A man and a woman have a daughter and a son. Thei 9ga8fech:gc; r daughter has normal vision, but their son is colourblind. Which one of these genotypes could be correct for the biological mot:aehc;cg8 gf9her?

  Which diagram shows the s.oap;2b(m2+b5fhw m ejyo b- mex chromosomes of a somatic cell in a human male?

  There are two alleles for flower colour in snapdragons. c 1n;k4nfbcbf b md-/-w h(*ooHowever, the result of a cross between two heterozygous plants yielded offspring with three dihf b f1nc;b mn( *o-b4-/wocdkfferent observed phenotypes, red, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to 6), sbcrp*ip,k3tk ,jl;esxrq 0vk8 j the correct definition?

  Which of these statements is a correct definition for a gevme2x dr 1o m9e*7 3svipz,:lhne?

  The diagram shows a pair of homologous chkzq u4er mf7:9romosomes.

How many loci are shown?

  Two individuals, heterozygous for a s ),qvkx -,rur.t0wkm upecific trait, were crossed in an experiment. Which row shows the expected phenotypic ratios of the offspring resultk0rk) ,rw,m -xuuv q.ting from this cross?

  In some animals, the agouti allele causes individual hairmr ) qp2u3mqi 8u:4vwbs to have a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who )34q prm8ibmq:v w uu2are 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 plant e0;e8wdke9vemyz68z pdd4, os was either round or wrinkled. The results of an experimental cross yielded 315 offspring with round seeds and 105 owddop;e ez8e6 e0 ,k 49dmvz8yffspring 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. How many h1pz w sp770fcch1hpf 70cwz7psromosomes are in a fertilised oocyte of a fruit fly?

  When does the random orientation of homologous chromosome pafaq k)l146fg)w2 bnamzdps4;m*q s/l irs occur?

The majority of the genes in the human genome have already been mapped0ycdtit85e kt* -rp/mj3 u)mx, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one representation of a homologous pai jk5ytix/pcurtm)3-*t d8m e0r 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 ge3v n9y6,xqp+b z-i*y:r bnaeync 6f) gnes?

  The diagram shows a karyogram of a brown male rat (Rattus norvegicus). z05jsp ;s.ik xWhich arrow is pointing to a pair of autoso0sjzik5p.x; smes?

  Mendel observed that there are two possible variations of flower cd .:kz 9yau6tcaxt *f)olour in pea plants, purple and white. After a genetic cross, the ratio of plants with purple flowers to white flowerzukt.c: 6a*f y9a)xd ts is 1:1. What were the genotypes of the parents?

  The graph shows the frequency of birth weight of l +r4s4j ziivnphi8/47p )vkxchildren born in London in 1991. 4474pslixrphi8k /i +v v)jzn

  Which of these traits is an example of continuoxtn p:i(m f;b+us variation?

  Which row correctly describes diploid and haploid cells i : e+wlh2zdf.jn humans?

  The following table shows the diploid chromosome number of a ranga v,:i zgv5o)eswzr4(;wuxle 5v0jjqd +g 1*we of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessi9i oms+ voaam ouzbe/1)0 ,p(ive 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 blood type A had a child with bpja-fupg f7 /i, d4 pie:yf89dlood type O. What are the possible genotyp47duye/9ia,djpff i fp g:8p-es of the biological father?

  Which row shows the correct annotation of the alleles for blooj4z lcx( r2/j*z srjbwbk;g65 d groups?

  Which of these statements are true for allehjt4 (oq9xpc/les?
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 malaria acr4tw 14pa n*6perm,pqf oss the continent of Africa.anw46p 1qt4r f,mep* p


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), feh5m*ki e-x-e1k . xtiur colour is determined by a number of genes. Brow*h-ekxi.ek tx eim5-1n colour (B) is 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 lih lcvy(,qrr.rl *wf7,nked and unlinked genes.

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

Sickle cell anaemia is caused by the allele H:d:w np:;p+oju*oyxoo3kka i05c7 z ib$^S$ . 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 is . f,y3jae6gqmq/;rqj homozygous for brown, long hair and a fem,agrmeq f; q/3jj6q.yale cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for dia lf3+byyy)wb zw:xz2 ad,x*7o mond-shaped seeds (D) is dominant over oval-shaped seeds2owy yx:+byz x,wz3 blfa)*d7 (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 hai x3(:sk6l6a ndl1ywirr (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 carrinw6(klylxr 1i a:d36 sed 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 inheritancc-qxp 51k y 1h9*jnpb8z,nvive of the condition shown in the pedigree chart jp5 9z yb*kncnx1 pv18v qhi,-below?

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

  Which of these statements about genetic disows my3: f bk*/r;o;meamtsi2 *rders 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 normal z wui59n.-mxk ;v,gtjdistribution.

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 theub +v dxfwpeou/n //23e w4xcha*zr-2 pedigree chart is X-linked recessivevfxw a*n2d+w/z h ecb eor /up2/34xu- and not autosomal recessive?

  Different species of living organisms have different numbers of 9dmjy rkxi,k 28c/ngd9 i6td 3genes characteristic to them. The table shows y c99j 8xikkrt/ng, 2im36dddthe 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 colour. If pr sj-ulj -- gq*,ogo)the pea plants Mendel was studying can only be white or purple and follow the rules of Mendelian genetics, whicggr-*p-uolqoj,)- sj h of these statements was correct?

  A biological male with hemoj cj *i*3l2lj*bx(+ -c lcuk7v ;gn1mrjjo6gophilia and a biological female without hemophilia have a daughter without hemophilia. What are the possible genotypes of t jo;b*3**v m jujco xcic2lrj(- gj6g7nkl1+lhe daughter?

  A dihybrid cross was carried out between two sunflower plants (Helianthus annuu;*(v t e oc2sqen:amp)xrk1.z s) 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 levelq2s;*x. etc pm averz1 :ko()n 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 B can have a cjm27o( -twc o htd,g03: pwvmmw8i*ls hild with bltchsdvomw37 -0jlm (* 2m8w g:,pw oitood type O.

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

3.Explain the role of inheritance in genetic diseases.