A man and a woman have a daughter and a son. Their daughter has normal vision, rz7vcn8l o9hl* y;hc2 but their son is colourblind. Wv*;2 9cch87zlnlroh y hich one of these genotypes could be correct for the biological mother?

  Which diagram shows the sex chromo-+): j,mz a xew7r6h-uixswv7 tv hsx5lg)+posomes of a somatic cell in a human male?

  There are two alleles for flower colourj.j5e da4mvq* in snapdragons. However, the result of a cross between two heterozygous plants yielded offspring with three different obse. jva4*j5m qderved phenotypes, red, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to the corzn gs1s gzvq;p)5g(2p0h rhd *rect definition?

  Which of these statements is a cocb .zt3-xe,v7iz7u v)q:suru rrect definition for a gene?

  The diagram shows a pair of homologl3.lt fm*bu5 gous chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were crossed in an expaa*ymfh5 b8zcdc 4k83 eriment. Which row shows the expected phenotypic ratios of the offspring resulting ah 5cdyk3b8f m48c *zafrom this cross?

  In some animals, the agouti allele causes individual hairsn dip/jgt5wo f4m+t2 ( to have a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuals wh+fgj d(24nmto ti5wp/o 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 individual pea plants was either ro5.t+z6d u0l13sj y2z6( tlf mqjwpllnund or wrinkled. The results of an expe6wld3 sz0 l6y .tztnlfp lj21+j(qm5u rimental 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) have 8 c)-w2/ax yyz om+:orjzhromosomes. How many chromosomes are in a fertilised oocyte of a fruit a-z j/x yrwyo o)2m+z:fly?

  When does the random o 1tu)h)ovc5/ k 1qj04jgq hhbfrientation of homologous chromosome pairs occur?

The majority of the genes in the humaprhjry6)*z++cg;3 wfvsi fn 4 n genome have already been mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one representation of j* phr63fz4 ;+swi rgyv nc+)fa 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 genesawj2y/m/ /p r9bk c4tu?

  The diagram shows a kawzhrm t ts y4i zlr5y1y):47m6ryogram of a brown male rat (Rattus norvegicus). Which arrow is pointing to a pair ofm:i 7wmr)s4 5r1zt t6yz yyh4l autosomes?

  Mendel observed that there are two possible varij7 og6yplm.sb kt0p (dc/ e+-pations 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. What were the genotypes t.ksd7g6l0 ype(p bj/p cm+-o of the parents?

  The graph shows the frequency of birth weight of children born 5 .;e9ve3un iksy tobh g7:g8rin London in 1991.b8 nt;7 .oei9 syehrk: 5g3uvg

  Which of these traits is an exampt 44h1bg gt:lnle of continuous variation?

  Which row correctly describes diploid a1p dzd4 3pzlodhrrky)p1 ;+w+nd haploid cells in humans?

  The following table shows the diploid chromosome number of a range of species.0ssd 4apjl8k;

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive allele (xftz,mjdq.y7*a/lt k *d7 xc+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 tywiilc( 3ll)u9pe O. What are the possible genotypes of ucl 3w9i(l) lithe biological father?

  Which row shows the correct annotation of the alleles fpn 9 4kpmmp*k5v :,cdso ns;-ror blood groups?

  Which of these statements are true for allelesn e5v2i-* l+ pp4hzdgz?
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 yex2b72 c0dl3rh+ua v malaria across h2lxye2 d ba+cur3 07vthe 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 colot/ wjt6zy*9ikv5c ri)b2yq 0,qj46 cm uh8 dhgur is determined by a number of genes. Brown colour9 gqjth2tir z 0wy,6d yh8c6j/m4u qb*i) 5vkc (B) is dominant to 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 unlinkemb4d; e9iv,yc - na2vud genes.

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

Sickle cell anaemia is caused by the+lqsi;tgia2gvg- 6 g( 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 uj.9 izxn(6 mxbrown, long hair and a female cat that has black, shormu.9 ni6zj(x xt hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinjy6v)xp(2u bswsw (w:ale), the allele for diamond-shaped seeds (D) is dom:w(wx j2yvsu)(ws 6bpinant over oval-shaped seeds (d) 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 porcellus), long hair (L) is dominant twrv/9l6(, ;blxw 3d asmvaxf -o short hair (l), and curly hair (C) is dominant to straight hair (c). A test cross was carried xwb3a lal,6r v(9;dv -sfxm w/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 condition show1md f-t5) mcax0h6rbmn in the pedigree chart belomtm) 0bhd1-acf xrm6 5w?

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

  Which of these statements about genetic disorders is/are corhu0nj+ vj8l : y-(/cowg gl/rnrect?

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 *mv0f2b ogz6zi 5-hkktraits 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 disorder sh pf2ns6+:xdk jown in the pedigree chart is Xn jfkpsd:62+ x-linked recessive and not autosomal recessive?

  Different species of living organisms have different tjk 3w 1s:zqu7numbers of genes characteristic to them. The table shows the estimated number of genes for js7q3tw uk:1zfive 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, including flower colou8zlq l+;s2m ljr. If the pea plants Mendel was studying can only be white or purple and follow the rules of Mjl 8;2s+zm llqendelian genetics, which of these statements was correct?

  A biological male with hemophilia and a biolog6 e 8ukej:/uusical female without hemophilia have a daughter without hemophilia. What are the possible genotypes of the daughter?ejk:e8 /6 uuus

  A dihybrid cross was carried out between two sunflower plants (r7 p*ey j:evj2kcr* *lHelianthus annuus) to see if the genes for seed number c *y2 l* e:rvj7pr*ejkand 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; what does this indicate?

1.Explain how parents w/nabxp mi(ztu/9 uj+-fy; p 3oith blood type A and blood type B can have a child with blood type O/jmz-3t/o (xubpfypn ;9 i +ua.

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

3.Explain the role of inheritance in genetic diseases.