A man and a woman have a daughter ityf)6 u2v/d +y (weleberm.v)s9ha1and a son. Their daughter has normal vision, but their son is colourblind. Which one of these genotypes could be correct for the biological mothevrt )9mabvy(de uw )lfhye/+62 i.s1 er?

  Which diagram shows the sex chromosomes of a somatic cell lny1 :i4l51h;g6kkffci9 pp d in a human male?

  There are two alleles for flower colour ing)poj3/zhwh - snapdragons. However, the result of a cross between two heterozygous plants yielw/j 3opgh)h-zded offspring with three different observed phenotypes, red, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched txl;l:ms c del6wek. 3. sd3b1ho the correct definition?

  Which of these statements is a correct definitimw j0me8*,ujw on for a gene?

  The diagram shows a pair of homologous chromosomes. -plsm0xz+ +x l iu 9lz/()wnkx

How many loci are shown?

  Two individuals, heterozygous for a specific trait dk+uk7fr, :jt, were crossed in an experiment. Which row shows the expected phenou j:t+rk k7,fdtypic ratios of the offspring resulting from this cross?

  In some animals, the agouti allele causes individual hairs 7eh dzmmqm g9)owa 4pi7y(* b+to have a banded pattern. The non-agouti allele causes hairs +hmb mpoqg7)(7a w*yiz m94deto 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 o gzxu9s 1p pm8.su-r x02)aguw9q s ju8ycx:o/r wrinkled. The results of an experimental cross yielded 315 offspring with round seeds and 105 offsprgr9)zp81w u8 o9.x u0ax2q:gujps /-x mys ucsing 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 chromosomes. 7ioa 7a j-vr eu0:tqj1jcuu uzq*:) w1How many chromosomes are in a fertilised oocyte of 7rtu -o)zve ::jijj 1u qqu70ua w*1caa fruit fly?

  When does the random orientation of hly()z ueeon sfcip0xglp :mg37 ,9.+uomologous chromosome pairs occur?

The majority of the genes in the +43bz6jdur* u2hnsda*go45nt/nymdhuman genome have already been mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one representation of a homologous pair of chromosomes. nndo+ s*zm2nb /j5uhrgt3 u*y 4 4d6ad

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 gene g-r 7amtlr 27gi/p)qts?

  The diagram shows a karyogram a)c2x / p/uhmtof a brown male rat (Rattus norvegicus). Which arrow is pointing ut/amh) /cxp2 to a pair of autosomes?

  Mendel observed that there are tw 0,zwoa k3sa 73ihws-wo possible variations of flower colour in pea plants, purple and white. After a gz7sw3 aa,osk-3hw0 iwenetic 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 z7.3ihh i r(jfweight of children born in London in 19917 3ihj hifz.(r.

  Which of these traits is an example of conti lzmgt:b0a5 ;ruxfo68nuous variation?

  Which row correctly describes diploid andzzsc1he 1m)fy wytu-m a ar3ljk2445; haploid cells in humans?

  The following table shows the diploid chromt k37 av7z1keyosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive alles4 +mn)1l z9vo2noij sle (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. W5 m4tuo l33vxrhat are the possib53rv4l 3x utmole genotypes of the biological father?

  Which row shows the correct annotation of the alleles for blood griv0vfk d/9r*boups?

  Which of these statementskh,yrkn e0tt70 q8xk;s op8w6 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 incidence of sickle cell anaemia and5he2 xo4gmzcn m/ f-y, the spread of malaria across the continenzy2om- m,f5hg4n cx /et 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 determined pbu.9p07 +sffj + lqle/ bxq)tby a number of genes. Brown colour (B) l+0p bs lf pqu9x)tef7.+b/qjis 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 linked and unlinked09j* z* ku lqhu4 a8;k.wx63y cscunqv genes.

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

Sickle cell anaemia is caused zvu xak8.2 (nrby 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 cs p)ek )02raqmat that is homozygous for brown, long hair and a female cat that has black, shorsm ak2 ))eqp0rt hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the wf si:17/ ihpuallele for diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele wfiipu7/ h1:s 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)xck 1q - gqf+w54(nacu, 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 f+45 cug(fc1axw-kqnqemale 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 the pedigrb9i8 xn-(hs) jsn j2viee chart besx( 2 nvi jjhb)89-nislow?

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

  Which of these statements about genetix 82nhuqkz7p(x 3:sn)bz sl p8c 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 sq,vm02dc,foq9 z3 g rfhow 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 inher *iy2t v/pcc:xitance of the disorder shown in the pedigree chart is X-linked recessive and not autc:*cp/v ytxi 2osomal recessive?

  Different species of living organisms have different numbers of g i 6r:qqkzf wd.od/wb:-ed+/senes characteristic to them. The table shows the estimated number of genes f.d6/d +ifbkswz/:-q: qwe o rdor 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 co*+jryzlr 4-n elour. If the pea plants Mendel was studying can only be white or purple and follow the rules of Mendelian genetics, which of these zl*ej4nrr- +y statements was correct?

  A biological male with hemophilia and a biologicalw +8am: j1k o/e(lpm8tibdzk 7bc9l6vqlq *q6 female without hemophilia have a daughter without hemophilia. What are the possible genotypes ofo +8(qjb zl6ivd7* 9:6w/mc q1etlka8 qblk mp the daughter?

  A dihybrid cross was carried out between two sunflower plants (Helianthus an+prmq, 8pp hxmt*sno6 a5 15z.ngr6 bsnuus) to see if the genes for seed number and seed shape are linked. The critical value for the chi-squared test ap 6amsr,h8.*p t1+6s5 5nz gn pqomrxbt 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 blo7-s8 *usltboe od type A and blood type B can have a child with b b8e7s-ot lus*lood type O.

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

3.Explain the role of inheritance in genetic diseases.