A man and a woman have a daughter and4q-l4 zhhvdx dxm..9 s a son. Their daughter has normal vision, but theirm.l4- svxdqhxzd h9.4 son is colourblind. Which one of these genotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic cell in a human ma b0t-cbvo f)vhs(gg98le?

  There are two alleles for flower colour in snapdragons. Ho7*p i-w*c *lp7obnk qlwever, 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 explanation for this observat*qpb pc*n *7w7-kiollion?

  Which keyword is matched to the coh6 .6rdy d*cbdrrect definition?

  Which of these statements iz9a ovt hc hnsup1y9/4:4nq5fs a correct definition for a gene?

  The diagram shows a pair of homologous jo8p ; 64cuxw7qfwgi:,, xaruchromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trgsmqahbsxv5+0rptd:f3 ,rkti :./0v ait, were crossed in an experiment. Which row shows the expected phenotypic ratios of the offspvqghm f5s+03.xiprskbda tv/, :0r: t ring resulting from this cross?

  In some animals, the agouti allele causes individual hairs to hav v4z:y4-orxo we a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who are woov4y : -z4xrheterozygous 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 indi *u:t3k,mqg8sny)pw mvidual pea plants was either round or wrinkled. The results of an experimental cross yielded 31w:knuy3tmpms,g8) q* 5 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 f;u+s2moahmx/hi / (tykh (;usly (Drosophila melanogaster) have 8 chromosomes. How many chromosomes are in a fertilised oocyte of (h uh 2/km(+t;ia ;somxy /usha fruit fly?

  When does the random orientation of homologous chromosome pairs occu w2 ja c5v7v7b+blljg-r?

The majority of the geny7 m,wan t/arfk0)ah 3es in the human genome have already been mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shknay 0/wm,rat 7f) 3ahows 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 deflksg u1g +5c 7)r1zcen9w f:cs65j vmiinition of linked genes?

  The diagram shows a karyogram of a brown male rat (Rattus norvegicus). Whit+ebbuzj u;nb,*nnx kaw)9 6. ch arrow is pointing to a pair of autosomn .;utb)k69jzn ub ax*, bwen+es?

  Mendel observed that there are two possible varhelp+h)oky u 4a 30;priations of flower colour in pea plants, purple and white. After a genetic cross, the ratio of plants with purple flowers to white flowers ip;k oy hp)r4uh+ea30ls 1:1. What were the genotypes of the parents?

  The graph shows the frequency of birth weight of children born inj myq/hd(*d 3p London in 1991.d/(*j pmyq h3d

  Which of these traits is an examp;bavpfuhbtb c. g gj9/37i 1:ale of continuous variation?

  Which row correctly describespbz -y5 fxgy lcgj-+m/. (2bvc diploid and haploid cells in humans?

  The following table shows the diploid wx;; fr/7 ga6n+wdroncqy;:rchromosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive allele r f y ejgihs;(u1vt7(i1r .kw.(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 wn lx4kv pjig1q9 z0wh+l77i7l v0-- .tpwrl qyith blood type A had a child with blood type O. What are th+wxh4 .0p- -vi9wkqlnr qll7 p10lvi ty 7gz7je possible genotypes of the biological father?

  Which row shows the correct annotation of 5csh x 4):y 6 ifl39tbdcl/i6md6badk the alleles for blood groups?

  Which of these statemep-6tnx k0 zfw6nts 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 inc4+wfc 66ox najidence of sickle cell anaemia and the spread of malaria across the continent of Afric of aw+6c46njxa.


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), n)prcob /h(b8vi)(,q 5 iopu o aq78jkfur colour is determined by a number of genes. Brown colourobc p8ju5,ko o hiqb(8(i p)nv/qra 7) (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 lio6qyuom*q90 *1dlnen y l) hb/nked and unlinked genes.

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

Sickle cell anaemia is caused by the allele x di(.5g:qfb3 3t3b cwmz9* caewug-tHb$^S$ . 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 betwqkju++ij;v3b nl t0n:een a male cat that is homozygous for brown, long lnjj0i+ ;+3 qnk tv:buhair and a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamonut:9cq 5i a2cvr +k0qzd-shaped seeds (D) is dq:uqr0cva95ic tzk2 +ominant 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 porce /dqdip7h..z ,p(cof vllus), long hair (L) is dominant 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, straight-haired guinea pigs and a chi-squared test (χ2) was ioc(zvq..f,/ppdhd7 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 the p d t1. een/hktar-jz-3edigree chart bel / 1-rh-3 kdtnze.tjeaow?

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

  Which of these statements about genetic disoguc1mp75m ka /lx2 4oirders 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 ai/2 :0*,nuof, plimc a;uwizb co8i3x7wje )k 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 t hucut:-qdi36r(f mn9fwai, 3he disorder shown in the pedigree chart is Xh93i3f-urtumaf w:(icn6q d , -linked recessive and not autosomal recessive?

  Different species of living organisms have different numbers of gsz52p 9a yo.9t31qjyo/r wxf penes characteristic to them. The table shows the estia9y3 /forpw2xy. 5z9 p qj1tsomated 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, includindm /ce *nq+ke,g 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 wam qdnk, c*e/+es correct?

  A biological male with hemophilia and wo 8fv .- px(iysc4op/a biological female without hemophilia have a daughter without hemophilia.y/xowp4 o i. sp(v8-cf What are the possible genotypes of the daughter?

  A dihybrid cross was carried a 8wutinph4evrzr7 7*q*2u2l. w)d obout between two sunflower plants (Helianthus annuus) to see if the genes for seed number and seed shape are linked. The critical value for the chi-squared2i orun *tdh.q27z8ru *)vw4pawl7b e 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 a il;b9xfkq80ti h, d8az)6brand blood type B can have a child with blok9,qhbb)xf;iid8alt6z 08ra od type O.

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

3.Explain the role of inheritance in genetic diseases.