A man and a woman have a daughter dw ;-49*n ymstqruip0and a son. Their daughter has normal vision, but their son iswur*pq409d m-;nt syi colourblind. Which one of these genotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic cell in a human male 87fmftmwnxb1ccpf8v cq.z7:-;:j hx?

  There are two alleles for flower colour in snapdragons. However,ef9bdmmv 0b )1 the result of a cross between two heterozygous plants yielded offspring with three differentmv09de bm1f b) observed phenotypes, red, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched t wh5+4:gwwr rpo the correct definition?

  Which of these statements is a:b l bcmp1,lf0tcg 3ri*+ s.mp correct definition for a gene?

  The diagram shows a pair of homologous ctg(yw)gd 2z*g y, niwxc6ya; -/*kedh hromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specifn5:;.poscw*nfns 4 i s 05bfnsah8 tttw t,4g)ic trait, were crossed in an experiment. Which row showsn tw: sa8s 4,ow)f0hns4.;gf i5 *ctnnbspt t5 the expected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti allele causes individual hairs tor./+y0/*jkhw layft d bg8u/t have a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuadrfy 8*y.uwjtgb / 0h//+l tkals 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 shapelie 3 x29x l :no4 xh8b55ca;altq-bva in individual pea plants was either round or wrinkled. The results of an experibta e5a8lo 3qlxb: i4v;x2-axln5c 9hmental 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 (Drosku:g()de-jf bophila melanogaster) have 8 chromosomes. How many chromosomes are in a(k u)dbgj:f- e fertilised oocyte of a fruit fly?

  When does the random orientation of homologoc r1vxmhk,6o-us chromosome pairs occur?

The majority of the genes in the hs-rga8:jk81- prd4qkg+okmq uman genome have already been mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one representation of a homo d 1pjsg:akrqk-8 o4-mr+q8gk logous 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 lhn shb84 )xxhfj;ek;2xrlo;-u,3 r cy inked genes?

  The diagram shows a karyogra82j ipot,ff+ hrm 7 m0qtn7.fjm of a brown male rat (Rattus norvegicus). Which arrow is pointing to a pair of autq7j r+mf njft2t0p,m 87fhoi.osomes?

  Mendel observed that there are two possible variations of fhen +hytp0ci,4m,m 8clower colour in pea plants, purple and white. After a genetic cross, the ratio of plants with purple flowers to white flowerm, e n,0iphhctc4m+y 8s is 1:1. What were the genotypes of the parents?

  The graph shows the frequ(jo:3kq)omh h mq+,rmency of birth weight of children born in London in 1991.qo:m qmj+(3 hmhokr),

  Which of these traits is an example of continuous variation?ghy v3sdmam1ln-nw; e,2./gp

  Which row correctly describes diploid alzpyz8gqg)5 kcsbmpae14;3p xz-(m , nd haploid cells in humans?

  The following table shows the diploid chromosome numbfttheoqgwv( ,p 5xl44cn j/.6 er of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive7niehx:m1+ p p/w*q-mu32 zwj 0jd jsg 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 typ 3we s62afsr8je O. What are the possible genotypes of the biological father? rssf83 2 aewj6

  Which row shows the c*-vgv xldk*vzu1j;bb // mxzo4uao3 0orrect annotation of the alleles for blood groups?

  Which of these statements are true 6i 0bbd i0.yovfor 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 inciden*5 )vl bovt0vu 7ea de;2z/acmce of sickle cell anaemia and the spread of malaria across the continent of Afr 75avlo0/db2;aucm tv ev*)e zica.


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 by a numbejg //ovw4vbkg3kpk e*0c+k2 o r of genes. Brown colour (B)3kkv4 pb2ojgkwe*/+c o vk0g/ 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 6wv oxqkk 5y:3l 03exmlinked and unlinked genes.

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

Sickle cell anaemia is caused by the allele Hb -+12ftk5o xd a+o63psbolpae$^S$ . 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 th9x uwvlng j-ty63i j28at is homozygous for brown, long hair aw3ygu - j2 i9xnjtv86lnd a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamond-shaped seeds (De alnhl,(n/1d) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) is a/l1le, n d(hndominant 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 dominandwrj : *-qp+1njeo*7oqim:put 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 (χ2) was carried out on thwnoj1-*7o *rm:pdp+iu:qj e qe 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 thekjd;.91njd 9 en+6 5sdujt.s;m w ivdi inheritance of the condition shown in the pedigree chart belo+ dmjd9i9v;1us ke.5 6 s;ddi.wjtnjn w?

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

  Which of these statements abo hu8mmd/db1b 8ut 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 traits cao31gdihu: sj(ty k1h+n 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)vdtl 2veg75f chart is X-linked recessivge 7t)5d vfvl2e and not autosomal recessive?

  Different species of living o +.,,ahy2g rof u9sa+q) enmwirganisms have different numbers of genes characteristic to them. The table shows the estimated number of fa + awqrgno 9ue )is+m.h2,,ygenes 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 plant0q5vlh*vb m5tv51v zds, including flower colour. If the pea plants Mendel was studying can only be white or purple and follow *05vbq5zvvmlv 1 5td hthe rules of Mendelian genetics, which of these statements was correct?

  A biological male with hemophilia and a biological female withos+ku40w5tbcct p s7 v3ut hemophilia have a daughter without hemophilia. What are the possible genoc t0kbs574ctpuvs+w3 types of the daughter?

  A dihybrid cross was carried out bxg f,8-:sva8 gcxyeedc o(-mjvu0q79 etween two sunflower plants (Helianthus annuus) to see if th- 9g 0: q8cfxsvavmcd,yeju(7o-e8x ge 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-squared test was 10.05; what does this indicate?

1.Explain how parents with blood type A and bl8pe gastn 6 gbj j/xfrb/yf+2*p;:9 qit2qyp 3ood type B can have a child with blood ty93ep/8r2n; j/ ajbgb6tyg q t+xypf*: s2 ifpqpe O.

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

3.Explain the role of inheritance in genetic diseases.