A man and a woman have a daughter and a son. Thptb0go/b .e1*jh i,s oeir daughter has normal vision, but their son is colourblind. Which one of thest eh,/.ibobg *s1opj0 e genotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomesgy8d pj ad4a o.(2;aipux)tcwq y(9n6 of a somatic cell in a human male?

  There are two alleles for flowa;jnran lcbnk 4fi+v, )1o0r-er colour in snapdragons. However, the result of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red, white and pink flowers.4o,jlnk0cn- 1) nfvab+ria r; Which is the most likely explanation for this observation?

  Which keyword is matched to the corrm5o7drz4l b;e ect definition?

  Which of these statements is a correct definition fo/dmtz9 fvk()j r a gene?

  The diagram shows a pair of homologous chromosomes.q6ca-spiqqdb q:s9 8x:rp1/ a

How many loci are shown?

  Two individuals, heterozya;xua3u9zh opg41 l4mib,/ cd gous for a specific trait, were crossed in an experiment. Which row shows the expected phenotypic ratios of the offspring resulting from this c9 a3i uclx;bog4z ,a1pm d4u/hross?

  In some animals, the agouti allele causes individual hairs to heauzk6f j;6 l5fa+pd 7ave a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who are heterozygous hae f6jk p;6f5dlza+ 7uave 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 y)-yjdg 3oc5b:rg hi/shape in individual pea plants was either round or wrinkled. The results of an experimeyo53gbi /d r:g)jhc-yntal 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 meeq /4n4zbcq rg..;mmyjk w 7f /+8.) gyzzkvualanogaster) have 8 chromosomes. How many chromosomes are in a fertilised oocyte of a fruit flekfmgq mj+ .a4/g4;nz/yy ubkq .)rw.8zz cv7y?

  When does the random oried rje;u80xzzw)m.- (fkmyve3os 2o a1ntation of homologous chromosome pairs occur?

The majority of the genes inb qu ,-orjme4a+ u+bp2h,c9 hg the human genome have already been mapped, meaning the exact locations of the genes ucq9 g+, b,-heboup 4m+hr2 ajon 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 definition of linked genes?9*7rtu.m rmvm

  The diagram shows a 3sx5q amwy (8bb6:g saa3 h:vkkaryogram of a brown male rat (Rattus norvegicus). Which arrow is pointing tow:8s aah33:m x(bk6gya5bv q s a pair of autosomes?

  Mendel observed that there ao ow45n wsf05tre two possible variations of flower colour in pea plants, purple and white. After a genetic cross, the ratio of plants with purple flowers to white flowers is 1:1. What wfw 5o0stn4o 5were the genotypes of the parents?

  The graph shows the frequency of bir5m +koopjg 0 2oqt/(c6nav /sah6zr)ith weight of children born in London in 1991/ormpgs+hz5qti6 co2/0an a )j6 (o vk.

  Which of these traits is an example of conyzeai; rb u-92tinuous variation?

  Which row correctly describes diploid and haploid cells in huaz 5v4v,w6w 9uvzhtf8mans?

  The following table shows the diploie(u mbzw-/j 8j5obog, .8 hcv1kns:l6lgzk/cd chromosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is causeyo *w1ev)pb3 zd 6x0ddd by 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 witpl42fr p q+kp0h blood type A had a child with blood type O. What are the possible genotypes of th lkpp402pf+ qre biological father?

  Which row shows the correct annotation of the alleles 6deha(wk bseh:0 6k6c for blood groups?

  Which of these statements aresy1cwvcdcq-t; d5,-h 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 ana2u gxq :hc0u5r58qztu8 jeesd8)cr(femia and the spread of malaria across the continent of Afr(5h8td5q r0e2)frs ezqcuxc u 8j:g 8uica.


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 determ wfecb-(*+zgd0+t cr*q sfsi+ined by a number of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) colour (P) is +-*s dwqtg0c+i(cbf+zf*ser 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 linketi c8qy n2n i 1n1rilxt8adr3868;famd and unlinked genes.

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

Sickle cell anaemia is caused by td g, puw3e/kk p73sqk* /hzar,he 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 maxc) y dlfx14h5le cat that is homozygous for brown, long hair and a female cat that h)c1f4lxdh x 5yas black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for dxc,h )f0p)fp:znfxi8qe-6ha53vjow iamond-shaped seeds (D) is dominant over oval-shaped seeds (d)5:fnao, -pfix3ec) 8 ) jpxqh6vzwh0f and the allele 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), lon)5*drbr /cswc g hair (L) is dominant to short hair (l), and curly hair (C) is dominant to straight hair (c). A test cross was carried out betc*drcr w)/sb 5ween 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 condition6zq- t+ue*z uf shown in the pedigree chart belq +t*u6zu-e zfow?

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

  Which of these statements about genetic disnj;2 rv vc8c-.p+tpswwvn h 1;orders 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 al e f;du6l3g6m 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 th1 n2pzz1p 1w czj/3/vns+ 0onpl/ xpcme pedigree chart is X-linked recessive and not autosomal recessiv s +pnwp/ /1opvc/zz2n3xj0cp ln 11zme?

  Different species of living organisms have differo*zk4x:/ gusuent numbers of genes characteristic to them. The table shows the estimated number of genes :uz s xuk4*og/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 co b vktzmxg7l:;.rc-6elour. If the pea plants Mendel was studying can only be white or purple and follow the rulem-;.xg:zc 6lb vetr k7s of Mendelian genetics, which of these statements was correct?

  A biological male with hemophiliiqcu5x :x:(jqttf o9 ,a and a biological female without hemophilia have a daught:x5:u 9q,jtfxi(qo cter without hemophilia. What are the possible genotypes of the daughter?

  A dihybrid cross was carried out between two sunflower plants (Helib;j8a gukpnkep c1d))mm) k.8anthus 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 signifid .;mk)pmpk8)e 1b 8k)unagc jcance 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 ab4 pwq18v1 *aj xk8iiy;cb6fznd blood type B can have a child with blood type O. ba4piv61x wzc;yb k8q8 f*ij1

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

3.Explain the role of inheritance in genetic diseases.