A man and a woman have a daughter and cmx0qw fk.);ov4:*o*v+svcfff j ud 8a son. Their daughter has normal vision, but their son is colourblind. Which one of these.f;w)8*fsvjouc vc 0 +f : mkdqx*4vfo genotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic cell in a human d v- h.k4hd2zfmale?

  There are two alleles for c+jo08ks 4,9j06myuizgb)p7fo foikflower colour in snapdragons. However, the result of a cross between two heterozygous plants yielded offspring with three different observed phesojk zfu6 i8,jfkc+yp0790gmo4) obi notypes, red, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to the correct 8.; vo7bxsb xodefinition?

  Which of these statements is a correct definition forh.q j63a0zm/1znxjbl bvy/uvb v8 ; x) a gene?

  The diagram shows a pair of homologous chromos reyv0jl5qs4r,o s:1momes.

How many loci are shown?

  Two individuals, heterozygous for i 0yu;gh3vr4m alo1g:a specific trait, were crossed in an experiment. Which row shows the expected phenotypic ratios of the offspring resulting frugy3i0;1rg 4v:a hmo lom this cross?

  In some animals, the agouti allele causes indivtubr9pt */q/de8 d3ur idual hairs to have a banded pattern. The non-agouti allele causes haiubet * qd/3prt9u8r/ drs 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 p6wdtb )//o 54qblntw 55 c kgxm.vma5sea plants was either round or wrinkled. The results of an experimental cross yielded 315 o5/ogx5 cq 6)s5/vdn5t w mtb4mak.lbwffspring 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 (Drosophila melano i9 cyt7/skxl;gaster) have 8 chromosomes. How many 7 ci/l; sykt9xchromosomes are in a fertilised oocyte of a fruit fly?

  When does the random orientation of homologous chromosome pairs occu kjd:7,nnlbc)r?

The majority of the genes in the human genome have already been mapped, me wfx,vu+n.)inu7jbd6 qz0-alaning the exact locations of the genes on chromosomes are known. The diagram below shows one representation of a homologous )u.xzf 60 + bwi,uq- 7vndjanlpair 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 definithi ./2pd lip;tion of linked genes?

  The diagram shows a karyogram of a brown male rat (Rattus norvegicut-r7 d 6,igd2k1nsjq ls). Which arrow is pointing to a pair of aut 2ld-tjirngkq,7 ds61 osomes?

  Mendel observed that there are two possible vari5tx9 t o3xpjm,bwv go7.c)17 x r+em7wyydou3ations of flower colour in pea plants, purple yjmxe,p .d 1ot+73)xr9wb yx uwm7c3 got57ovand white. 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 weight of children born in Londoqe i x jju.t(s;88*0k8d7u 3kqhnpv cun in 1991. 3q;j 7vnqkuu8s dp0.8chk ( ejt xi8u*

  Which of these traits is an example of continuous variatq.8 7 f+rr get0g/yfpaion?

  Which row correctly describes diploid and hd46 ghkilbm )-aploid cells in humans?

  The following table shows the diploid chromosome numy/f8v.5);h1w g5wcx kxwac paber of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is cause5 u3/a imw ,gddocs*/ bsfj kkg-:a9g.d by a recessive 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 wyv3/d svk8jrm uucmo03ry281gfq6vn4 yp : - lith blood type A had a child with blood type O. What are the possible genotypes of the biological father? 36c3yf:nvp 8uyr0k8u -dvy o jr ms4v gql/m12

  Which row shows the correct annotation of the alleli.o yh8v 1 )oqq-p7hmiop t91oes for blood groups?

  Which of these statemen,6zer ;btm -xvts 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 incidenmukzcr 5;+l8 gme0i y2ce of sickle cell anaemia and the spread of malaria across the contine 8i0ge2ukrc ml+yzm5 ;nt of 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 prg*t6 (dqxvla;i5ka ru4 *aw3 gzewalskii), fur colour is determined by a number of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) colour (P) a6gqvud3w4a rt xa*5(i *kl;g 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 f rkm14ctbu3w)ait b 7g3uj.2 nu6ic4unlinked genes.

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

Sickle cell anaemia y+7sgij / ;(luo ixf3fis 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 cross between a male cat that is homozyr+f(th9clz3 5xru we)hh8p s -gous for brown, long hair and a p (rez+c3ht5hs-f 89xur w)hl female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the a wh9coai/udk* f7d v97llele for diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seedf ak oivdh9/cw9du77*s (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) -pg08pg 2vkn1i dbt tfc9( 0vris 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 nbt2- c kgr0fd(p9v80 p1gitv pigs and female short, straight-haired guinea 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 shown in tibj:5a j1ump+ :zmu o tx+wv94he pedigree chart bel:4om 5t+:mu b9 p j+vaj1zwixuow?

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

  Which of these statements about genetic disorders i ,ee,:0 cbf1pxiy;dfi4m3 koc s/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 a normal distrdpg2fov:2fm(o e7 v;aibution.

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 pedigree cha3lgj3zm hc,c ;fac 8kc7kgdx2 r.4d *prt is X-linked recessive and not autosomcx4*;p8zmk 32 ja. k7,clrdh f3d ggccal recessive?

  Different species of liv pqg1je)uswl(83*fighz)dw 3 t4k 6iz ing organisms have different numbers of genes characteristic to them. The tujhszq w ik1e ggz8d( )w36*)fp3 i4ltable 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 pla-mxer,tta 0usl3lxf: (k;7jbd i88p pnts, 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 statements was corsi-d; :(jp8bf7 lrmuxea 0 kltt,8x 3prect?

  A biological male with hemophilia a.5i9o4p5ozm xkn f jb7nd a biological female without hemophilia have a daughter without hemophilia. What are the possible genotypesn4ox.k97zfi5m5 j bop of the daughter?

  A dihybrid cross was carried out between two sunflower plants (Helianthus an0fk+0lof 6cqsv6 8xzu nuus) to see if the genes for seed number and seed shape are linked. The critical value for the6clzq0o kfx0 f+s68 uv 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 blo +lw+zl*-lhd kib*0ftqo it1cjt ,b8(od type B can have a child with blood typeczjh t,*- qtol *l+dbi8 k0b(1l+tiwf O.

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

3.Explain the role of inheritance in genetic diseases.