A man and a woman have a daughter and a son. Their daughter has normal n k9uxxu wrh1fri-0*wu 7s )8lvision, but their son is colourblind. Which one of these 8*-nuru i0fsx9uw1hrwlx)k7 genotypes could be correct for the biological mother?

  Which diagram shows the seh8u(/f0 dow2 l.woynux chromosomes of a somatic cell in a human male?

  There are two alleles for flower colour in snapdragons. However, the result ofxya :q2em6o:uqy8j6b:lr) bi a cross between two heterozygous plants yielded offspring withx: 2rbqeiyq 8 aum6b:j yl)6:o three different observed phenotypes, red, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to theqcr+aq,bog8g uek7n05 -: oiz correct definition?

  Which of these statements is a correct definition for 6p lik6j,qm u3-+)veve9qebd a gene?

  The diagram shows a pair of homologous chrombfcqt5oh l1(m 7fc*p0osomes.

How many loci are shown?

  Two individuals, heterozygous for a spe,.wsjx5q) 9/v mutc bbx(m 7xjcific trait, were crossed in an experiment. Which row shows the expected phenotypic ratios of the offspring resulting from this cross9,b. xjw c u vq(7)sj/xb5xtmm?

  In some animals, the agouti allele cauiv :vi1wm8go ,ses individual hairs to have a banded pattern. The non-agouti allele causes hairs to bmvw1v i:,gi8o e a 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 in oy-7dj 3gm.e+kbge t9dividual pea plants was either round or wrinkled. The ree7.go9dj-mkeb yt3 +g sults of an experimental 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) h;fo awp.r v.825 s -wc 1cz1f5frbncftave 8 chromosomes. How many chromosomes are in a fertilised oocyte o 58 vfrotw1 crw nc5sc1.a.2p-ff bz;ff a fruit fly?

  When does the random orientation of homz7;a hma +u9ptologous chromosome pairs occur?

The majority of the genes in the human genome have alre5muht7y*5zu h j3 h0sb(dcdi7 ady been mapped, meaning the exact locations of the genuymu 3i(7jc50sb ddhh*5z 7htes 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 ofxcqj ibhhf,l-ygg(b *0,zb. ;o-v s: o linked genes?

  The diagram shows a karyogram of a brown male rat (Rattus norvegicus). Whif2 h,k;f866:cuoxt gq.tzu n ach arrow isxc68;qga tuth k:6u zonff 2,. pointing to a pair of autosomes?

  Mendel observed that there are two possible variations of flower wpvlzpo1m :x 920jflz70 (t5gd4 jvovcolour in pea plants, purple and white. Afljlm1x t(240v:vgjzz vwdp7 5p0 o9fo ter 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 childreqbp lu24 kr iyr0vy+(al;4 q:un born in London in 1991. 4p:r24;0 q lb kirlvyq(au+yu

  Which of these traits is an examp5)5awaa2rjvzbyk . k y p1z-,z dm29gble of continuous variation?

  Which row correctly describes diploid dz r(hqgla:c,b 04t-u ((yat rand haploid cells in humans?

  The following table shows the diploid chromosome number of a range o0 z-f/g6 x9tpvjb7zulf species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessivm ihfb+7. + bbx4u9iymu4 m 8qfbw83kre 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 chilyly;/d l6 vek5eg 1wu38tecf-d with blood type O. What are the posseylv86lef5ck;-tgwy1u d 3/e ible genotypes of the biological father?

  Which row shows the correct annotation of the alleles for blood groups:fb9 2jn0e9sd mmod4i u xt 29/xq*kzh?

  Which of these statements are true for alleles? d. xumjz,oi;t0 +x,gb
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 spreado(bg /pb+jj g63 tc2dl of malaria across the continent of Africac2tlb 6jg+jdb3/ (g op.


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 determineg59x-prhugd0 ag3mj)d by a number of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) colour m0 hrp 5- jgg9g)ud3ax(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 m3kh l.e), mf;pwy,kd and unlinked genes.

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

Sickle cell anaemia 3wq 0hmu :tzq/is caused by the 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 cat that is homozygoju;ee+h tqef( tiw+30us for brown, long hair and a female cat that has black, shortj tqe ;(e03wehi+ut+f hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamond-shaped seeds (D) isau vmah93r:3ui0i. p ;cj cib0 dominant over oval-shaped seeds (d93 i rha 0ca:mu.ivb3 pu;0ijc) 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 pwvd: odcu/k i5 b1+xbwb76p+uorcellus), 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 guinp +wubv6:ki/d5x7d wb obc+1uea pigs and female short, straight-haired 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 inheritance of iibjsi )+:m-c the condition shown in the pedigree chart below? s :cii +-mjbi)

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

  Which of these statements about genetic disorders is/are correct? lhd 7* d isrirs)m+bew.90e 1y

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 n6vhl yz,j)6ee7r0 eq9,v xokcan 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 the disorder shown in i l7 7q 8wv;ghcxsq 2wr6mnp0dh1 i1+sthe pedigree chart is X-linked recessive an7w m qiq7nxsw61sh h0+21;iv cg8dpr ld not autosomal recessive?

  Different species of living or:4 7evft3u 3 sb/bf oxe8xftl fe97k9xganisms have different numbers of genes characteristic to them. The table shxvx/:8l7kof 3 f9sbe7tx 9efb eu3f 4tows 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, incgz4dmh)x 4ten ps; ,8nluding flower colour. If the pea plants Mendnm ,gd ;)eps4xzt8nh 4el 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 biological female without hemophilia hyya0 q6kzumql:g+* ,eo v8 ra1ave a daughter without hemophilia. Whaturo1k:0q +l6myvyq za gea,*8 are the possible genotypes of the daughter?

  A dihybrid cross was carried out between two sunflower *f:l ho5f1h :w(vphlspv ; m1pplants (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 significan1 vp mplhwlhsp:v*: 5(1;hffoce level was 7.82. The calculated value for the chi-squared test was 10.05; what does this indicate?

1.Explain how parents win.xn0,cf5zz g zo8pl ,th blood type A and blood type B can have a child with blood n,fz,zl n0g5.cozx8ptype O.

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

3.Explain the role of inheritance in genetic diseases.