A man and a woman have a daughter and a son. Their daughter has nor(fs7s , /rj1zp,hyn )sno uc5nk0md4kmal vision, but th1cu5jh fk spm7y),s 0o4kd(r,nszn/neir son is colourblind. Which one of these genotypes could be correct for the biological mother?

  Which diagram shows the / m2zr()bsi b /l9onjbtc-ep 5sex chromosomes of a somatic cell in a human male?

  There are two alleles for flsq(fd.x sk te. xf+83fower colour in snapdragons. However, the result of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red, white and q+d8 k..fex fss(tfx3 pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to the corred(g4d *be4win o;uzubo e61,bct definition?

  Which of these statements is a corre2(9rg fvjljg3 *uv3l +j k4mknct definition for a gene?

  The diagram shows a pair of homologous chromosomes.zeby4hn-ez* +m-db 7x

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were crossed in an eue 6. ,tjn5 e,jexdjy0xperiment. Which row sho uet5je,xy.n 6dje,j0 ws the expected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti allele causes individual hairs to have a jmwq*l04 bkk;banded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who arek 0k* 4bwmq;jl 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 6r/k :apuw:9.wn i d-qxwsk2qround or wrinklqwr/- i :6wa9n2qkp s xukw.:ded. 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 (Dro9git 84c qgre2sophila melanogaster) have 8 chromosomes. How many chromosomes are in a fertie8 q rcg942gitlised oocyte of a fruit fly?

  When does the random orientation of homologous chromosom s5si*ayer +qisruwks.8:( c 3e pairs occur?

The majority of the genes in the human genome have already been mapped, meaningwwvul,,0ptgn8z cyt c 5.;a3 z the exact locations of the genes on chromosomes are known. The diagram below shows5v; wy.ntp 3w,0c ,ltca8guzz 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 lw1jmk l6 l3jk9inked genes?

  The diagram shows a karyogram of a brown male rat (Rattus norn.o.k4fh +g 0bdfnm4 rvegicus). Which arrow is pointing to a pair of a0f. ghr+d4m n4onfk.butosomes?

  Mendel observed that there are two possible variations of flower y0 ,ag8xr a4f8waty/mcolour in pea plants, purple and white. After a genetic / m8y 4ytrwx,8aaf0agcross, the ratio of plants with purple flowers to white flowers is 1:1. What were the genotypes of the parents?

  The graph shows the f :*e l dt*:e9f6o:kuhruy fz5y 2.fsverequency of birth weight of children born in London in 1991tek d2vefy:eusr6fu:*y .59 ozf* :hl.

  Which of these traits is an example of b*ha c1s.4cpbh0ezc xbfb o79 gq:q65continuous variation?

  Which row correctly describes diploid an()n4) af:h;z cjaen-v uh i;qzd haploid cells in humans?

  The following table shows the diploid chromosome number of a range of specdtr+ipwy*4 zsre -4w/ies.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive allele (*yptn n pris*()ydn* 7s+j eo4Hb$^S$). 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 0rxmr *g ) 1blt.jwbn+are the possible genotypes of the b*01+nj rmxb ) gbt.rwliological father?

  Which row shows the correct annotation of the allelesn. 672mzpkk g+s,urqh for blood groups?

  Which of these statements are true for awy r ,d641o i78 besolen4;lnslleles?
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 crvf1)qmulf()-i r u 5 hjyvb9 4pho;(vell anaemia and the spread of malaria across thvuhqrv 5(juh( ovl 49f-)) irfy;1bpme 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), fu,/wg3hepkr - br colour is determined by a number of genes. Brown colour (B) is dominant to sandy colour (b) an ,wph-ekg3b/r d 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 genes. vkmlr*4pf:a: y 9lij4

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

Sickle cell anaemia uzx647-zyg 9h6 ih zt:ufhty 3r:tx/vis caused by 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 betweenuztacj82 e-9v:e1pyn a male cat that is homozygous for brown, long - nc2tz:e8peyju9 va1hair and a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamond-s (powo9uq*s9xhaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) ioxo p*9qu(w s9s 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 dominajwgghl. jc ad u515/4)nr 0k0q -flkgqnt to short hair (l), and curly hair (C) is dominant to q.g 55du l1ln04jfw0cakh-jg /)qkrg 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 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 pedigkigun nv8aw+c6*eao1(r, 3 ksree chart (68,*auas en 3 ckr n+wivok1gbelow?

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

  Which of these statements atenct si;r9c57 t3k2gbout 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 show a n4igpiieww:jaf+,*m:2 : ogb g ormal 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 dism ew(v+)ba jg swc25st8bp.:yorder shown in the pedigree chart is X-linked recesw:e)yjs5mbvc ws.g a8 b2t(p+sive and not autosomal recessive?

  Different species of living organisms have different numbers of genes charac+d o * 5w6jmq 3ufzs/fu:9sqqjr/s0dl teristic to them. The table shows the estimated number of genes for five speciesl:udr96/*j dz uq3 j s w+ffo05/qsqsm.
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, inclmje0 t m(7 q6jcyu*7xxp+dl6g x.mrk0uding flower colour. If the pea plants Mendel was studying can only be white or purple and follow the rules of Mendelian genetics, which of these statements was corr67 +*mx 0cgpx.k0yd mu j(6qltej7xmrect?

  A biological male with he6))aabc agh7/r7nxsvmophilia and a biological female without hemophilia have a daughter without hemophilia. Wha a/ahc6v b)a rx7g)s7nt are the possible genotypes of the daughter?

  A dihybrid cross was cari m.e jpe86 ,mxgl8v/bried out between two sunflower plants (Helianthus annuus) to see if the genes for seed number and seed shape are linked. The critical value ve . lpg68xj, i/emb8mfor 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 type A and blood type jz ,sos6f5 (yklr4k-9mnn1iwk2o t1zB can have a child with blood type 6z l24-1t1royo5jm(fk9kkn ns,sziw O.

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

3.Explain the role of inheritance in genetic diseases.