A man and a woman have a daughter and a son. Their daughter had;rry9u,ky 8b+alw7t s normal vision, but their son is bwyr,yal9 dt+;7kr8 ucolourblind. Which one of these genotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a soma;)holzs )y;j4o xyl+ ttic cell in a human male?

  There are two alleles for flower colour in snapdragons. However,)s.wvl4ghd 3l the result of a cross between two heterozygous plantshgw3 )ll4d. vs yielded 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 correct d88dyvtzob )6zi/rff zh wcx068s d-d9efinition?

  Which of these statements is a correct o z;ig9d7+b)ya: bfcldefinition for a gene?

  The diagram shows a pair oftgw 3at 5/wvkyqe(z:. homologous chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specifpv6f tu(cal x:8w3 li;ic trait, were crossed in an experiment. Which rx( u6 8twi3lvclp:a f;ow shows the expected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti allele causes individual hairs to ms )8r n8huhs)have a banded pattern. The non-agouti h ))murh 88nssallele causes hairs to be 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 shar2e1j)fyqib0rw x 67sxip.x7 (2tc tlpe in individual pea plants was either round or wrinkled. The resultprqx01( e6sfwbl. ) xti7ct7 xjr2y2is 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 melan6 znj p)r h:h(q5t *ie*noskg8ogaster) have 8 chromosomes. How many chromosomes are in a feikjp*zq(h* h6 osr :t58n)egn rtilised oocyte of a fruit fly?

  When does the random o-e8k bwq5 -a.ufb jetc,(dp 6f4llfn 35u5f jlrientation of homologous chromosome pairs occur?

The majority of the genes in the human genome have already been ma ky9/ h6wnla5jpped, meaning the exact locations of the genes on chromosomes are known. The diagrama95/ 6yhw jknl 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 of linked g.m1qdl9 t j:lr.thqd,if2d b*enes?

  The diagram shows a kar-ukc74rlz/ bj33 m qlhyogram of a brown male rat (Rattus norvegicus). Which arrow is pointing bk7zq jr ml3ulh/3c-4to a pair of autosomes?

  Mendel observed that there are two possible vjq*i9q/s aqf;lg-l cm):gn5 iariations 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. Whj:lcai-f*q g)/5;qq ln m gsi9at were the genotypes of the parents?

  The graph shows the frequency of birth weigh68wl2yguy 1 cgwa)f-zt of children born in London in 1991. wgzl)ygc82 1w-a ufy6

  Which of these traits is an example ofry /g892kyelj continuous variation?

  Which row correctly descrfzwp i5 dyg(rjx4;y3z *vpl; 0ibes diploid and haploid cells in humans?

  The following table shows the diploid chro;daq ut70d /ommosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive alle1; ku q *zbato+.20eyg(jx u,xn;mej ble (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 b*kml,nkxhz;z vo04:u4 h *wa 1lle, oqlood type A had a child with blood type O. What are the posso4oah m,zukl;* * q4e,l hv0 lkzxw1n:ible genotypes of the biological father?

  Which row shows the correct annotation of the alleles for blood grf3j,o/.h/s cpbjrbo 7,q trq; oups?

  Which of these statements are true for aum o3hwtcx4sif :84z;lleles?
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 +tv,tg1q::zd 4e9 m 5ehlcx;-rryxam across the continent of Africa.zhgrat, 9r; :tem-4ed5cqmy xvl+ x1:


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 (Eq i zosm7aa .lyqm*8d),uus przewalskii), 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 ton)lm zadyq8*,i a.7som e (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 unli5c.sbv bjm 451)nk(vkkof0ymlw34 m jnked genes.

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

Sickle cell anaemia is cause9 elg6u e)py 7pcna-oo5,kzv4 d 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 homozygous for bronydgs:; s; pl9f6 khww(c q6q;wn, long hair and a female cat that wg(c6pnh;;y fskd;6: lqsqw9 has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), t1:hcrua26v:l hwhs7; t5l ggrhe allele for diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) wht7vrac1hus5lg; h:: rg 26lis 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 hair (l), a4c+ :sxc,s)t0 o8zyxogx pj-ond curly hair (C) is dominant to straight hair (c). A test cros, 4c-8)xys x+joxozo gcspt0:s 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 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 condi12axbx e t+;g**vex*tflyh i 8tion shown in the pedigree chart below? t fe1egtlvx**8 hi*y+xa2; xb

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

  Which of these statements aboutca6dca .:kj ,l3d:t; azfff4z 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 traits can show a normal g 3(ypz nkyrm8f1*poy,p1 ff,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 d eg+nj1pu b;s q-04mc97kl1sig3vhz of the disorder shown in the pedigree chart is X-linked recessive and not autosomal rli4 dezc9gmks spbvg 73q0 1hu;+nj-1ecessive?

  Different species of living organisms have diffe(.p.pne7a )bdpvwek 0rent numbers of genes characteristic to them. The table shows the estimated number of genes fo(a npp0veb..k)e7dp wr 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 characteristic.aj7e 42vk)t8uvo : f.ii,nc- kn2g+ pybuiwts of pea plants, including flower colour. If the pea plants Mendel was studying can only be white or purple and folli8eatip .fbw2- )+jg4c,okvvuk y7.nun :it 2 ow the rules of Mendelian genetics, which of these statements was correct?

  A biological male with hemophilia and a biological femalpfm8p;m4h stkn. oi2f(6 sw d9e without hemophilia have a daughter without hemophilia. What are the possible genotypes of t;ppnwk64f82.m(m sso fdh 9ithe daughter?

  A dihybrid cross was carried out betwe7ym j+j,k*wqi en 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; wha k* jwy,7jmq+it does this indicate?

1.Explain how parents with blood type A and blooq3th+ *b4v9mnb wji,y d type B can have a child with blood typeq3ivwytb *,m j+bhn 49 O.

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

3.Explain the role of inheritance in genetic diseases.