A man and a woman have a daughter and a son. Their daughter has nrjw fn/o* 6i7pormal vision, but their son is colourblnf /wijrp67o* ind. Which one of these genotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a sol azr+r-3m q qz +-aj9k5jx.phmatic cell in a human male?

  There are two alleles for flower colour(4v rne9lkxk3 7vf bf8 in snapdragons. However, the result of a cross xf k rl 43(bvn8k7evf9between 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 fzhbmbryxg)82h 72ms .r e 90lto the correct definition?

  Which of these statements o -- uqgsbf 3*5rst0h1fi1fjq is a correct definition for a gene?

  The diagram shows a pair of homologous g8o v by1 :a:;2cnnzavchromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specificd q(db 213y-hrooch8 c trait, were crossed in an experiment. Which row shows the expected phc8hdy -( ho32q1ocrb denotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti allel-4 i3ddzq(rn he causes individual hairs to have a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who are (d4i nd-zqh3r 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 l2s9m0rt +33ctolq bw pea plants was either round or wrinkled. The results of an experimental cross yielded 315 offspring with roundo w923lqmcls + 0tbt3r 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 (4/ml+uw a9j18 j0 xkbdl bicf1Drosophila melanogaster) have 8 chromosomes. How many chromosomes are in a fertilised oocyte of a fflm1ldb x/9ua1jwk i084j +bcruit fly?

  When does the random orientation of homologous chromosome paing / 9e* zg, q-e(3n;, hfysenkx)zoixrs occur?

The majority of the genes in the human genome have already bc. , r 1s8,b5hwou q/idkhxskv5mc44h een mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows o.kv cs,h8 hwks5,1xo ucd/44irh5mbqne 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 genes?p acy;lkw9 -.+ bv)junj 3k-bj

  The diagram shows a karyogram of a brown male rat (Rattus norvegicus). Which arltf7rmo9.d/6a +cg cb row is pointin9m oca/rf6t.d7+b l gcg to a pair of autosomes?

  Mendel observed that there are two possiblu pp3uvu-f56 fe variations of flower colour in pea plants, purple and white. After a genetic cross, the r3 fv 6uu-ufp5patio 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 Loy ( unt-79hkcmndon in 1991. um -9(cky7 tnh

  Which of these traits is an example of cont.xh3 .uf43y*cxjfzf, dp5zjbjp1vj9 c8xt (sinuous variation?

  Which row correctly describes diploid and haploid cells in humano qdm6vo/ivw dqt:a/(q4 *i(ks?

  The following table shows the diploid chromosome number of a range ox;3yx u75px 5e0njd- rsknz)( fo* 2,qrqeg pyf species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive allele b)3hx ny :y6pz8ndf,q(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 typykgw2yhz 8s5i-1za/f e O. What are the possible genotypes of the/wy8if ghs zz- aky215 biological father?

  Which row shows the cory;axrjy-3 g(. 0hrm7lf5b )q7k b vmk(ytnr9n rect annotation of the alleles for blood groups?

  Which of these statements are true for allej fy:w l nw5n m.rzmhc7.ea-9)les?
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 ohfjke ,(j5mt 4f sickle cell anaemia and the spread of malaria acroske ,jj(5mth f4s the 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), furiga11ht g;h; u5ip- do colour is determined by a number of genes.1d iiuph1a; h5g ;o-gt Brown 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 betweemg )p.tp9 w 7hj/ ebktp6)uk,sn linked and unlinked genes.

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

Sickle cell anaemia is caused by the aoxwt z/(x)wuk :*;jn mllele 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 betweezbg jk4q 6e)0g67(yp5ehy9hgfuz-m g n a male cat that is homozygous for brown, long hair and a female )jgebg54f z (0em6 g7k-hh6yqz ug9ypcat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamond-shaped3hkun-p1 x 8fj seeds (D) is dominant over oval-shaped seeds (d) and the allele for 1 8-fujph3xnk 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), long hair (L) is do; psfb6 vm;j bx,v5+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 ad5sv b+o pvm;,f ;x6jbnd 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 condit t3/vgfmjv4,zi(2 frz ion shown in the pedigree chart below? /gzz4i3v2f rm vjft(,

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

  Which of these statements about genetic disorde)dy0z u8*ri d ;ss4ygl4eqbq;rs 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 polygenictosssj4:a 3r 2+iqqmi*-e ;qvj-n )zi traits 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 shdy1ohih 0k +b9own in the pedigree chart i+90 hhd b1ikyos X-linked recessive and not autosomal recessive?

  Different species of living o znz8vwll/d5s t0-z2brganisms have different numbers of genes characteristic to them. The table shows the estimateltz2b58 /z-0wn vl sdzd 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,+1njogtw3v*6ox( aih bw)ar,aj9v d- including flower colour. If the pea plants Mendel was studying can only be white or purple and follow the rules o-,ovta jg)w9 a6dn+3b(o1j *riv waxh f Mendelian genetics, which of these statements was correct?

  A biological male with hemophilia and a biological femau p;l2 -2 sblm2ii*,n*xb2cz;oo sq mule without hemophilia have a daughtmp ;2mi-uncs *o2b ;sx*ll u2,qbozi2er without hemophilia. What are the possible genotypes of the daughter?

  A dihybrid cross was carr7nx5p l+jb fq:* uptk-ied out between two sunflower plants (Helianthus annuus) to see if the genes for seed number and seed shape are linked. The critical value for the chi-squared test at the 0.05 significance level was 7.82. The calculated value for the chi-square5t:*uq- +7xblnf j kppd test was 10.05; what does this indicate?

1.Explain how parents with blood type A and b7 tuju4;e4g;hf 0mwva lood type B can have a child with blood typeug44vatj0h mfe;u 7w ; O.

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

3.Explain the role of inheritance in genetic diseases.