A man and a woman have a daughter and a son. Their daugygf. sj647 8ujmbaj9thter has normal vision, but their son is colourblind. Which on6 jjf.ts48b9 yujg7a me of these genotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic cell inro6 -ikf -a3qh. /k93qlreeq i a human male?

  There are two alleles for flower colour in snapdragons bk87av. (qzpvo-v ft2. However, the result of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red, white and pinkqtk2.a8bo7 -zv vpf (v flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to the correct defi5lryzoev; c8/nition?

  Which of these statements is a co.b+ zg oa2wm/rrrect definition for a gene?

  The diagram shows a pair of homologous19p d8wzppl:j ,thkbst :3 cl8 chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a spegq z,nh9ij:f 2ssav /y4f,sa(cific trait, were crossed in an experiment. Which row showssqshi4 f y2zjgsf :, naa,9(/v the expected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti allele causesqcrq 94z4hlze l2:5r d 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 pattern.el:5rq24r zld 94h cqz

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 indivcu1o 5 pna-lt1idual pea plants was either round or wrinkled. The results of an experimental cross yielded 315 ofun5 a1 cl1pt-ofspring 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 (eh+ 8qpf otp4a b x;2dtf)33;a/dhl jmDrosophila melanogaster) have 8 chromosomes. How many chromosomes are in a fertilised oocyte of a fruilohaaep;2 8f /p43d) md+;qh3jbt xftt fly?

  When does the random orientation of homologous chromosome o 6a eh;y)d- .mhfxmfxvf/ x/6pairs occur?

The majority of the genes in the hm: v anpuvc(zu6vx 2-*uman genome have already been mapped, meaning the exact locations o:-*vuv6upnz2 xam (vcf the 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 definition of l5ta, uyynn 7rl +z,r5-x; tjpeinked genes?

  The diagram shows a karyogram of a brown male t 6rgksr+e 98f k8a1g gbtn2k9rat (Rattus norvegicus). Which arrow is pointing to a pair of autos grkk96gt sbfne1akr+8t92 g8 omes?

  Mendel observed that there are two possible varial/:wfo mrju5:din rx6 /1 pq9(tqom9vtions of flower colour in pea plants, purple and white. After a genetic cross, the ratio of plants with purple flowers to white flowers is 1:1. What rq tn:/ (qo1dwv6m9j/xiru:9 f m5lopwere the genotypes of the parents?

  The graph shows the frequency of birth weight of cyh) hazl /n0:children born in London in 1991:y/ hcl 0a)nzh.

  Which of these traits is an e.y9g4o/rb :p;)ftnur3ou z baxample of continuous variation?

  Which row correctly describes diploid and haploid cells i.glj7z 3.l cgvzqa-: ya)9 64uu nhuipn humans?

  The following table shows the diploid chromosome number of if,ok9 ;i0ffqa range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive allemip pn(;w6 as+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 w2cix o980tha yith blood type O. What are the possible genotypes of the biological fatheroyta9 xc 2h0i8?

  Which row shows the correct annotation of the allelezbo s)kzrz / pec,jd+8x: zciog7f(8p4l3-x us for blood groups?

  Which of these statements are g4m h3ms);vuhtrue 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 (l 3vd d*prq8w74lc4ug, qe hasickle cell anaemia and the spread of malaria across the continent of Africaal , g prwdv*ql c8d(4ueq4h73.


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 determifzl; 8 y*h-qfjlz :jr qxbj);:ned by a number of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) colour (P) is dominant q-)r: jjqyh;zjzf l*f lb 8x;: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 betwee )zx(4g6m yxx b*gpg,8mvm o1-d7rtz on linked and unlinked genes.

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

Sickle cell anaemia is causedu bd:lb )zsv a;g,yx8(h/p)c d 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 between a male cat that is homozygous for b s,t0b3lht/)cb x6o b7w7 ekmirown, long hair and a female cat that has black, shorio3eb hc)l/77,bsw60 tmk tbxt hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamond-shap:d/lse5q1yoo 3 e z0t/wpuj ,led seeds (D) is dominant oe qll 1owz/ souy3:ej05d,/ptver 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), long hair (L) is dcoc-f1 l97(vfh7f4l*v gxurmominant 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 carried out on th4u7 ho(l9vcffrv- xlc1 m*f7ge 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 pedigr+lh;s+ 9z evrvee chart belsv9 +z+; hvrelow?

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

  Which of these statements about genetic disorders is/are bki vr tg40:4sq7hb (wcorrect?

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 ;y6b-j)as wu z+efw(w 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 tho*j e rit.-sp6x/uhz 2e inheritance of the disorder shown in the pedigree chart is X-linked recessive and not autosomal re/rz*p-s xt6oe hi. 2jucessive?

  Different species of living organisms have differenzebsebpujtfpf*p0) 4 ;)g,i 2t numbers of genes characteristic to them. Thejzpfes*i;)e u4 bt, 2g b)f0pp 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 characteristics of pea plagsxha7 / bha6+ 1ra0vonts, including flower colour. If the pea plants Mendel was studying can only be white or purple and follow g61h+ /7sa a0ahorbvxthe rules of Mendelian genetics, which of these statements was correct?

  A biological male with hemophilia and a bw ay6p h(2b(uliological female without hemophilia have a daughter without hemophilia. What are the po6p l(2hu wy(abssible genotypes of the daughter?

  A dihybrid cross was carried out be,s;nhx p2t yhd :hf)1atween two sunflower plants (Helianthus annuus) to see if the genes fys;)h t 2fh1xnph,d:aor seed number 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(o pke38wse er*;br .j blood type A and blood type B can have a child with blood type Op (rwer e*ob.e j38ks;.

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

3.Explain the role of inheritance in genetic diseases.