A man and a woman have a daughter drbp8v936 u0f k+ykjdand a son. Their daughter has normal vision, but their son is colourblind. Which one of these genotypes could be correct for the biological moth6vj y3dkkbd8r09+ pfu er?

  Which diagram shows tlk3qf7v3/ wfg.xo6 ljhe sex chromosomes of a somatic cell in a human male?

  There are two alleles for flower colour in snapdragons. Howel5h .y9;tqmchver, the result of a cross between95cyl.q;m hth two heterozygous plants yielded offspring with three different observed phenotypes, red, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to the correct deq,p 7bok1lpp-finition?

  Which of these statemol ke8kwg8 y89ents is a correct definition for a gene?

  The diagram shows a pauc7 r or 798hi+ea4wznir of homologous chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were (hizom+8xf4b)c)+ q. q gfxq2sq +yzp crossed in an experiment. Which row shows the exmp)h2+oxf+cq(y8zibx4qqq s .z)f + gpected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti allele causes individual hairs to have a w 5 1rczp cab2mf8f)f04*secnzkx 2ejuvi4 --banded pattern. The non-agouti p8a iz4-wkzc- mvex2b rs4e1fc*fnu20cj5 ) f allele causes 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 was either round ie+7ai3fuq k3h4m-a:/gpttt or wrinkled. The results of an experimental cross yielded 315 offspringuh/43 +egk- mitft37i atpq:a 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 8jq ;j exj;a4+nmi )li(Drosophila melanogaster) have 8 chromosomes. How many c )e4a q;;jnlimij+8 jxhromosomes are in a fertilised oocyte of a fruit fly?

  When does the random orientation ob( aku a3mx:tfgwqg3x4/,7owvb 3s( pf homologous chromosome pairs occur?

The majority of the genes in the human genome h7 xf99y+lmqei * 8y.a2atp/y xa4mise ave already been mapped, meaning the exact locations of the genes 84y*as9p y2i9exme/t+x 7a.aq y mlfion 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 linked w;9z-7pxp)+ v khh9 0ae wpnqygenes?

  The diagram shows a karyogram of a brown male rat (Rattus noask cykoqlmbu9x,4 b;xy9j r4:45w )frvegicus). Which arrow is pointing to a pair of autosomes? 4yla9wk, xf ykx9q br54m;j o:sc4bu)

  Mendel observed that there are two possible variations o1 mfedemr b15/f 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 genotypes of the pa1bmd/e 1fer m5rents?

  The graph shows the frequency of birth weight of childregfh( m :ccao.6n born in London in 1991 ( ac6oh.mfg:c.

  Which of these traits is an example of continuous va2f)m- pax6np wduc4lh;l c63b1 t9lfkriation?

  Which row correctly describes diploid and haploid cel, 2jokviw+shlko,0y39h g la:ls in humans?

  The following table shows the diploid chromosome number y e 2pe olcs m/:o+x2lrf4-6qu3 vkykjit56j1of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused6g,4 ewnxl*0 vlvuy*nry. p+ t 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 with blood sg 0ehw8idqw0i 4g09b type A had a child with blood type O. What are the possible genotypes of the bio4b9gd0qgiw 0 wh s0ei8logical father?

  Which row shows the correct annotation of the alleles7d /wm8kw;jti;p pv-q for blood groups?

  Which of these statements are true for allelesr4 cwbqa4gs -l/q e*v9lsm1 y5?
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 malaria acr ,0zm4il ltz zq3sdc,1wa0i)50 mybdfoss the continent of Afr) imyc03md0t1sz qbazi,0z5l d4flw,ica.


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 numbex-7 wrl:9 (xjftdxjl)r of genes. Brown colour (B) is dominant to sandy colour (b) jjlxdf( w7-xr l9t: x)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 ge uqwptr6q 277ynes.

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

Sickle cell anaemia is caused by the allele0mib,rf0j; 4vg.bas c qjfh 73 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 showsd9 eqe(4quk e: a cross between a male cat that is homozygous for brown, long hairdqeq:( ee9 uk4 and a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the a/chbd5 n4ltt5a-nu 9 0y p:4 ;hghwawlllele for diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) is domina5lh0 a;44wpc5: dn-u twhhltg9 a/ nybnt 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 )- qykgzt;a95 e;bo ihhair (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, stio b g5ehqak-)z;;y9 traight-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 in 9: .hvqk3hd:z t7sipkheritance of the condition shown in the pedigree chart below? st: k hh i9vz37kp:d.q

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

  Which of these statements about genetic disorders is/are 9gp o e:rl,hb,*95*1wdx r so8 o-pgidetexv.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 2ndc cw7r(.jvtraits 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 the inheritance of the disorder shown in the pedir.nc7xen sqei +7s 6e9gree chart is X-linked recessive and not autoss7+i7.nr s 6necxeeq9omal recessive?

  Different species of living organisms have differwdpvlejm*7 *w 0yj1,;mh e7lp2ph*qhent numbers of genes characteristic to them. The table shows the estimated number of genes for five species. w02m*pe *7 yem*,;h7whp1vqph ljj dl
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, a6y m/9k)l /m89p6nz p jphoitincluding flower colour. If the pea plants Mendel was studying can only be white or py6 9tm/p8hpaz/ik o)n 6mp9ljurple and follow the rules of Mendelian genetics, which of these statements was correct?

  A biological male with hemophilia and a biological female wit*s4byoa1 70m lgus wn; 39nohdhout hemophilia have a daughter without hemophilia. What arewgo1s4loym0 n 97u nsb d;ah3* the possible genotypes of the daughter?

  A dihybrid cross was carried out between two sunflower plants (Helis 9ckfaubnw e3k:0 ov2 13lc9yanthus annuus) to see if the genes for seed number and seed shape are linked. The critical value forf9:v 1ane0wk2yu 9cb okc3s3l 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 a8k3mnsg1- fqh w,- frtype A and blood type B can have a child with blosr-f f8a1 w-ghk3m n,qod type O.

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

3.Explain the role of inheritance in genetic diseases.