A man and a woman have a daughter and a son. Their daughter ha o7:qn2hglv .ws normal vision, but their son is colourblind. Which one of these genotypes could be correct for thewq.vg nol27 h: biological mother?

  Which diagram shows the sex cf4hwpyt - yr*4p1x(ke mcx5v)hromosomes of a somatic cell in a human male?

  There are two alleles for 6n1lw*mgcvvo nn8 ) w:flower 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. Which is the mos vw wnnvc8m6 :)ng*1lot likely explanation for this observation?

  Which keyword is matched tnmo.imjyc8mcf+q(2l,i ; z m 8o the correct definition?

  Which of these statements is a correct def/fqkkflc8)a-e;-:,vw o jpwtinition for a gene?

  The diagram shows a pair of homologous chro:9 ijbv g;7tcimosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were croz7wl ty+/m5;ie*f lo ict: d8kec-c7xssed in an experiment. Whiz c7c-i olty8cxedwm7 :e kf ;lt+/i5*ch row shows the expected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti allele causes individual hairs bi34zfg lk:z, to have a banded pattern. The non-agouti allele causes hairs to be a:fb4g,3liz z k single colour. Individuals who are 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 plane z8s3xw( bk:yts was either round or wrinkled. The results of an expe:k8ebx szw3( yrimental 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 chromosomes hq5oa-9+ ay3nijdkm, . How many chnd3j im+ ya9kh5q ao,-romosomes are in a fertilised oocyte of a fruit fly?

  When does the random orientation of homologous chromosome pai4p awxq+v6cm9 rs occur?

The majority of the genes in the human genome have already been mapped, meaningtknbqq r 30d(/ the exact locations of the genes o 3t0bdr(/knqq n 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 definitio60,iel+pcy *c c v,7t:o:gqhsuyonq) n of linked genes?

  The diagram shows a karyogram of a brown male rat (Rattus norvegicus). Which ap q1d b9e(7j ax 6t5jj3do6rjkrrow is pointing to 6brjdj qp 7 t3j(o5d9xek6a1ja pair of autosomes?

  Mendel observed that there are tw7t0e gphi pw;*/16 t7hds *vlragbwq+o 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 were the genotypes of tvw6*7p q+* biwa7gst gh0/dtl;1hr p ehe parents?

  The graph shows the frequency of birth weighfd + 6 5vs9hpk 2yz77qad5jkoyt of children born in London in 1991 k+ od9apkj hfq276dy557 yzsv.

  Which of these traits is an example of continuous variriqhp 6 y z7x4q5+md+pation?

  Which row correctly describes diploid n6;el,r+o7qhh7z gcs i prz,6and haploid cells in humans?

  The following table shows the diploid chrc c+ nw1lzl3kgl;0u. gz-e 6naomosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a reccc.q7hsc1pp( w qy/(p : luk,dessive 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 wir:.foi ef ::qz,goh4vth blood type A had a child with blood type O. What are the possible genotypes of the biolfo ,e .vzo:g:hf :qir4ogical father?

  Which row shows the correct annotation of the alleles for blood groups?3bpi4 1m npf.j

  Which of these statements are true for allelesypzt( ; 3k 9/cjcqf3fq?
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 the spread of malbiltj3 +f7na;8 xzn tl, - te*itvbe74aria across the continent of Afrj37;lxaf tiev8bn e* t-+t4lni,zbt7ica.


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 pryq 6wpnyel8*p+4,oc ts g3wa*zewalskii), fur colour is determined by a number of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) colour (P) is dominant to one tone (p). wl+pqwt,6*n4cao gy*es38 p y


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 genef 2(j trx -f2y2duyh61fq+ n1t,yplh ts.

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

Sickle cell anaemia is caused by t2qy0q6 *jc,v pcmtk/n 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 ma vkf.u2 ev0 .v5v ybx5v0oc6nfle cat that is homozygous for brown, long hair and a female cat that has blacvnkv0y5cue xvv0fv. fb52o .6k, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officx1r1a dppgn245 ic 3huinale), the allele for diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for h x3di1ra ug5nc14pp2 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 porc h/.ry(qi6hptiyxam k4f3,6 f qo6pk)ellus), long hair (L) 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 out on the offspp6h q6fk qap3thkx , mor/.i(yy6 4i)fring.



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 o4jxq 7xhwx )s* b-bntn,xe )i 95crz0ff the condition shown in the pedigree chart xj5 0,b9 *-xrtb ife7 xsxnw))nhz4qcbelow?

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

  Which of these statem4k owx ))m: 5cneiwa+vents about 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 trai(9oo*myz 8 -n 0cqjfghts 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 thevljz -7md8fb1 disorder shown in the pedigree chart is X-linked recessive and not autosomal recessivebv-f 1 dj87zlm?

  Different species of living organisms have. ft:e;w1p8uu g4b foq different numbers of genes characteristic to them. The table wuug :1tf;48fe .qbposhows 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 pea plants, including flower c ppjmr 8(druh:3*c2 up9e-hrlux5t 8rolour. If the pea plarmjc d*(eh5rp:t2pulxr- u8 ur 8hp93nts Mendel was studying can only be white or purple and follow the rules of Mendelian genetics, which of these statements was correct?

  A biological male with hemophilia and a biologilv8 3 viz25enacal female without hemophilia have a daughter without hemophilia. What are the possible genotypes of the daughtera3z v8e lniv25?

  A dihybrid cross was carried out between twoq6xbf6a fb*4d 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 thbf *dq xb64fa6e chi-squared test was 10.05; what does this indicate?

1.Explain how parents with blood type A and blood type B can have a chi08-ha*l8 yvy d lw,bhle2oi 4d(nl1dqld with blood yl4d ad,lnyqloh bwvl -8*02hide (81type O.

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

3.Explain the role of inheritance in genetic diseases.