A man and a woman have a daughterxujnx)*dg c*wo fnf/)pec(, ( and a son. Their daughter has normal vision, but their son is colourblind. Which one of *)(pexf/ n dujwc*, n ogf)cx(these genotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic cell in a human maltn) d+l+tf ch0e?

  There are two alleles for flower colour in snapdragons. However, the resuuvu)fn 8/,ia2 ad,4c5cqopf jlt of a cross between two heterozygous plants yielded offspring with three 4c/ ajfi 52c dpa8)no,quv,fudifferent observed phenotypes, red, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matchijg4 (t+hh ls5ed to the correct definition?

  Which of these statements is a coe:j,09e3 uy jaixp+ dvc,:ady rrect definition for a gene?

  The diagram shows a pair tyekz9gum e0 * xdsoz*7 32(lsof homologous chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were crossed in9omp5vxgp*- b u.f0gm an experiment. Which r f.bppv5g 9gu*- xomm0ow shows the expected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti allele cauu1( sy4pi6gltuw .v g2ses individual hairs to have a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who are heterozygous have hairs with a banded pay .2 suug(4gtv1 wlip6ttern.

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 individual peap)vsy14 c. whk plants was either round or wrinkled. The results of an experimental cross yielded 315 offspring with round seeds and 105 offspring with wrinkled seeds)ky1v h wc.4ps.

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

  Neurons of the fruit fly (Droxi6*1y37 df qbloxaspz -3w pq/b p9z4sophila melanogaster) have 8 chromosomes. How many chromosomes are in9dp*3sbpwz 6bxiy /74zo1pl3xaqq f- a fertilised oocyte of a fruit fly?

  When does the random orientation of homostvud o7fs 2t7k634jn,*es cjlogous chromosome pairs occur?

The majority of the genes in s0f1jd-8rrnxlc jv q+6/-9 0oj 0oboso6wlp fthe human genome have already been mapped, meaning the exact locations of the genes on chr- r+ x66-r0jojbf vp9/c0 oj 0 dlsofs8nlow1qomosomes 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 definition of47je0lac1qyp3 /k kcz ;yz8rs linked genes?

  The diagram shows a karyogram-n6 l/holwye,5isnv,ae d8d6 of a brown male rat (Rattus norvegicus). Which arrow is pointing to a pair of autosomn ,ea8wiel 6l5/-6o , hyvsdndes?

  Mendel observed that there are two possible varia(l*q3+npu(co aw k1ki tions of flower colour in pea plants, purple and white. After a genetic cro(kk+paul*i( 3cnw1 oqss, the ratio of plants with purple flowers to white flowers is 1:1. What were the genotypes of the parents?

  The graph shows the f*yr4i-bhn;f+7 x fm mv8ydf f *d1jc8wf*z 1pkrequency of birth weight of children born in London in 1991.dv *ip7f-fz mfwky4 f* 8nh8 x;c*y d1r+b1mjf

  Which of these traits is an example of continuous variationk 0 hbhjgt* 1w/dv7pla8y /ra7?

  Which row correctly describes dip*+h c s*i(bzl( d* njvjb)lh0qloid and haploid cells in humans?

  The following table shows the diploi5y tnd+ onggsgppb998 /eg;3 ld chromosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive allesy; :mva ++o*ffuay9:dio 2le le (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 child wiywk)ewo8)zlntx8vo v -x0t:e(6e+o fth blood type O. What are the possible genotypes of the biologicalv )o tx88l0-e+zofw:oke)6 xvy entw( father?

  Which row shows the correct annotation of the alleles for bloo pcumapt(b5(, d groups?

  Which of these statemvai3co 53-lh fitfl7 (ents 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 spre zhx;xx5sv-vz0:9 j dz;yscs0ad of malaria across the continent of Africa. xcy 0;zvsd ;xs xzhvs5z:90-j


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 coly8hli9a7hw. lku )7fk our is determined by a number of genes7)kkaw u7hiy.lfh 8l9 . Brown colour (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 unlinked genes. re5qe1;+5y8spnbw a ,rj)fge4q2 y ib

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

Sickle cell anaemia is )ss 7d(i 5ufjpcaused 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 b hkfh7 dlpg2i 20ry4c h-/ndjkcp z3y1v2 ;zm)etween a male cat that is homozygous for brown, long hair and a female cat t/c d32yf02- h crdhn2; gyi4h7z)1zl vkjppmkhat has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamondmc;8tt-wcsn+ 6:+gt9nm i ejo q1 ou7f-shaped seeds (D) is dominant ovnewtcc8+7tnjmi:sq6 9f1omog + tu; - er 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), lgcyz wat4 )2vbf *t3c,ong 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 gu)av*c 2ct 4g,yfzbt3winea 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 shfoy(ug om(m;p r26q2r tq ;os:own in the pedigree chartfq( p;r:;m(t 6mo2ugoyqsor 2 below?

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

  Which of these statements about genetic disorders is/are correctvi6x b odkufg+4ib 0:)n,y b;7ux ,lrh?

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 normal distributiou8.v (jqmtnq,nb adyt rm,g/7:0c5 bwn.

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,7,m-p/n2dn o cgdacu disorder shown in the pedigree chart is X-linked recessive and not autoonm,n, 7dcg a-p cud/2somal recessive?

  Different species of livinpw wtsxgb81j7-gq:+ tg organisms have different numbers of genes characteristic to them.gbxtgwp7:s- j18w t+q 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 charaw* m ()vt::mbf fukxn43b+wz y8eq1zk cteristics 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 statemen8fznvk wefb+q (: 3m:wytzbx *u)1km4 ts was correct?

  A biological male with hemut4xipk(wi i(yl6* 3bophilia and a biological female without hemophilia have a daughter without hemophilixw b ityi(l*3i4pu6k( a. What are the possible genotypes of the daughter?

  A dihybrid cross was carried out between two sunflower plants (He z-w k c6yfk(8n)g-kujlianthus annuus) to see if the genes for seed number6j8 (kzyn-cukwfk) - g 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-squared test was 10.05; what does this indicate?

1.Explain how parents with blood ty3 ( ,3.yo+ /vdeum umii6cblibpe A and blood type B can have a child with bloou.bi u (63yibmv+3cdo/, lmied type O.

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

3.Explain the role of inheritance in genetic diseases.