A man and a woman have a daughter and a sormm:07:v s dqr)czdz/ n. Their daughter has normal vision, but their son is colourblind. Which 0cqd m:rzzvs d)m:r7 /one of these genotypes could be correct for the biological mother?

  Which diagram shows the sex chromosome(rw1 fsf76w /duntj+ ss of a somatic cell in a human male?

  There are two alleles for flower colour in snapdragons. Hok p +9v-nba9e )k8f(2v,sqqw+qdu wqz wever, the result of a cross between two heterozygous plants yielded offspring wan) b kqvvq2fpw9 w-(9+,ue 8qdzqks +ith three different observed phenotypes, red, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to the correct definitidd6fg 5e(hwf-iyxy 13jg k87hon?

  Which of these statementsz(o) ysv)kxs4 u4y5un/ u4wfv is a correct definition for a gene?

  The diagram shows a pairz4 4do ,omnlu9qk 2un+ of homologous chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were crossed i9 lls;9erfyh z ra+o .:-i,qtmn an experiment. Which row shows the esrlh9arf., 9qlz m;ei y:- to+xpected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agou0ykmkc9ei35bx 5,(di n8 ncp2;cswjbt- ij i. ti allele causes individual hairs to have a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who are heterozn,;i d5y 0tc5nekckjji-cb. xs(bwm 2 9ii8p3ygous 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 plants was either round nu6 +:tqz z3snga2zz7 or wrinkled. The results of an experimental cross yielded 315 offspring with round seeds andzut3qg :2zaz6sznn7 + 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.* leu hw;gzs;e/tj*(z How many chromosomes at ;*jz(;*g eswzl/ euhre in a fertilised oocyte of a fruit fly?

  When does the random orientation of homologous chr 2cs5sqxdzp +4omosome pairs occur?

The majority of the genes in the human genome have q +t q1rvbal bhsyi(a 6l(el9pt;.m*hc-kh7, already been mapped, meaning the exact locations of the genes on chromosomes bal i p(l y;hc+b th 16l,tr*qma97hesq. -v(kare 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 dwj(ednp,a; m2el*e 2 vefinition of linked genes?

  The diagram shows a karyogram of a brown *9nf5 qg8j5:x x.b b8dbsgqzamale rat (Rattus norvegicus). Which arrow is pointing to a pa q8 db5gg: 5.zafsjx9qxb8n*bir of autosomes?

  Mendel observed that there are two possible variations of fl8l6q3ky ato+*4r++c.h zdf1c gmt qzdower colour in pea plants, purple and white. After a genetic cross, the ratio of plants with pu3y *6a+dqz 8mdk4hof+q z crt.1tcl+g rple flowers to white flowers is 1:1. What were the genotypes of the parents?

  The graph shows the fe;ijo/nwql ef7ji.8 m(g, b+7dps m5grequency of birth weight of children born in London in 1991;s(q/ gi+ljbei d 5m7j7ef8p ,wg.mon.

  Which of these traits is an example of continuous vard4co9ax(ez,ny0o ep9y,k zy0iation?

  Which row correctly describes diploid and haploid cellsq.+ht v33cgmu in humans?

  The following table s (yv n(f.uz3dchows the diploid chromosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a rec/dsl)ai6yq t 39d9eo qessive 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. What f.r: a;k 9-: jz sc5lbrf2.gzg0 dpnlnare the possible genotypes of the biological fathec0 n:z-d r pj l.f2ng5g;:balr 9f.skzr?

  Which row shows the correct annotation of the alleles a jy-1r( s:cjwfor blood groups?

  Which of these statements are tru e4czo)r ud9u9;:ki,:w;ia) ztdl ngue 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 cellaedl1bwespbs ;:47sz t18 ix3 anaemia and the spread of malaria across the continent ob:dei plzsw13 a x s;74se1tb8f 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 pyv9oasa4yg8rbd8 p+- rzewalskii), fur 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 y8 ra8 db9-+y agsvp4otone (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 lig8/ i)n inp)yinked and unlinked genes.

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

Sickle cell anaemia is caused by the alsav.* adw jfs:g h)ib2c6 dj(t2icpz-o3g4 * hlele 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 malz w/5bl cf;7frop5 ,xie cat that is homozygous for brown, long hair and a female cat that has blaffr/bz cwx7 , oi55lp;ck, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamond-shaped zz:mtld1ng ;.seeds (D) is dominant over oval-shaped seeds (d) and the allele for long sgn.dlm z;t 1z:eeds (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 to short hair (l)w)r;j8 acb4 rs, 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-squarecjr8sr 4w;b )ad 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 of the condition shown in f 7tyn5k8 z5sb9y(oucthe pedigree chart below? tyu9so5 b8n7fc5( kyz

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

  Which of these statements about genetic disorders is/are co).c iqjh/ u7ookqw/h4 rrect?

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 distribd+n w8 :,hd ues0)wfcxution.

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 pedigr.kelabuf7;a gt 3d8r5jg e,(see chart is X-linked recessive andt 8,r gj 7ae(3l5edkugab.f; s not autosomal recessive?

  Different species of living organisms have different numbers of genes characteri(/k7wfhl m t qbe6, i)+mlp2iostic to them. The table shows the estimated number of genes for five spec)bqlip7ekf(ilm,/6oh t 2w m+ies.
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 plan v:u(m)8iuve:ip s d:kts, including flower colour. If the pea plants Mendel was studying can only be white or purple and follow the rules of Mendelian genetics, which of thesmpi8(du::k )evs: iuv e statements was correct?

  A biological male with hemophilia and e0,8lh+vn v 2hbufo03ml/ ogva biological female without hemophilia have a daughter without hemophilia. What are the possible genotypes of the daughb ufl0eh o8vvh20vmo lg3,/+nter?

  A dihybrid cross was carried out between two sujlwols;4fb 5f 2rq (n(1so.zvnflower 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.olqs 2o; lz.jnrw4bfs(fv 1(582. The calculated value for the chi-squared test was 10.05; what does this indicate?

1.Explain how parents with blood type A and blood jon 4:i br9tc*m6xu a.type B can have a child with bloodt4*: ab6.r9xcjomi un type O.

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

3.Explain the role of inheritance in genetic diseases.