A man and a woman haxx-28puagh7t ve a daughter and a son. Their daughter has normal vision, but their son is colout 78g-p2hauxx rblind. Which one of these genotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somat xdm/evi-p; 8 +wrezd;6an oh;ic cell in a human male?

  There are two alleles for flower colour in snapdragons. However, 9/(zpcwcv(k:ixpwm+w j/ (ok the result of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red, white and pink flowers. Which is the most likely ezk/w9 c k(j+omw(/:ic pvwx(p xplanation for this observation?

  Which keyword is matccd;yql-k7dejb qoj7,d2pz y 5y)-t9khed to the correct definition?

  Which of these statements is a correct defiha.rad0/h j5/fqc gq0nition for a gene?

  The diagram shows a pa+f zk4saq;f* rir of homologous chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were4 wd;i(hd4dsi/3 h6rsmv skr) crossed in an experiment. Which row shows the expected phenotypic ratios of the ok43ris6sdim)h wr dsv;/h (4dffspring resulting from this cross?

  In some animals, the agouti allele causes individ0z( /2l rqo)+wjcfmw. b, ,snp zsfpq.ual hairs to have a banded pattern. The non-agr l0(wn)p+js.2mz,fq,b. o scpwqz/f outi allele causes hairs to be a single colour. 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 indij:0l z 3me-xot,5 pekyms9,gividual pea plants was either round or wrinkled. The results oi-y:kgp ,xlje,039 5ommts ezf 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 chromosomddy8vk8v ( - xq:;hfs2yecdv+es. How many chromosomes are in a fertilised oocyteky2 (;xqvd8 -ddsc v8vef+hy: of a fruit fly?

  When does the random orientation of homologous chromosome pairs occur?h1z qzdcd+8 5w/no-0kc gcx j.

The majority of the genes itysd6,; g ybdar z-e0:q9,q nln the human genome have already been mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one representation ye;a g9yb : ,srdqn,0-tld6 qzof 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 definition of lb5l9o +lh nbpnpgz ;k3zok(:,inked genes?

  The diagram shows a karyogram of h qmd7 9cil;4 as9;htk0 h,neua brown male rat (Rattus norvegicus). Which arrow is pointing to a pair of autoqh;e97ns hilt0m9 h 4,kucad;somes?

  Mendel observed that there are two possible variations of nj* 9zp((+ op*giae -eyy (yewflower colour in pea planp yzo*e- gp+(ye(w( aine j9*yts, 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?

  The graph shows the frequency of birth weight of children born in Loh* t)6i7tjotqndon in 19916 t7t ihjqt*)o.

  Which of these traits is an example of continu f +c m(*vfagcb58bk.ious variation?

  Which row correctly describes diploid and haploidwrqek/o cdnh;cwpb :s i 50(25 cells in humans?

  The following table shows the diploid chromosome number of a range of specex:afum0ss j1gqo 8,8ies.

Which of these statements is correct?

  Sickle cell anaemia is caused by a reces+hov: lanbv55 or01gwsive 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 xds*ot6i0nj, f 3i tb1child with blood type O. What are the possible genotypes of thent todj* 1i i,30fbs6x biological father?

  Which row shows the coznubuu+dva n5k,,-k8 rrect annotation of the alleles for blood groups?

  Which of these stateme.w qhlxelnew.y+ z+6 - so7ez.nts are 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 of mala)sw) 0u7qvesb 2s /+an w3xncoria across the continent of Africa.n c7s+0o/sw sn2 ebuqvx)a)w3


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 number of8fx1:kr t6 ejf genes. Brown colour (B) is dominant to sandy crkf186xjf t: eolour (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 unlinkedhgg7wy.a* ev . genes.

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

Sickle cell anaemia is ca+-hj vb7kxikl0(nx /r8xf iu,pl i21eused 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 be8+c5 m22 ubkpixkd xv8tween a male cat that is homozygous for brown, long hair and a female cat thp+imkv c 52 2d88kbuxxat has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxar kvx9. e:wn, jhk,rc( a(gx,zcum officinale), the allele for diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) is dominant over short seeds (k, ((9 rx,:c ,n.rwvxhkjza egl).

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 dlu8 :re1r2ebyi9 q k wtjy+w.1:imzq4ominant 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, straighb4 9:wrj:q+z1u1ytq. yi8rmw l ee2kit-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 of the condition shown in teh;)9a9l83 ,nau 0 wwrzq rliahe pedigree chart berl3;,nr 8al9qahai wu wz )09elow?

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

  Which of these statements about genetic disordeq-s*ws 6j (ia/o0uap 5l;8-7ntauq 8dnunkltrs 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 tx5g5z z:vzx e8raits 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 disorder shown ingm js 5x3u0 (w6eeymx(oz6uh; the pedigree chart is X-linked rwh meueuz3;o((6j6 xg 0smyx5ecessive and not autosomal recessive?

  Different species of living 2h hlq,g ;.5zcdzwn1p organisms have different numbers of genes characteristic to them.cwznhg qh, z 15pd.;2l The table 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 charact i y lxmh2-(h;1o;jkeleristics 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 om;x-l ;hk(i 2l jh1eyof these statements was correct?

  A biological male with hemophilia and a biological female without hemophili 4bgivfc9 mn or)/c2b:a have a daughter without hemophilia. What are the possible gbc 24f n:vmc )i/o9grbenotypes of the daughter?

  A dihybrid cross was carried out between two sunflower plants (Heliantk h+kds,f-jt1 hus annuus) to see if the genes for seed number and see-kd 1tskhj ,+fd 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 wi*mzb59o,bqma toj.56bj jd/ nth blood type A and blood type B can have a child with blood tqz5 6b/oj5t.o,*jdmbj9 na bmype O.

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

3.Explain the role of inheritance in genetic diseases.