A man and a woman hallvwp:u09n r:ve a daughter and a son. Their daughter has normal vision, but their son is colourblind. Which one ovw0r:nl: 9lpuf these genotypes could be correct for the biological mother?

  Which diagram shows the sex chjs w yh+eeg6/de42)c kromosomes of a somatic cell in a human male?

  There are two alleles for flower colour in snapdragons. However, the 9)fivn,0rfc cbd h(o4 result of a cross between two heterozygous plants yielded off (9 ih4)vbo, d0fccnrfspring with three different observed phenotypes, red, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matcrkz 8(of1j(c)ynu vj 7hed to the correct definition?

  Which of these statements is a correi;4. (q(tzyzaz 7 un3jp2n nbhct definition for a gene?

  The diagram shows a pair o m mb br09s c5:dhdczhae3r/5(f homologous chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were crossed in an experi53 xq*x/ie bqtpqv8 l3ment. Which row shows the expected phenotypicqxlt8ex v/b*pq3q 53i ratios of the offspring resulting from this cross?

  In some animals, the agouti allele causes individual hairs to have a ba*w72e*r0nd5nad lt: qd ;i8c bwh*ktssn(bp:nded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who are heterozygous have hairs with a banded pattep(r :q0s7ts 5lnwh d:t*iea2b8;*kdnbc * wdn rn.

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 roe x*yxk503v bdund orke 3xyx0*v5d b wrinkled. The results of an experimental cross 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 chef 1xcb, om:/hromosomes. How many chromosome 1/xe:cfobhm, s are in a fertilised oocyte of a fruit fly?

  When does the random orientation of homologous chr6 3 s1 30hzqgogms/w0moifuyd:b40 qw.w vjy 5omosome pairs occur?

The majority of the genes in the human genome have already been mappe( ;s3 :g/bi66+dbrwsq02vashpez zl td-9nevd, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one representation of a homologous pair of chromosomesvphze: dzbb/ 6s(+3r s-vl 90g di naqetws26;.

1.Define locus.

2.Identify the number of loci shown in the diagram.

3.Distinguish between gene, allele, and locus.

  Which is the correct ,qsucfhfkh 5/k( 9 bq2definition of linked genes?

  The diagram shows a karyogram of a brown male rat (Rattus ny5v0w0p wbjsy8 -n9 f2wl roi0orvegicus). Which arrow is pointing to a0v 0r i nw5-bsy9w2opy0f8ljw pair of autosomes?

  Mendel observed that there are two possible variations of flower colj1+z rgn o v,7-su5gjxour in pea plants, purple and white. After a genetic cross, the ratio of plants sng7oxr,j zu-1+jg5v 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 Ly:;acnz 9iiw t+dlrbw(p g- ho7.) -ozondon in 1991.woozc n9p-(i;bizw ly+ghd.7 : ra-t )

  Which of these traits is an example oyzx zh.5 v 95mwkxc(/bf continuous variation?

  Which row correctly describes :*z4 ynjh7 sscdiploid and haploid cells in humans?

  The following table shows the dv( k/k.x*lk vdiploid chromosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a 73ixo/.+duulp7 tn9 tdliw 0 krecessive 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 blooda+ bs7ux6k.urxdrfh78 7b 4s z type A had a child with blood type O. What are the possible genotypes of theu68ufhx dbr r7a z4s+bxs7. 7k biological father?

  Which row shows the correct annotationx43)4aaee zmg of the alleles for blood groups?

  Which of these statements are true forbnn3sna 9i m;) 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 sictnaqrwx28wzug-rf 7 52q;k o 4kle cell anaemia and the spread of malaria across the continent of ;q f27wtzq4r nu gxr-k2 woa85Africa.


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 detex 0o:;edf wz+jrmined by a number of genes. Brown colour (B) o+;dzwef0:j xis 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 unlinked g yq)xpv*wvsd5/l k(2tenes.

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

Sickle cell anaemia is caused by the allele Hbrsotiu )e2o+1$^S$ . 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 tw d*m2qb1a )ptz/2h ho ib*jl4hat is homozygous for brown, long hair and a female cat that tba* lhz41jd2phb2) /qi wo* mhas black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allt6b/ wut1 +qrmele for diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long 6ru+tbq/ m 1twseeds (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 dominaqgy3 v 1-qhf1lnt 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, straight-haired guinea pigs and qgylf31qvh - 1a 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 rt*ugcdyg/s 0c28 jesn( , p+i6*qpva in the pedigree chart bel*u (2 8p +cqt,ica0ns*v gsprdy/eg j6ow?

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

  Which of these statements about genetic disorders is/areg x *1jv;sedz- 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 distributia04oq i cj*)ura0h.o hon.

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 thj/x fo820 yi3rat b-pxgvgl++e pedigree chart is X-lina+y8b0 tlopx/2f igr v3j xg-+ked recessive and not autosomal recessive?

  Different species of living organisms have different numbers ofj1a )enj.-6;jrb1ao h*djwsn tp, ,gi genes characteristic to them. The table ji.p- sjnjdh)aoewj tr1ba*g6; n,1,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 pe s82y8dsk w;hfdlr(37he5tf wa plants, including flower colour. If the pea plants Mendel was studying can only be white or purple and follow d(2 swhf;85wyhd7slfe3k 8r tthe rules of Mendelian genetics, which of these statements was correct?

  A biological male with hemophilia and a biologicalwvdf n a8x3;(o female without hemophilia have a daughter without hemo; o(dv83waxfnphilia. What are the possible genotypes of the daughter?

  A dihybrid cross was carried out between 3 jio*z;m-w we tbi4,utwo 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-squared test was 10.05; what does this indicate?4iowzi,et jwum- *b3;

1.Explain how parents with blood type A and blood type py6ikj4st7s f442 6tjrtrk8l2a 8l i rB can have a child with blo7 k2 yj s66rtafttrl48 2 si84jikr4plod type O.

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

3.Explain the role of inheritance in genetic diseases.