A man and a woman have a daughter t5e e tty z u jae7n,zj:)dxvg/)h37k;and a son. Their daughter has normal vision, but their son is colourblind. Which one of these genojt,:jg;)t )azv3y7k/ ezxu e5hn 7te dtypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic cel;g h-vv50yx): o psvpwl in a human male?

  There are two alleles for flower colour in snapdragons. However, the res:b-hwkoa76*9 kqa ywl ult 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 observatiwb a- hlyk9ka:o*qw7 6on?

  Which keyword is matched to the cj8ry *-j blr(worrect definition?

  Which of these statements is a correcxt 0fv8lsc /5bt definition for a gene?

  The diagram shows a pair of homol4m4fyof v) 3nhogous chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were cr0xxfl0ub 6 ,yx) lpvj6ossed in an experiment. Which row shows the expected phenotypic ratios of the offspring resulting from this cros0 b)jx,v6luyx6p 0 lfxs?

  In some animals, the agouti allu,+riz(3lo4d mr*l-r lt 9p ejele causes individual hairs to have a banded pattern. The non-agouti allele causespzr3+jor 4l led 9r,(li *-tmu hairs to be a single colour. Individuals who are heterozygous 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 individual pea plants rtk rny,r-0n0 was either round or wrinkled. The results of an experimental cross yieldedr0y0k,tr-r nn 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 (Drosophil2 eahj 9sszg)z:o xc;* g)ktgby* /z2ka melanogaster) have 8 chromosomes. How many chromosomes are in a fbj xk;ygo2cz)hks2* 9te :)s/zag gz*ertilised oocyte of a fruit fly?

  When does the random orientation of homolog4* ;cha+lvg- spc6nh vous chromosome pairs occur?

The majority of the genes in the human genome have already been mapped, me0 3r 9ovjyuns6aning the exact locations of the genes on chromosomes are known. The diagram below show30 s rj6nvy9uos 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 oz.2u4rtyln0cai 9;,ggk x. iaf linked genes?

  The diagram shows a karyogram of a brown male rat (Rattus norvegicus). Which a s/ 6ynne8xo9grrow is pointing to a pnesy x96/8 ognair of autosomes?

  Mendel observed that there are twoswj 7 reuj;4+j possible variations 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 were the 7 we; suj4j+jrgenotypes of the parents?

  The graph shows the frequency omyj*3;wv dqth* -zezs+(; vxof birth weight of children born in London in 1991*jxdz(-+w ehz;yt;*vmsq o v3.

  Which of these traits is an example of znl -r l7t kzx4umthb.)8)dv*continuous variation?

  Which row correctly describes diployt k-i4hvbp07pc8o8 n id and haploid cells in humans?

  The following table shows the diploid chromos42oz8xmor bbv lz)c f s+9ck8,ome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a rec-n. gku.gr* yljis/ o5essive 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 ch n5xdrav9y;8x am -r6cild with blood type O. What are the6vcxxmn 85;aa d-9 rry possible genotypes of the biological father?

  Which row shows the correct annotation o3ywlr6;kkjev)* + y f-x cl+ssn.c 2cbf the alleles for blood groups?

  Which of these statements)p*wf(9r z:,xrk orpt 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 incideno 0wk 3cyk*8twce of sickle cell anaemia and the spread of malaria across the continent w0ktoy8w c*k3of Africa.


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 determined by a number ofel zb 52x:uv7+x1s zoz genes. Browz5:zu x+vb7e xs 12zlon 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 ld*rbnpui z /sb7,tq wm7.1zubw/ ,d1p inked and unlinked genes.

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

Sickle cell anaemia is caused oo f7u,9hu9.unim llk7l(k/v;uvp7 vby 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 f:a+e;xdey854x5u /xqigm vk uor brown, long hair and a female cat that has black, short ha5 ue +mu/x8 kxx;4vedqg:ay5iir.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele fo5jyafylh8r /mf2wzp(./z0 w ab f7u r6r diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and thj(lmu8.5y 7 r/ahaz fpz/6 rffwwb2y0 e 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)*y 4vk c*pu+dd, 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) waskcdv u*4ydp +* 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 pedigree -utidg/uag jo.* ae94,tex.h1h zg3rchart-t zx.r 3uut1g hied/g,h g*a94ea.o j below?

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

  Which of these statements about genetic disorders is/ary8u3eh cu+ )ype 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 normle7j x1f) maw)al 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 disordes6fjxh0 yt0w5 ru-bz:4get b2r shown in the pedigree chart is X-linked recessive and not autoso:56ghtt e-ux0yzwjsrb4fb 02mal recessive?

  Different species of living organisms have different numberxwmw 2ollaj g j-3 ns*o+s/(0 ev5pdy(fn5k3qs of genes characteristic to them.53m5+ -qos xe (n(fjloyww2nsd/30k g jlvp*a 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 characteristics of pea plants, inclu+7d agsi ( t2a9h;riljding flower colour. If the pea plants Mendr; i7 ia9l2+jadgsth(el 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 8 c:om/g2zmzx28imap cls:/ p and a biological female without hemophilia have a daughter without hemophilia. What are the possible genotypes of the daz ps mxacpc/82o::mli2/zm g8ughter?

  A dihybrid cross was carried out between two sunflower plants (Hell*mt5 bon trqvq)x 75),nbl *yianthus annuus) to see if the genes for seed number and seed shape are linked. The cr5,7v y*or5* n xmb)lt)qtlbq nitical 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 type A and blood type B can havwyq 8+fa+snkbq k zp6j7c6iqd3*.*ej e a child with bljwik+d+qnb *qz.6*eac7 pf 6sjq 3yk8 ood type O.

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

3.Explain the role of inheritance in genetic diseases.