A man and a woman have a daughter a22x 7 qq4)voj-qlcro gnd a son. Their daughter has normal vision, but their son is colourblind. Which one of these genotypcqjx7rlo2 2o)-q gqv4es could be correct for the biological mother?

  Which diagram shows the sex chromosomes o(pt94j:o .mr-auj*hka 0q zekf a somatic cell in a human male?

  There are two alleles for flower colour in b xamz;6x e7l:c xhe51snapdragons. However, the result of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red, white and pink flowers. Which is the mosxxl 61c :;z5hb xeema7t likely explanation for this observation?

  Which keyword is matched to the correct defin tl sb(1)(ixdk(vrni72q67 dskc(ev xition?

  Which of these statements is a correct definition folt6u6b;g9f gm r a gene?

  The diagram shows a pair of homologous chromosomzys1) m(. ixzaes.

How many loci are shown?

  Two individuals, heterozygous for a specific :6.wdd d*ocp vtrait, were crossed in an experiment. Which row shows thvodw* : cd6.dpe expected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti alle0 vshbvxqlsk.(5);rs z k3xk*le causes individual hairs to have a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who are heterv)lb sh z0 xv3(5x. k*;skskrqozygous 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 (,x08zp rxo4zzq c3ud(1darcvidual pea plants was either round or wrinkled. The results of an experimental cross yielded 315 offspring withd 0dr ,aqcu1(z o8zxcp(x 43zr 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 melano., 1knq8iggidg dom 93rs ksf4u3,y a*gaster) have 8 chromosomes. How many chromosomes are in a fertilised 3g i4d9,gdo3i.sa q 1ngkruk8m,f*ysoocyte of a fruit fly?

  When does the random orientay my8duz82;.8t dtikk tion of homologous chromosome pairs occur?

The majority of the genes in the human genomec 10ps6z k(olx have already been mapped, meaning the exact locations of the genes on chromosomes are known. The diagram bl0zok61 xsp(celow 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 ofx)o5:k4ga:;fa p zk bf linked genes?

  The diagram shows a karyogram of a brown male rat (Rattus ndt9f*/u1yls(mt o5ns orvegicus). Which arrowuls(t y* / odms9tn15f is pointing to a pair of autosomes?

  Mendel observed that there are two possible variations of fstakd1px/12uq5y ypsg*. s* jlower colour in pea plants, purple and white.p1atx* 5k2s jsu1/pq*d.y syg 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 weig -yy0vlz )uop7ht of children born in London in 1991.-) yzovl7u0y p

  Which of these traits is an example of continuoljxd8nrc 2 f/,us variation?

  Which row correctly describes diploid and haploid cells5pullp. 7*ett in humans?

  The following table shows the diploid /1rq spxbx 3h8k5 il3achromosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a r,, ,ygil w tfn4s6ac)becessive 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 child with blood type O. What are thr4tq:m oth;p +e possible genotypes of the biologica+ ;:q4mtr pothl father?

  Which row shows the correct annotation q2lddd)m4 fvk 3 ,x*zeof the alleles for blood groups?

  Which of these statements are trxm4e8s,s rry- ue 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 malariag;ua4,z.ctz aqbl m 90 across the continent of Afric mbt za9z,ql4.gc0 a;ua.


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 coragy45d ev ;e+lour is determined by a number of genes. Brown colour (B) is dominant to sandeva+g5ryde 4; y 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 betwee-k1ccs)) va5fdyb 2evn linked and unlinked genes.

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

Sickle cell anaemia e1yjz4e.e9n/avj x- n*xf vn9is caused 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 ntxk4 oy 3;q1-dbtz4h9fw i3lpn0ge8cross between a male cat that is homozygous for brown, long hair and a female cat that has blawg43yp;d91 q4 0t - zonxkienh flbt38ck, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamond-shaped seeds (D) 923vzgwt8p ;bdf nk/mis dominant over oval-shaped seeds (d) and the allele for long seeds (L) is dominant over s kzd;gpb 9w238/mfvnthort 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 (Cavi+w9+p nhu7fmu)dx kq e5,sn b*a porcellus), 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 te)sfx 5dm+en* +9u bwun ,kph7qst (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 1oizhkbuc*b v ) fg19x9vxn0e: q, o0ithe condition shown in the pedigree chart g,u:xh 9ei1f*9qbvo0bi1 )0nzkcvox below?

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

  Which of these statementolr wdnj +hm ,)p-9 z7yg+fyvb+)zrq/s about genetic disorders 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 shzpjspjl 0x0(ek v-.5jow 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 in the pedig-smdbs )v: f6-9uajhsree chart is X-uhv6-9 s-) bsmadsf:j linked recessive and not autosomal recessive?

  Different species of living organisms havi fb )34b z7bq(lm*64ppkm0rb n fgbx/e different numbers of genes characteristic to themp4b 7b0 (gfqmpbf *6/ )3bblx rzm4nik. 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 characterc+o/zz n wn8p 948dwklistics of pea plants, including flower colour. If the pea p4 9nozk8/w+dn l8zcw plants Mendel was studying can only be white or purple and follow the rules of Mendelian genetics, which of these statements was correct?

  A biological male with hemophilia and a biological .wpkc82 szuet (o y)i3jq -n ,m3us6fzfemale without hemophilia have a daughter without hemophilia. What are the possible genotypes of the dauuime 263qzp fn8y3z ktcuw j-sso (),.ghter?

  A dihybrid cross was carried out between two sunflower plants (Helianthus annuug+dd2zkc9xyf2m1 q r/,tjuw2s) to see if the genes for seecd2z1fdq t2k92 jgm ur +/,xwyd 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 bloomg2 i9wzi6*jdx,prp 6 d type A and blood type B can have a child with blood type O. 2dijxi6 m6gp9z,rp* w

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

3.Explain the role of inheritance in genetic diseases.