of these statements about genetic disorders246 t ay pbmx:nm,2one 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- 1g(2etr uw e v*xn7kjsu;oh, traits 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 pedigree chart93 uwp+4 :0rgg0udjncm- svv;m hh :wd 4st)jl is X-linked recessive and not autosomal rv+ 0pch3d g:vt4 nwwdsmj; hus)m09l-: gu4jrecessive?

  Different species of living organisms have ditaj qja2 c c)1 c17yott6,sqp.fferent numbers of genes characteristic to them. The table act)a6t2y ,c t jo .j1qsq1cp7shows 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 pemt, 3kp52kfylr 9 aryfo;*ix(a plants, including flower colour. If the pea plants Mendel was studying can only be white or purple and follow th 9a r*tik(,3rk; o2yf fx5pmlye rules of Mendelian genetics, which of these statements was correct?

  A biological male withoy19fkr.lp 6n02qc xe hemophilia and a biological female without hemophilia have a daughter without hemophilia. What are the possible genotypel.yf pkoer9q1x6n0c 2s of the daughter?

  A dihybrid cross was carried out between two sunflower plantg- u0vznvh 2gr+a-7w9on 6d7nga5 jm us (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 o mrzvnvu+6h -ug02ggan-ndja 7w759 chi-squared test was 10.05; what does this indicate?

1.Explain how parents with 4ihc5ei-eivot2q; e7blood type A and blood type B can have a child with blood type ie5oit h ;v7 ce4e-i2qO.

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

3.Explain the role of inheritance in genetic diseases.