A man and a woman have a daughter and a son. Their imxh7ffu /4- ydaughter has normal vision, but their son is colourblind. Which one of i-h7/fu xfy4mthese genotypes could be correct for the biological mother?

  Which diagram shows the 7emi-12zy0j 8dar 3/qkhqkymsex chromosomes of a somatic cell in a human male?

  There are two alleles for flower colour in snapdragons. However, thp++4a h3btt;r y nw)ong23v )w(hcnloe result of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red, white and pink flowers. Which is the most likely explanation for this obserhvp43hty3+c )t;+b ngo)w(o 2lwn anrvation?

  Which keyword is matched to the correct:jvtm* :cz gc; definition?

  Which of these statements is a correct defin3 l9hu ue7n):rrzgj ea.x)wy (ition for a gene?

  The diagram shows a pair of homologous chromorkg2 6;ue* s +qvv:glasomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were crossed in an experimt9)9 xwxco(cjgltaf0 u+t+5 5 lfoq3 vent. Which row shows the expected phenotypic ratios of the offspring resulting from this crc xlfc+wxg9o5+f ( t9 tauv3)5 jtqo0loss?

  In some animals, the agouti allele causes individuv f6.3g- xnfixal hairs to have a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuals wx vi3g.fx6- nfho 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 shab f7rug: r1a8w( oqbd3pe in individual pea plants was either round or wrinkled. The results of an experimental cross yielded 315 offspring with round seeds and 105 offspring with wrinkled sf3a8r:obw (b g7r1uqdeeds.

Which row in the table below states the most likely genotypes of the parents?

  Neurons of the fruit fly (Drosophila melanogaster) have 8 chromzuwbu / u91rl+osomes. How many chromosomes are in a fertilised oocyte of a fruuzb/lu1+wr9 u it fly?

  When does the random orientation;4h cc:lkytpcews 3(* of homologous chromosome pairs occur?

The majority of the genes in the h bb8 y 20ugvr-0/*0oaqaamiv /zlo9owuman genome have already been mapped, meaning the exact locations of the genes ov-0ua0obg 2zl/wvorym aibqo 9 /0*a8n 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 derlo/bazp4vp3 5 pe hvd04a3o,finition of linked genes?

  The diagram shows a karyogram of a brown male rat (Rattus norvegicus)jo4 gf3j2d 5zegsz2 k). Which arrow is pointing to a pair of autosodg53zgeks4 j j2f2 z)omes?

  Mendel observed that there are two posvj)a f yz4x:plqn3a ,*sible variations 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. Whatlpf:x3q)naj *z4 , ayv were the genotypes of the parents?

  The graph shows the frequency of birth weight of children born in Lonl swf( acv,iqy(ix43/ don in 1991.qlc(3a (yi ifs,4/wxv

  Which of these traits u u 7 r**puq flxh0ri6jinm61(is an example of continuous variation?

  Which row correctly describes diploid and haploid cells in humans? mnv -,ij 48qkr

  The following table shows the diploid chro,2oy ayf l1)ey4l v4p-so+ fpkmosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive allele (:a h:fsvl:6 laHb$^S$). 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. t-bqd u) o;m)jwt/2 8ibfofy- What are the possible genotypes of the biologica-)8qt 2dymw/;f)bb oifo-ujtl father?

  Which row shows the correct annotation of y)+bu(dgk, j:rrap;m the alleles for blood groups?

  Which of these statements are true for allelj7l z 5u, q7pl3ny3b 4tm2ymwces?
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 the0bvy (:cvzdi5 spread of malaria acros0v (cbvyzd i5:s the continent 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 (Equ -fr4o ew3qfr r83bdadid/nz) -a05qhus przewalskii), fur colour is determined by a number of genes. Brown colour (B) is dominant to-zdq)d3a db fq8inw0r-3or5 efha4r/ 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 linked and unlinked g(kdkqi rs.5c mhs1z.)enes.

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

Sickle cell anaemia idssp0)gzw2; 46wvsnjf 5 m9 fbs 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: 8unw4f n - bpsaeq0,t/id7lyti78gm between a male cat that is homozygous for brown, long hair and a female cat ta- pqg,e0b7mt8/ sl fu8 tnd:4ywii7nhat has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allelev3uc0 ;o fpti+o3+bcu for diamond-shaped seeds (D) is dominant over oval-shaped seeds (dcto+ u3fic;0ou 3p bv+) 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 por mi g9tat9,uqd+8*dks cellus), 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 guinea pigs and female shortuqtm*tgs d8ik+ a,99d, 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 conditionitten-1f8l. ,.t is9y hrk 5ux shown in the pedigree chart below? rkh.tsyf5i 8-eni ttxlu9 1. ,

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

  Which of these statements about genetic dismqu z g05vk zf:x7uq+/fq2,lforders 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 t-eavfo p+i4f:raits can 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 diso+a kp6clz,i8 jrder shown in the pedigree chart is X-linked recessive andik ,+z c6laj8p not autosomal recessive?

  Different species of living organisms have venqp/k 292z xdifferent numbers of genes characteristic to them. The table shows the estimated number of genes for five speciqzp/vx2nk92e es.
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 wwl9 i,3go;hx a-zt-fof 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, whihwzat- ;, 3gwi9l-x ofch of these statements was correct?

  A biological male with hemophilo,*wlv7 a8: eh3 )fm2bg m)x5k wwrio;iyfep,ia and a biological female without hemophilia have a daughter without hemophilia. What are the possible genotypes of the dawyxelk35wi,bap2 m :m ;*wf7vg)o8 h), orfeiughter?

  A dihybrid cross was carried out between t +jco06v0dp;7ucyigaq 7phs8 wo sunflower plants (Helianthus annuus) to see if the genes for seed number and seed shape are linked. Thv c+7 g7 sy0h0j6cpiqpduo;8ae 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 indicate?

1.Explain how parents with blood type A a nrl *j+b7(zhovd (3clnd blood type B can have a child with blood+bzdh(7 *vrn3 l(jocl type O.

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

3.Explain the role of inheritance in genetic diseases.