A man and a woman have a daughter and a son. Their daughter has normal vision, bgtp) qm6/b 6 3g3kiwc/)ffuv out their son is colourblind. Which one of these genotypes could be cortcp / u6wb6mf33/ gf kgiv)q)orect for the biological mother?

  Which diagram shows the seu)l*5* vnvi lyx chromosomes of a somatic cell in a human male?

  There are two alleles for flower colour in snapdragons. However, the rp3v (vr9 8avthesult of a cross between two heterozygous plants yielded offspring with three different observed phev (pa8hv3r v9tnotypes, red, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to the correct -7hxzv-bzu md ep- -k/definition?

  Which of these statements is a correct definition for a genfu2u lt 2nb*v1e?

  The diagram shows a pair of homologous chrm khxwj*e fl3v4y/ur)7r7t g,omosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trp+mo*-xh (2zwuo 2uv2 afy5 fn.qxvl6ait, were crossed in an experiment. Which row shows the expected phenotypic ratios of the offsprinf x2a2uhovxlfnmo 2. +wqp-5*v6(zuyg resulting from this cross?

  In some animals, the agouti allele cause4kda 9bt x9d8gag z4/h 4fp)k.n p8nnbs individual hairs to have a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuals whap4 8bf)n g4 hzt.9ad 4/bpknn9x8dkgo 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 .xgaqwfwl;d7 tg o+ ,*the seed shape in individual pea plants was either round or wrinkled. The results of an experimentalw*o7 +d.,gl;xt qgawf 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 chromosonfoy1adp el v;1w239h as 79bomes. How many chromosomes are in a fertilised oocyte of a fruit f9;a12p1ay o7 hn9b 3sldowefvly?

  When does the random orientation of homologous chromosome paiy/.6x*wqs 4+)ybcbm7 z rcwscrs occur?

The majority of the genes in the human genome have already be0qpvo/ 3jy2 bben mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one representation of a homologov3 byboqj0p2/us 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 definitio bp a *un4agcog-g*)s0n of linked genes?

  The diagram shows a karyogram of a brown male rat (Rattus norvegicus). Wh(vnqu: 9m 4t)s p2vfw1) fcxvoich arrow is pointing to a pair of autosw(o:m19)qvu4vn f)cp s txf v2omes?

  Mendel observed that there are two possible vartgyzmj zykp) c-;b9d, pisgs3w50e(, iations of flower colour in pea plants, purple and whit)z-g,i3sy0 t;gk w5deyp9bzs pjc(, me. After a genetic cross, the ratio of plants with purple flowers to white flowers is 1:1. What were the genotypes of the parents?

  The graph shows the fre3na5q7 ,qy q,68ewhaftq1zyequency of birth weight of children born in London in 1991e3q1,f 5zh 86qaeqqawyy,7tn .

  Which of these traits is an exampl0kcd k6c 5 n(. cypaaw8:k(bzq4ori3e e of continuous variation?

  Which row correctly describes diplcbhtd(a alx9ifc4, 2m7a*0tp oid and haploid cells in humans?

  The following table shows the diploid chromosome numberb f-ze2/q p ,2koot9kh of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive allele (Hb rfw .n4qh/r0g$^S$). 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 qgz10c ns9;gz(w1iabkne 2f . with blood type O. What are the possible genotypes of thn(q1snzz0 fi9.eawg1b k;c 2ge biological father?

  Which row shows the correct annotation of the alleles for bl5 8;4j4qgk-tc l gc3qm3jn,zlyvu di-ood groups?

  Which of these statements ar1b(9bp fg5ke 5(n zueie 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 incidence of sickle cell r;c+ n )l 4id8ijowf/ranaemia and the spread of malaria across thrri ;)4 j+8n/wfdlco ie continent 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 by a n ltrcv .qoa0zu:;; (,jmx1xt )sarm9number of genes. Brown colour (B) is dominant to sandy colour (b) and an z,nxmv a 1;s :0a(9o.mjttrrxc u;l)qombre (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 and unlinked gep vqu4;v.rp ws8+cwv6nes.

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

Sickle cell anaemia is caused a*)hn* hcu- rq9c2slfmqzetj7+2bo 2 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 v4m:z:q rd ng3-fg2 ngcross between a male cat that is homozygous for brown, long ngf34 :m ngg dv:zrq2-hair and a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinal sy1g8x, n+ikie), the allele for diamond-shaped seeds (D) is k,g xyin1i 8+sdominant over 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) is dominant to short hair (l), j v5 ll ooi- i+uwi;v8rvl-k14and curly hair (C) is dominant to straight hair (c). A test cross was carried out bevl48+o o1v -ijl5kr ;lu-viwitween male heterozygous long, 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 o r1:y3jj7 v1 p m adx:kwc0/ig7y 5vjk9x-xhbqf the condition shown in the pedigree chart bx1j93 gabj k xyj mp/ xcy7dh0:5ir7q-vwv k:1elow?

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

  Which of these statements about genetic disy59*x,;+nn p*(sxekrer5 vf+ l(cac4wv gok xorders 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 traiar5fbv4j+9 , 8gxmod its 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 disi fk79ks5x-xzq- lz(a order shown in the pedigree chart is X-linked recessive and nf7axz5-(kksix z9lq- ot autosomal recessive?

  Different species of living organism8,87/ u etixou,ju7tg er )uz 1i nbs)aqm:5ais have different numbers of genes characteristic to them. The table shows the )1/i )ui riab8ox:g atzqjus75 um7n,eu,t8 e 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 flower colour. Iff7ab um;- jxfgt3*5eaj pz+) h the pea plants Mendel was studying can only be white or purplguff* e j;jmta)z 3p-57+hbx ae and follow the rules of Mendelian genetics, which of these statements was correct?

  A biological male with hemophilia and a biological feot hqtvw m8sz0;12lm3 male without hemophilia have a daughter without hemophilhl 8;ms mqv1z0ot32 wtia. What are the possible genotypes of the daughter?

  A dihybrid cross was carried out between two sunflower plants (Helianthml8qf6v gtvh7i)pt r r*)q.7i us 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-squarr 8 h.tg* vvmltq)i7fip)q7r6ed test was 10.05; what does this indicate?

1.Explain how parents with blood type A and blood type B can have ; 12diydr - flxzf)l0ga child with blodfr01i f;dl2 zgl-x)yod type O.

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

3.Explain the role of inheritance in genetic diseases.