A man and a woman have a daughter and a son. Their daughter has norm; bo (oklanz9)lj27x(s t0 grual vision, but their son is colourblind. Which one of these genotypetxa)k(boszu (27; lj 9l0orgn s could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a fv)knr.rdxcg8 *t+ /dsomatic cell in a human male?

  There are two alleles for flower colour in snapdragons. However, th yd61)y+ix f/wgolrw6e result of a cross betwexiof lrd +y61gww)y/6en two heterozygous 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 corhb4*z +trtl/ y mw/c/grect definition?

  Which of these statements is a correct defi ;e0rscc dk.y5y0q 9jdk(a1nknition for a gene?

  The diagram shows a pair of homologous chromoq6w0sq/:xzp f52jmh8rv7u k tsomes.

How many loci are shown?

  Two individuals, heterozygous for ;kq.ql ynpj/ hg(8bd0 a specific trait, were crossed in an experiment. Which row sho blhqpnj;/0dk(g qy.8 ws the expected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti allele causes individual hairs towf1 ty o.na pehp-y15if;+g6u have a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who are heterozygous have hairs with a banded patternfh61e. w+;fty5a-n up i1gopy.

Which combination of parent genotypes would allow for production of offspring that do not have the agouti characteristic?

  Mendel observed that5 lr*b3yy95 n8pn bcnp the seed shape in individual pea plants was either round or wrinkled. The results of an experimental cross yiy*pnn 9nl5 3pycb8 br5elded 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 melanogaste 08j18pdgigyrr) have 8 chromosomes. How many chromosomes are in a fertilised oocyte og 18jd0pgi8 ryf a fruit fly?

  When does the random orientation of homologous chromo5g: peraph3 t5px:kk 3some pairs occur?

The majority of the genes in the human ge+r e1)pda-mw snome have already been mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows on m)dwrap -1+see 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 definition of linked genr1 h,i:ue o2 elcx+/z+tj+v0,mq bh qees?

  The diagram shows a karyogram of lfus maf6fs5)m9t+8 na brown male rat (Rattus norvegicus). Which arrow is poinaulm )9 ff8 6s+fst5mnting to a pair of autosomes?

  Mendel observed that there are two possible variations of flowe1/1qbxfv :ev3wq fn/ sr colour in pea plants, purple and white. After a genetic cross,sb fx1:v/3 e/ f1qvqnw the ratio of plants with purple flowers to white flowers is 1:1. What were the genotypes of the parents?

  The graph shows the freq 0e:nsf p81zes(n2vfc uency of birth weight of children born in London in 1991. 2n: csz(e1 f0psvenf 8

  Which of these traits is an example of cont.a wwnwm) *r5 sh+km1cinuous variation?

  Which row correctly describes diploid and haploid cells in humv hayylr+b0 2d .n1i:j-sls4 oans?

  The following table shows the diploid c zqjj2gu/72y x15xm-cgl fuo 8hromosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive allele (mc,zpnp (h5h h*7jb7np5i4p wrefo9 +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)5acjl9pmpo ,br /2si had a child with blood type O. What are the possible genotypes o)5 ps ba,9m/2ojrpl icf the biological father?

  Which row shows the correct annotation of the alleles f/ /.ay:g8es9pq0sc ee5d os sfor blood groups?

  Which of these statements are tru1 v s vh55vo3wqw)*dive 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 k ef.2zwr :hof *v:jg0of malaria across the continent of Africaw.ze g :r:*khf 2fv0oj.


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 dete* :o 2f-30l4 wn;x xzowol50qwgbu5a zg q1icarmined by a number of genes. Brown colour (B) is dominant to sandy colour (b) and an oowuai0-0xboq nl x5z4wz 5wg*:;1 32qgaoclf mbre (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 linklvun5e imy63 70vr2 cped and unlinked genes.

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

Sickle cell anaemia is caused by the allele H5z8 uoye 0m1smb$^S$ . 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 n8+e2).h otmgvf0uudrt v g79 between a male cat that is homozygous for brown, long hair and a female cat that has bl2v duegm80tv7uo rntgfh )9. +ack, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamd3e(4y2h zgcekd my3 0ond-shaped seeds (D) is dominant over oval-shaped seeds (d) and tmde3c4yeghyk2 z3(d0 he 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 shopt44t.h:ft bud2v5ek ++ yfl7ua-mr crt 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)dtpu4vt+2l feu7 f.m-5h rt :+k 4ycba 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 lh 21 iu.jkal 0bri.v(, 93kwfxn-r orin the pedigree chartl3r02rjba. .w ,i9 hv ku1n (-fklxior below?

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

  Which of these statements about genetic disordb8vctu6f+s 1 kers 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 traits can show a normaau4mp 0wh0cjs. szvm3 0nv /c)l distribution.

2.Outline the differences and similarities between homologous chromosomes.

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

  What suggests that the inheriteavx 7 1cqc 6bhq)*us:mh ,aj6ance of the disorder shown in the pedigree chart is X-linked recessive and not e)q: x*aqmc6ja 6cv,7b1 sh huautosomal recessive?

  Different species of living oryq67tin sgs8p5u 4 ;9jzt7l umganisms have different numbers of genes characteristic to them. The table shows the esti5z9us8s ;7tqyjp4li7mu nt6gmated 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, in5(koxtjz1- nqz,)sy bcluding 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 was corr)(,5o-1qbny skzzx jtect?

  A biological male with hemophi35 j* nwlrq.illia and a biological female without hemophilia have a daughter without hemophij w .lql5n3ir*lia. What are the possible genotypes of the daughter?

  A dihybrid cross was carryem3rp4 e31rh*)mo g6h :mjjp(m l6gried out between two sunflower plants (Helianthus annuus) to see if the genes for seed number and seed shape are linked. The crg34mmjjym*rh1) r(egep6l po6mr3: h itical 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 bloodtfe fu1+* hc:oeq l0f, type A and blood type B can have a child with bloodf0f ho u:1+q f,l*teec type O.

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

3.Explain the role of inheritance in genetic diseases.