A man and a woman have a dz-7y 9mw lej:faughter and a son. Their daughter has normal vision, but their son is colourblind. Which one of these genotypes could be correct for the bioe: yf9w7 zlmj-logical mother?

  Which diagram shows the sex chromosomes of a somatic cell in a human s yl/k3m16c v4b 2yfkwmale?

  There are two alleles for f d: h p8l4-r-- .ih6e0plysmgpr6zygilower colour in snapdragons. However, the result of a cross between two heterozygous plants yielded offspring with three difyzleh86gi p6.:0 g pmr4phi-dy l-r-s ferent observed phenotypes, red, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to the correct:zl03: ikk2ho 48 asi/ agtlhm definition?

  Which of these statememao9 +;rb a)f7p flma+nts is a correct definition for a gene?

  The diagram shows a paiic6 :*2zciwe. z1ov5xglx a .qr of homologous chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specificc1/idcc, )ywfma1 y k) trait, were crossed in an experiment. Which row shows the expected phenotypic ratios ac )y yf1cw/1cmidk),of the offspring resulting from this cross?

  In some animals, the agouti allele causes indivzmtw2k iy31.6;ct uhtidual hairs to have a banded pattern. The non-agoutithc;t21w 6yi ut.k mz3 allele 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 shape in individualay ; d z v-df1;sm:p(vtj,d;f/fyrhn- pea plants was either round or wrinkled. The rtrhfvn zd/dy;f ;p 1 -sdfv-yma:(j; ,esults 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:+gr rrq83j0u0avuj+aye,d wcwvj6 - xiek 1:) have 8 chromosomes. How many chromosomes are in a fert0+3g cayvwur q: wa k0:j, ed-6eriv8 +jrjux1ilised oocyte of a fruit fly?

  When does the random orientation of homologous chromov 4;w13rhtp0.d gec fcsome pairs occur?

The majority of the genes in the human genome have alr shg)4gs55 9ljetf i-veady been mapped, meaning the s9 5seg-5jltf)hgi4 v exact locations of the genes 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 of linked cv kv)-e9jv:o0 6ixbj genes?

  The diagram shows a karyogram of a brown male ryd,miy;g g7t4at (Rattus norvegicus). Which arrow is point4,mdgyy g i;7ting to a pair of autosomes?

  Mendel observed that there are two possible variations of flower colour i7 (tuwwug.2nptw 12df n pea plants, purple and white. After a genetic cross, the ratio of plants with purple flowers to white flowers is 1: 7n1u(tg 2u2w .wwptfd1. What were the genotypes of the parents?

  The graph shows the zj*9-y l; zuq1 wrxm.rfrequency of birth weight of children born in London in 1991z wu -zy1*x;rqjlr 9.m.

  Which of these traits is an example of continuous variatuio+b-m* 9mqg xsm5 u3ion?

  Which row correctly describes diploind ,19;k 2gt+m4xzgdxog ok-cd and haploid cells in humans?

  The following table shows the diploid chromosome number of a range of spe5w5+l m3 g8 zrbmztk+r o.6beacies.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive al, )a1x uqladn+lele (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 wil5mkz5d q41t vth blood type A had a child with blood type O. What are theqzv ml54t51d k possible genotypes of the biological father?

  Which row shows the correct annotation of the a6dx*xdiv qvyh+bc.; (lleles for blood groups?

  Which of these statements are true for alleleskss,c*oas6c 3?
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 silew,y u t,-jnz.a uz.8nf+a 0pread of malaria acro.a fw.tzu,-nejly u,n+8iza0 ss 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 (Equus przewalskii), fur colour is determined by a numbld.b2c* m -ugier of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) colour (Pcil-*mb2 . udg) 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 l p if5;ll,pm/ ob)qv,pinked and unlinked genes.

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

Sickle cell anaemia is caused by thm 0lu)i:ue9ho e 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 betmp(+cv89 yoq yween a male cat that is homozygous for brown, long hair and a female caty8q+movyp9( c that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacvl5q4a dyyw;b-86 dohdwc e1w ;o /o4bum officinale), the allele for diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) is dominant over short seedsb5ddeaw4;cql-6/1owvo4 wb y8;h yod (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 dominantm a6rha(,ykg;of51 j r to short hair (l), and curly hair (C) is dominant to straight hair (c). A test cross was carried out between male heterozygous6hykfma5 go( ;,rarj1 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 f )mf k :,cdjjtu:u81d8s. hmscondition shown in the pedigree chart below? :f.duf,m mhu8djk js: 81cs) t

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

  Which of these statements about genetic disorders is/are correct? . tiouxt7u)qpp2)1 )nlxf m*h

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 showgee ( yc-:(d,yi3. gcno hs7tr 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 char96k8 jauq jyo2uomi .+,lgy3nt is X-linked recessive and not autong6j8,ik yujmal + qu3oy92.osomal recessive?

  Different species of livingi5 q ip8 pwtapjgp( cpm21-u94 organisms have different numbers of genes characteristic to them. The table shows the estimated number of genes for five species.tj48p(pp wqim 9ag upip1c25-
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, including flower colour. Ico7eh4w1c klw44:t zwf the phc7o kw 4c1t4:wwe4zlea plants Mendel 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 *l:qnbezu1*f7y;/ c /2aczvabw r-iowithout hemophilia have a daughter bn1qicz:-o e* 7varf /byz2uw/a ;*cl without hemophilia. What are the possible genotypes of the daughter?

  A dihybrid cross was carried owe* fa;r+82 zfr dcj5tut 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 atcjff a8erw 52t+z*;dr 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 parents1d rmevl*dh1) n5m9b s9sx4nj with blood type A and blood type B can have a child with blood typ m) 9vm sshn1xe 5r4d1*jdlbn9e O.

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

3.Explain the role of inheritance in genetic diseases.