A man and a woman have a daughter and a son. Their daughter has nor4cs iyix4(13 g7xipg;yb7x qc rv.e7amal vision, but their son is colourblind. Which one of these genotypes could be37 cxai 7 ybr s1.iqxg74p;cyieg(4vx correct for the biological mother?

  Which diagram shows the sex chrog m/smlmeu+2 +mosomes of a somatic cell in a human male?

  There are two alleles for flower colour in s ./dk4wy eiz 6x:lx et9);mowcnapdragons. However, the result of a cross between two heterozygous plants yieldedoy.9wxc e;t z6l:)dekix4w/ m offspring with three different observed phenotypes, red, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to the corr; kpcdz*mxi*;0+ sp pzect definition?

  Which of these statements is a correct definitig8c(k * yswcp+on for a gene?

  The diagram shows a pair of homologous c 7cwln) )zcz1h)3;sofgktpf-hromosomes.

How many loci are shown?

  Two individuals, heterozygous for0pw*o/z2tf mt a specific trait, were crossed in an experiment. Which 2 omt/*w0ptfzrow shows the expected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti allele causes individual hairs t4 ,a3s ; vigigvr1;milo have a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who are heterozygous v,;;1r visa4gil3 igmhave 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 sp mdzlwi.i :ou0) ily+ )b(i+the seed shape in individual pea plants was either round or wrinkled. The results of an experimental cross yielded 315 offspring with round seeds anpiz +iwd 0biuys )(li)m+:o .ld 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 melk;h c /j+b,wglanogaster) have 8 chromosomes. How many chromosomes are in a fertilised oocyte of a fruit flwkjlg;,b+ ch/ y?

  When does the random orientation of homolo2mv x5zitn 0di:q2a )ogous chromosome pairs occur?

The majority of the genes in the human genome have already been m,1ufk9; of 2 ,v xw1umzqtyd*eapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one represe9,; k u1dt mqfx zo*vfu2yw,1entation 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 linkedyod(vu0sgg((n q,l3 f genes?

  The diagram shows a karyogram of a brown male rat (Rattus nomg)i15z c0gx q6*lnuy rvegicus). Which arrow is pointing06uy g n*ximc5lg )q1z to a pair of autosomes?

  Mendel observed that there are two possible variations of flower colx)4u6x xm) wvvk7v+tgf8i5ptour in pea plants, purple and white. After a genetic cross, the ratio of plants with purple flowers to white flowe8g)5tiv) vf76 kw4x vpxxmut +rs is 1:1. What were the genotypes of the parents?

  The graph shows the frequency ogbxo nbq 1t1/l (.,iyuf birth weight of children born in London in 1991.(i ut,.1 lb bnx1qygo/

  Which of these traits is an example of continuousqohz3 k2h,m /n9y3zc q variation?

  Which row correctly deqcv06ckv(3 :(u)prbd;q mj ra scribes diploid and haploid cells in humans?

  The following table shows ttt thj+nlnwgat3 a4/.hm, n:0he diploid chromosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is causa of; *v(n k3qns:lc,hgr r3l4ed 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 with blood type A had a child with blood type O. What ar;0+ibx ( xxxbhw yp ad*4d5.zne the possible genoth*n y ;i +5axb.z4xd(wx0pdbxypes of the biological father?

  Which row shows the correct annotation yko)bu )dw- ,soxl(pcup),tc0ztl 21of the alleles for blood groups?

  Which of these statements are tr0oj sy) zr(qz7ue 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 ;8s+h*xq(/i*bo/vbto,e. ykmln w cfthe spread of malaria across the continents n,/t*he;fko v .lm8qy(xc/+b*o ibw 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 przewalqle*r5 9dm2v0z9fo 7wiy4ssj skii), fur colour is determined by a number of genes. Brown colour (B) is dominant to sanzfy v2940io dsrj7se ql*m 59wdy 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 linked anc u2n8 )c,qjped unlinked genes.

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

Sickle cell anaemia is caused by tikh0hw gt3j 97he 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 male caxx;k;1f)zp 3* cquyx ft that is homozygous for brown, long hair and a female cat that has black, sh z;x1xfqx)f; cu3ypk*ort hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamonp 79me1 f99+ nqgodhtbd-shaped seeds (D) is domgtb+eq dopm9hf 7 n991inant 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 (L) is dominant to short hx b9/xj7dzz8e,+whmezq; li ,s.6tveair (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-haire9+,x z7dieb ,jvz;qez8 xsmtl h6.e /wd 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 cgn;s,+ue/ vz vk.(c k/nwdu4inheritance of the condition shown in the pedigree chart belo c/e;kg/+uz uk. nsn 4wd(vv,cw?

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

  Which of these statements about geneticbfj- mec+j hky (,tv22 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 sj m4w0sq)hzc( o+,w rehow 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 c:mq-k xq xc-;chart is X-linked recessive and not autosomal recess q-mx-q;ckcx:ive?

  Different species of living organisms have different numbers of genes charaz+ (enaam69gi ol.)q octeristic to them. The table shows the estimated numb9ea .nm6+)g z(lqoaio er 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 b/ (m9ia/hsw5;gnlb7-r qgkepea plants, including flower colour. If the pea plants Mkhb/-(qm ea7s wig;bgrl n59 /endel 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 biologica0y0k9w.4al jzki)etd.d. p(4eozy ctl female without hemophilia have a daughter without hemophilia. What are the possible genotypes of.0do4 zl0ktydez t.4 9pcjye().kiw a the daughter?

  A dihybrid cross was carried out n r.ec/+thi e0between two 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 the chi-squared test was 10.05; what does this inic/hnrte0. + edicate?

1.Explain how parents with blood type A anmdwa6 ldw qjn+;1or3 (d blood type B can have a child with blood t3dmro qwl;6n+dj1(a w ype O.

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

3.Explain the role of inheritance in genetic diseases.