A man and a woman have a daughter and a son. Their daughter has normalp/ha3l*twhdnz ) 10 ft vision, but their son is colourblind. Which one of these genotyp0 )w zh1t3p*/nfd athles could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic cell in a humar8)evx2q6 c lwn male?

  There are two alleles for flower colour in snapdragons. Houzpw+n;,h4njgl j4/utgh1); fr ka-i wever, the result of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red, white and pink flowers. Wz/n4athnl )-1f;gh g 4ur ,;jw+iuk pjhich is the most likely explanation for this observation?

  Which keyword is matched to the correct definiti v ztdqq(ujjtrnn*:,3tg* ) 8uon?

  Which of these statements is a correct definition for a g).0i 6krk7li x jjy)dnene?

  The diagram shows a pair of homologou(s2s q1d o7 yxdf+pc0ss chromosomes.

How many loci are shown?

  Two individuals, heterozygousz1w(k 7nih cv. for a specific trait, were crossed in an experiment. Which row sho1knh i.zcv 7(wws the expected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti allele causes individual hairs to have a banded jn*h3xjp+db br* l f)8pattern. The non-agouti allele causes hairs to be a single colour. Individuals 8nd px+)bjl*3jh frb*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 se v/k5l3 msylp*h u7gsyrk;-b o(/ggd: ed shape in individual pea plants was either round or wrinkled. The/ugb/yh: ym5l;s* - 3gp(kvk drg os7l results of an 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 (Drosophila melanogaster) have 8 chrom hhckd6s0/on*,n jp4 c+lklf:osomes. How many chromosomes are in a fertilised ocn6f*/,+ jn kl40kspo dhlhc:ocyte of a fruit fly?

  When does the random orientation of homxq+k(ccgyr3*17 o: 1ufij ksmologous chromosome pairs occur?

The majority of the genes in the human genome h2hsty7*cbi vb;sk*g 6ave already been mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one representation of a homologous pakcib76 v*g syt;2*h bsir 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 li9cg8t)maogj67h v sy .nked genes?

  The diagram shows a karyogram of a brown male r5 zwe8cz.r0.jge : hsnat (Rattus norvegicus). Which arrow is pointing to a pair of autow:.8ecgszn 5rzj he0 .somes?

  Mendel observed that there are two possj dcrr/bks0.s *g2yu8*- gh0 gyckip(ible variations of flower colour in pea plants, purple and white. After a genetic cross, the ratio of plants with purple flowers to white flowers is 1:1. What were the genotypes of the parents? c0 p.(r-*rcbihgjd8gsksuy g0k* /y2

  The graph shows the frequenv3xo,wn ifz26 9hbyg, - vabi,cy of birth weight of children born in London in 1991.iv,,ay2 9vigbownz,f -x6h3 b

  Which of these traits is an example dhc*4a3 ox4uwof continuous variation?

  Which row correctly describes diploid and haploid cells in hu6f mxsym (c-0+mq+phqmans?

  The following table shows the diploid chromosom;o,c) rx2bhrcqh2mj bs,(y- si96 rtle number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by aychgn269yw/340u q zt *sa*rw haemw2 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 typ :o 5fc u.pbpe;d()iuoe O. What are the possible genotypes ouip d)b.op5( ec:fu;of the biological father?

  Which row shows the correct annotation of the allelesh*v:ubwq u sg0 369lk b(vyoi0 for blood groups?

  Which of these statements are ,xj.xfod,hu*gakq4 ,t 3xu8ztrue 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 mal2,wuxrb) f;:76e jf fmt b0yzjaria across the continent ofme6xtb7)bj; 0w fzfrj: f2, uy 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 przewa6mn/uzzebu(x5yiq; u+6j2 yo lskii), fur colour is determined by a number of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two uu/ynuzxoz5j6 26+ by;iqm (etone) 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 and unlinked genes.;m2.be if8ec qr /z,j 8f9knba

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

Sickle cell anaemia is cause,cecdb sr8 l+ 7nph3w7d by 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 homozyn:4lo(d , kpqcgous for brown, long hair and a female cat that has b 4:o(,kqcnp dllack, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamond-shaped w pz2)q rarr1+seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) is dominant overqwrrr +)az2p1 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 p 0dmp /0; 8qnm cw0;+u6ttisfzx8 bexmorcellus), long 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 female short, straight-haired guinea pigs and a chi-squared test (χ2) ;8x0i6pm/ fe0xdw bu+z0mtc;snq8 m twas 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 of the cl.6/yyq2btt r ondition shown in the pedigree chart belowtt qr/ by2y.6l?

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

  Which of these statements about genetic disorders is/are correctw7rrjli5 f-/ k?

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 ;wx ( +n) y)5cvs wvzxjn/. ks4ik9hecnormal distribution.

2.Outline the differences and similarities between homologous chromosomes.

3.Explain why expected and observed Mendelian ratios may differ.

  What suggests that the ikv82+( hfy 6/nxvlp- tqx5nyhnheritance of the disorder shown in the pedigree chart is X-lin+vy6 x vtqnpf2 (y-8nlkhx5 /hked recessive and not autosomal recessive?

  Different species of living organisms have differl 7w s-2*plnjlw ebw 7a,ugu4p9hot/8p6w+ bwent numbers of genes characteristic to them. The table shows the estimated number of genes fortw *o pwb- b/9n72a+ hjww w suell84u,7pplg6 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 characte(k 9*n5q4zn alrohz y-x59undristics of pea plants, including flower colour. If the pea plants Mendel was studying can only be white or purple and follow thz9-5y 5 nou9k (dn*aqzrn4x lhe rules of Mendelian genetics, which of these statements was correct?

  A biological male with hemophilia and a biological female without hemo7-p io k 7j yg5wbkki-m(i2si9philia have a daughter without hemophi92kkkgi-i7m pi5 -s j(o7iybwlia. What are the possible genotypes of the daughter?

  A dihybrid cross was carried out between two sunflower plants (Helianthus an4 *lt1j+c. zkb fikigt- 9wyl0nuus) to see if +9k y-*wibz.4l tci tljf k10gthe 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 88emfm 28il av f,b.0xqi eu7pA and blood type B can have a child with blood type O. 0 lf2 i7, ma8.ievqemp88xbu f

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

3.Explain the role of inheritance in genetic diseases.