A man and a woman have a daughter ain 67p j-cnnj2nd a son. Their daughter has normal vision, but their son is colourblind. Which one of these genotypes could be correct for the biological mother? j7n2ijpn-cn6

  Which diagram shows the sex chromosomes of a somatic cji:pp .myc 15dell in a human male?

  There are two alleles for flower colour in snm0gjqjkt lhwy 584 *f5apdragons. However, the result of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red, white and pink flowers. Which is the most likely explanation for *h8ywmtj 55q0kjfg 4l this observation?

  Which keyword is matched to the lt; z g;9+iwqpe akhe; cum08;correct definition?

  Which of these statements is a correct definition for a c6qj6dmpv*d9 b0 z+ )l lkcj.xgene?

  The diagram shows a pair o32bg8pizp4 v/e pt9mxf homologous chromosomes.

How many loci are shown?

  Two individuals, heter zubnfl:m25:sb2u9 iaozygous for a specific trait, were crossed in an experiment. Which row shows the expected phenotypic ratios of t29:uam:f2 sbulz b5 inhe offspring resulting from this cross?

  In some animals, the agouti allele causes individual hairs to have a 0 ip9njfhm2r h2l0.ljbanded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who are heterozygous hn0jfil20l9m2 jh.p rhave 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 p,img8b ht t; 4t6,lhbxb mb,n. 0p4etfea plants was either round or wrinkled. The results of an experimental cross yiet.ttbb n4b 6; g,hp,,4imh0bmxet8 fllded 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 chromosomes. Howd:h-0q7 ) opwehqe;z p many chromosomes are in a fertilised oocytehd7qpw;h-o) z0p :e qe of a fruit fly?

  When does the random orientation of homologon/) jyl wuq9x x4q6mr;5 tkjk/us chromosome pairs occur?

The majority of the genes in the huerqazek/d9 7. man genome have already been mapped, meaning thez/e 79ka rd.qe exact locations of the genes on 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 linke)oc,8 5cii. vcng gsy-d genes?

  The diagram shows a karyogram of a brown male rat (Rattus norveg 9xd97*uvrieyicus). Which arrow is pointing to a pair of autosomes? u yx9e*v7rid9

  Mendel observed that there are two possible variati5pb3 odz (die0ons 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. i (obzde350p dWhat were the genotypes of the parents?

  The graph shows the frequency of birth weight of child sygjsavpo tf4, dqma9/10 9,jren born in London in 1991. /g 4ts,vjqsf 0ma1p, j y99ado

  Which of these traits is an example of continuous variay0 :xnj3np7yc a,q)oq tion?

  Which row correctly describes diploid and hat :p;//wa ap9gpgvk; aploid cells in humans?

  The following table shows the diploid chromosome nuxjb *8-7e uuk4x,:kla lvs;qtmber of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive alle5h7t/:gz 5a w yfimd ie)2wzu6le (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 typj2fjz 6cl:/o ry/bk 3ig9(afqe O. What are the possible genotypes of the biological fb/g j:z(3 9fq6ckiral yfo 2/jather?

  Which row shows the correct a(m1z2 5qji w)r cj3l0s*venp tnnotation of the alleles for blood groups?

  Which of these statemen9hq8su8)m 7kqbhw( w fq*y;xwts 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 and th khvdj ;73ziaip 4 p19qusad+:e spread of malaria across the continent of Africa.vzuihad p7+43p a:9qs1k d; ji


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 determinedo, p5ip3z nju) by a number of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) colour (P) is dom znj)5 opui3,pinant 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 vx 7,c9adz-q blinked and unlinked genes.

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

Sickle cell anaemia is caused by the allele k.f + *ns8qfl)dgij,m 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 cat that izc.megxxv 5( * (nad7v l*n)bqj0io6 ks homozygous for brown, long hair and a female ccvk0xi )*.oda(n(jv5 m n7e xz b*g6lqat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the alle u5et4lx 1o;hsle for diamond-shaped seeds (D) is dominanuex 1o ls5;t4ht over oval-shaped seeds (d) 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), long hair (sc;*z)g4 9 anyknso0aL) 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 female short, straight-haired guinea pigs and a chi-squared test (χ2) was carried outsosyza*0nn)4 ;9 cagk 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 o wjsxk2 (a1;tshown in the pedigree chart below?( t2w;1xjkso a

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

  Which of these statements about genetic disorders isw1y4435j oi rsih*lm q,b* egd/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 s/u b8,mbq e(sbcd wv.)k6.v mmhow 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 shown in the pedigree chartubpt4f1afz c3s :hs1/ v -eatd71qnv 2 is X-linked recessive and not autosomal recessive? 4f hfszb:at/eq21-d3 napt 7sc11 uv v

  Different species of living organisms have different numbers of genes 4 fdorimc3z4+yt0-g8hj* elccharacteristic cl44ho *-fdgy 3jtricm8+z 0eto them. The table 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 characteristics5bdv 255gq hyz of pea plants, including 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 statementhq2b5 v5yg dz5s was correct?

  A biological male with hemophilia and a biological female withoqqf 9q/ w*7 )au -lga,gmom;tbut hemophilia have a daughter without hemophilia. What are the possible genotypeq7/*m m goqwul9)q-b,fga ;ats of the daughter?

  A dihybrid cross was carried out b hz8u 62hmo gaw,yd/seqk42o*etween two sunflower plants (Helianthus annuus) to see if the genes for seed number and seed shape are linked. The critical value for the chi-4 /mo8k, o6hse2d*wh ugq2 ayzsquared 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 bloo4nv(wt4r y *:/fptswzd type B can have a child with bws / zwfpv(4trn 4y*:tlood type O.

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

3.Explain the role of inheritance in genetic diseases.