A man and a woman havkry*l ,mpp5nz,r 39uf e a daughter and a son. Their daughter has normal vision, but their son is colourblind. Which one of these genotypespu,n prr9mfy, kl53z* could be correct for the biological mother?

  Which diagram shows the sex chrooayb-+2 7,emxruhz7 i5hi ,, xriwg;amosomes of a somatic cell in a human male?

  There are two alleles for flower colour inju fx8piwi-w1w4d6 etk n0e w,d/c9q; snapdragons. However, the result of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red, wh w96ded1eu;tqk8 ij,wiw0wxc- 4fpn/ite and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to the correct de i)y:sct6cs+,q/)vis)y phw ,ds md3efinition?

  Which of these statements is a correct definition fo60)txq glhiqit x)zy*)taq.3, dbt e;r a gene?

  The diagram shows a pair of homo8/x9sn ro-gsy logous chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specifi*u:jbg ; n4jqmc trait, were crossed in an experiment. Which row shows the expected phenotypic ratios of the offsprinbjgnj*;m : 4qug resulting from this cross?

  In some animals, the agouti allele causes individual hairs to have a banded pattk/uhx)58gsdy ta7 do ,ern. The non-agouti allele causes hairs to be a single colour. Individuals who are heterozygous have hairs with a banded /yg5,) hx8a k7osdtud 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 ldbxu;g9 80c ohe8fm zs23k(zin individual pea plants was either round or wrinkled. The results of an experimental cross yielded 315 offsprin2ul; 8zx kh3mzbcf(ogsed 890g 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 ee7;4jbbhe5e fly (Drosophila melanogaster) have 8 chromosomes. How many chromosomes are in a fertilised ;he5b beee7j4oocyte of a fruit fly?

  When does the random orientation of homologous chromosome pai/kbe4xr . 6kq3ucc1o h (7epyars occur?

The majority of the gene rzju*pr*v2i3-* z 2ap6od zdel5an/is in the human genome have already been mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one representation of a homologousi /ro* p rnd5apv 36az2*j uzzlei2*-d 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 definrj2de;(sl /0ojkc)0e 5azaiy xb (3i fition of linked genes?

  The diagram shows a karyogram of a brown2fxox e4(zpnzaq g24- male rat (Rattus norvegicus). Which arrow is pointing to a pair of autosomes? 24e( -gqnxzp2zaf x4o

  Mendel observed that there are two possible variations of fl8ei5.mjgmtj uof7e7fzj qo76( vtt 87ower colour in pea plants, purple andvmmg j7oo8.te 6qu5ft 7t(8fjj77ize white. After a genetic cross, the ratio of plants with purple flowers to white flowers is 1:1. What were the genotypes of the parents?

  The graph shows the frequency of birth weight of children bl4 0ypstc0 ();kqhgfq orn in London in 1991. kqhgt)40 ;sf ycpq(l0

  Which of these traits is an example of continuous variatw ;vrg/ef6/ stion?

  Which row correctly dpncgyw-k/ w ),-.wadgescribes diploid and haploid cells in humans?

  The following table shows the diploid chromosome number of a range of 3j 7fp1y0 idhvspecies.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive allet ;u)rnkluc5oohylz ;;c- t*- le (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 typt2ti+6ik gkm( lg4bt1e O. What are the possible genotypelt mt1k2gtib i4gk(+ 6s of the biological father?

  Which row shows the correct annotation of qxo:j :,d6ec 9-pvqcq the alleles for blood groups?

  Which of these statements are true for alli gk7d52j,u;1mwz v(ye3u zdw eles?
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 crd:;xi7w,n 1(q9 giis(qqrmsickle cell anaemia and the spread of malaria across the cont;qr,i7 xrin9i(m( w qq:gs1cdinent 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 przdy:s3;fc,k-fcw uvjx:;hpzv 9z3,ke (dl 1ynewalskii), 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 of(ky9;:3d,;vxlhd,cz3w zysufjekc1 pv n -: ne 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 and unlinxt2k-mlya fqv1a8l2ft 10 y.e ked genes.

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

Sickle cell anaemia is caused by the allewhuajhu+ jp ,h )l5lyc5c+q6a6ma7 t.le 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(89ygx57hr lt x- glkm a male cat that is homozygous for brown, long hair and a femagg8t xl-(y7mxl5 hk r9le cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamond-shaped seeds (c 7k agzvz-*6rD) is dominant over oval-shaped seeds (d) azgkz v6c-*r a7nd 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 a3r6n8ef2 fp; q6u npd*ud*6e-jpp pfhair (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-squa;6e8 -ep qju3np6fdu2*npf*d6 r f ppared 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 condition shown in the pedigree chas 4njpv4y+gc* rt belojs*4 c+np4v gyw?

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

  Which of these statements about genetlcun7+ aqm keuw,)*3 iic 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 show a normagqul.2oj* a, pl 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 pedigff715b o8 ydapzn. 2qcr 2u)fnree chart is X-liqnb7 ) rnof8f2 cf.yz12da5p unked recessive and not autosomal recessive?

  Different species of living organisms have different numbers of genes chb )udy8ykmhei, i.p8sqp08 bj)1f/jaaracteristic to them. The table shows the estimated number of genes yijqk f1/mu 8iy sb,dh)epjap.)8b08for 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 charactelelo ha9 dsl e6q+,wxf2p-3s :ristics 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, 92xf,:eoql a shw3 de6-plls+which of these statements was correct?

  A biological male with hemophil2 b+b+ssw-u s.s+(fo(mg.nymt- tvvmia and a biological female without hemophilia have a daughter without hemophilia. What are thett nmsm++ov. vfb-- 2+((gws yssmb.u possible genotypes of the daughter?

  A dihybrid cross was carried o7 wedl2 .zzrd9 ypo:x )2fmn p)q(4kvkut between 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 : opw7vp2frqdm 2. 9)4l)kx(ekzyndz 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 typcipi:4pc 1+ yee A and blood type B can have a child with bl+1yep :ipcc4i ood type O.

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

3.Explain the role of inheritance in genetic diseases.