A man and a woman have a daughter and a son. Their daughter has norm+7n j w/1zqemmal vision, but their son is colourblind. Which one of these genotypes coulz/mm1 q 7we+jnd be correct for the biological mother?

  Which diagram shows the sex chromo* 3elzsgz7zkfv i :,*9uglu8rsomes of a somatic cell in a human male?

  There are two alleles for flower colour in snapdragons. Hol)t ou (0nv vwdq+*o(fx-fq v6wever, the result of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red, white and pink flowers. Which is the most likely explanvvlq6x o(t 0u+f(dw*q- f)o vnation for this observation?

  Which keyword is matched to the co.2b)z 7k 9nidzgsbgs3rrect definition?

  Which of these statements is a correct definition for 8;iy)dfn g2ys+ c n;a+tdle0 tg6 n,xxa gene?

  The diagram shows a pair of homologous b*v+ r5sold 9hhdg5-bchromosomes.

How many loci are shown?

  Two individuals, heterozygous 5sq0x3uqkv;-ctv t4w :* m.kerr. tqtfor a specific trait, were crossed in an experiment. Which row shows the expected q *r c;mtxurt3t 5k 4.t0v qek:s.-wqvphenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti allele cause6f00hg)od hq ds individual hairs to have a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who are heterozygous have hai0 hd) d0hgo6qfrs 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 roundc/u( .qkklw w3 or wrinkled. The results of an experimental crossu /kwwlkq .c3( yielded 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 (Drosophila melanogaster) have 8 ;s vn8v. np-.0aprvwd chromosomes. How many chromosomes are in a fertilised oocywr8.-;vapp . 0dsvvnn te of a fruit fly?

  When does the random orientation of homologous p1tkq5e; ini9*w 9n/anu id 8bchromosome pairs occur?

The majority of the genes in the human 7i2vpo6;i9p qz 5srzo g5)xkzgenome have already been mapped, meaning the exact locations of th9)sp2zr5 v;q75zzogki xpoi 6 e 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 defing+g6h )ityd2 yition of linked genes?

  The diagram shows a karyogram of a brown male rat (Ra5io73bh d 7y3swbcp :ekci b92ttus norvegicus). Which arr2ebboc7d3hwb93 ycpii:s7k5 ow is pointing to a pair of autosomes?

  Mendel observed that there are ti l)7+ eaeo+2 (bqqucmwo possible variations of flower colour in pea plants, purple and white. After a genetic cross, the ratio of plants with purple floq+l2u7(i mq)co +ea ebwers to white flowers is 1:1. What were the genotypes of the parents?

  The graph shows the frequency of birth weight b.vcflz 0jq )d*e,vxb6s965bva3oes of children born in London in 1991c9avbf63l eo6,zvvs db. s b0jxeq5 )*.

  Which of these traits is an example of co2 1.bsg ww0zbpmmw+7je6l,m/i:4hy (vszk tsntinuous variation?

  Which row correctly describes diploid and haploid tajx- y46. n.s7sslfvcells in humans?

  The following table shows the diploid chromosome numbe; +a /msk1eywltp ar30r of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused tfryzv1) d) 5sby 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 type A had a child with blood type O. What are 4 qsx4 ;qh:vrt b/uxe.the4./txerux4 q; bhq :sv possible genotypes of the biological father?

  Which row shows the correct annotation ofv eo-l nop6*:p the alleles for blood groups?

  Which of these statements are -ilmf 1*gt/cz 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 incidence of sickle cec vx31khlyx*q8:lpdn3/jd8x ll anaemia and the spread of malaria across thec8qx3 dx 1:k*8yl/ phldx v3nj continent 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 przewalskii), fur colour is deteyfkzic9 wpbol l;t5,ci97 7m( rmined by a number of genes. Brown colour (B) is dominant to sandy collf(7om tiiz;y9kpc lw7,9bc 5our (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 linked and kk u s*y rx6 van++o9il1x*-xuunlinked genes.

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

Sickle cell anaemia is caused by the allele Hbf h9t nnxtwd7 zx05+(s$^S$ . 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 h qat5i)fzjx1( omozygous for brown, long hair and a female cat that h(q t1)z5 jxfaias black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamond-shapeyafgbvg npzj602 6+b9 d seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) is dominant over shoz6 yb062j n 9apg+gbvfrt 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 porcellgg98 acdkde:-0pm,ft us), 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 betwe m9gdtfe :pdck8a-g0 ,en male heterozygous long, curly-haired guinea 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 inh0 ten(6to6:u orj a* syy;k:qleritance of the condition shown in the pedigree chart beln 6qer0oystt ;j( l:u6ka*y: oow?

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

  Which of these statemxcl31zmcyi) e-*d5 qvents 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 showq -v6vd mzs3rj6:b:wg 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 pedimxu q 3x3(l-sdqi*(i ngree chart is X-linked recessive andq*s 3 (3mild i-(xnqxu not autosomal recessive?

  Different species of livi6 sxucu m3+dklz; .wz(ng organisms have different numbers of genes characteristic to tl z szc.m; xu3kdw(6u+hem. 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, including flower colour.sf(fl+0 vetf h+a (xf) If the pea plants Mendel was studying can only be white or purple and follow the rvef0 +ffsx (fthl) a(+ules of Mendelian genetics, which of these statements was correct?

  A biological male with hemophilia and a biological female without hemophilia ha7 wf,ggpitgz /eu /2lvgg/( ;tarl4/pve a daughter without hemophilia. What are the possible genotypes og4fpui2g twv7,/gllp/ g a/e (rg /;ztf the daughter?

  A dihybrid cross was carried out between two sunflower plants (Helianthu 9s;v3 xbu7clob mv64zs annuus) to see if the genes for seed number and seed shape are linked. The critical value for the chi sbo469l 3cm ;vbuz7vx-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 have a chil57t2j;v1+ zwonjob ggd with blood to+g;n1w gj752jvzto b ype O.

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

3.Explain the role of inheritance in genetic diseases.