A man and a woman have a daughter and a son. Th t;ve )do(oyj*eir daughter has normal vision, but their son is colourblind. Which one of these genotypes coulj)t;oy*d eo v(d be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic cell in a human ma01z7tr fna(/ owa y:ynyk pf:;le?

  There are two alleles for flower covb , ;cc ox7lgz,fv18plour in snapdragons. However, the result of a cross between two he;87vo,cxf bc lvpz g,1terozygous plants yielded offspring with three different observed phenotypes, red, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to the cm9fbm4 21xoo.d7*fiyhfv c4 f lf v:7oorrect definition?

  Which of these statements isbl1f11)w)f lr b56qkye7 dvfb a correct definition for a gene?

  The diagram shows a pair of homologous chronae ow4 z1m41msy. wq7mosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, 5lc o 6 ax.6imigh*.bqwere crossed in an experiment. Which row shows the expected phenotypic ratios of the offspring resu.c6mxbi li56qg hoa.*lting from this cross?

  In some animals, the agouti allele causes individual hairs to have a ) l)ye(ugcc(bbanded pattern. The non-agouti allele causes hairs to be a single col)y)blug(e (ccour. Individuals 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 shape in indiva fpveqe r );x(e/l/4didual pea plants was either round or wrinkled. The results of an experimental cross yielded 315 offspring with round seeds and 105 offspring wi) exp /f(;eqrvdla4e/th wrinkled seeds.

Which row in the table below states the most likely genotypes of the parents?

  Neurons of the fruit fly (Drosopd89ed+uvw 4 )8aronkizkmytu17dk : -hila melanogaster) have 8 chromosomes. How many chromosomes are in a fertilised ooc e88z mvuk it-7+4r1oak wuk9d)nddy:yte of a fruit fly?

  When does the random orienh 3tp,x 35.cz: o0qutqau) kkbtation of homologous chromosome pairs occur?

The majority of the genes in the human genome have already bee rvkdi4zcqrd/4., zfdg3or 0350zr. ,vlgny n n mapped, meaning the exact locations of gyr fo.zn, z iz30r qgd v5l/4,cn.3vrd4rk0dthe genes on chromosomes are 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 defini z4lky7pqope-,648esgh fyfj0k-ht; l w. ma1 tion of linked genes?

  The diagram shows a kary*ilhj )hdx5a 9ogram of a brown male rat (Rattus norvegicus). Which arrow is poi d9iah*xhj )l5nting to a pair of autosomes?

  Mendel observed that there are two possible variations of flower colour in pea wd51n u(y7h utplants, purple and white. After a genetic cross, the ratio of plants with purple flowers to white flowers is n(u1u5ht7wd y1:1. What were the genotypes of the parents?

  The graph shows the frequency of birth weight of children born in London in 1991;zd b.q)6kxyo. yo b.);x6qzdk

  Which of these traits is an emeww-vzj))2 iiwpk2 /xample of continuous variation?

  Which row correctly describes diploid and haploid cells in humans? ;rb19 s0jtg9 8ui d:popo nz.t

  The following table shows the diploid chromosome number of a rvz24 1vfu9( ;k69finc7dvi g twsf dn1ange of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a reiu mz-/ ryrzr p8n84k/cessive 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 (a+j 9vqh6 z*ld-uj l:p eky*jhad a child with blood type O. What are the possible genotype av(: kule6d+y9zlqhp j**j j-s of the biological father?

  Which row shows the correct p:5 kbkus ex92) um.s6/je fvbannotation of the alleles for blood groups?

  Which of these statements arep b. on ved;0/w)iakv9 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 anaemia and the spread oivfagvoltbea )9 7 v8f--3 -idf malaria acrossfa gv7 a9-b-3i)tel8- df oivv the 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 j3s:lme i( ud3determined by a number of genes. Brown colour (esdu3jl:im(3 B) 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 linked and unlinkeg 1nxih+a k q 0o04 a0jeq5-t-psqt6gxd genes.

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

Sickle cell anaemia is caused by the allele Hbv:d vqly5br14d6 8c l0zguj( d$^S$ . 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:dy3 y. 67xm1 q7qqqdlb *fpym a male cat that is homozygous for brown, long hair and1.yqp737 :mly 6qmq d*qfdxb y a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacsk5q-cbv -w+cp l lpt38mt,w(um officinale), the allele for diamond-shaped seeds (D) is dominant over oval-cw-35 vlt 8bpks+-c,m q pwt(lshaped 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 h qh37i wk5ull)air (l), and curly hair (C) is dominant to straight hair (c). A tesqil37kuw )l5ht 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 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 inherin jgmcaz/)) fl 60zr.rtance of the condition shown in the pedigree chart bela)mz6/z lg n 0)jfrr.cow?

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

  Which of these statements about genetic disorders is/are correct? n t7g44fwtj 3g

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 sho 6-6bpz,kedtkn(m 2p9sy+u+ty im; vnw 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 inherit-y cpk44j. 3x+fyakx eance of the disorder shown in the pedigree chart is X-linked recessive and not autosomal recessiyk4af k +jp.-x4 x3ecyve?

  Different species of ldjv7rew (jaf -7pzfsq;(x /t, iving organisms have different numbers of genes characteristic to them. The tex pdtf(,-(s w vr7jz;fja/7qable shows 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 character )p reyz4yaz .a g/i*htt+ao+8istics of pea plants, 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 these statements was8azr)at/i4h+y*.yea topz +g correct?

  A biological male with hemopa .ik(le246c9 +xz jcloqo9 vphilia and a biological female without hemophilia have a daughter without hev+ea9 lqz(. o9cpl2xck4o 6ji mophilia. What are the possible genotypes of the daughter?

  A dihybrid cross was carried out between two sunflower plant)g7kqc w9 ki3d7f6 yz0 e7lkox,d7 navs (Helianthus annuus) to see if the genes for seed number and seed shape are linked. The critical7ne i77kk d,dl xqkawgc0f )9yzv3o 67 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 andvm aag/a2)c q6 blood type B can have a child with blood ty6 agm ac2qa)v/pe O.

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

3.Explain the role of inheritance in genetic diseases.