A man and a woman have a daughter and a son. Their daughter has normal vpgr2-d,mbvim- t 73g aision, but their son is colourblind. Which one of these gpg ri -3at-vg7dm2,mbenotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic cell in a human mal5l a ,bxyl oo7+gdkz**d vt,:je?

  There are two alleles for flfn mjn) nfs v11m.j v6k5b)yx:ower colour in snapdragons. However, the result of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red,mfn) vm 1sn:yvj 6b f)jnk.x15 white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to the corrjh wu(1gl w5;vect definition?

  Which of these statements is a correct definition for a m+xhwid-.mv5b v(kl; h ccx/- gene?

  The diagram shows a pair of homologous chr vxe8164n1 8p.c ytsku axil)bomosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were crossed in an experimeytm: fz;k lm f5g;yl09nt. Which row shows the expected phenotypic ratios of the offspring refy59z : f;;ymlkmg0t lsulting from this cross?

  In some animals, the agouti allele causes individual hairs to have a banded paxa7gq:5z +6a5vmxlkn l ynz0) ttern. The non-agouti allele causes hairs to bn 60:+7a g5qy)5vnzk lmx lzxae 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 individual pea plants wasu91xam(ug sr4 either round or wrinkled. The r(94suu xa rm1gesults 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 (Dro,g kv f41v8geqaq-4sm 6v-byz sophila melanogaster) have 8 chromosomes. How many chromosomes are in a fertilised oocyte of a fruit fl6-vamk8qfqb -s z gvyv14e4g, y?

  When does the random orientation of homologous chromosome pairs occurzeearfpt5 k/ye(:u1 ;?

The majority of the genes inv nxr8mol3q--fj) n06ibj nf6 the human genome have already been mapped, meaning the exact locations of the genes on chromosomes are known. The diagn3 qnr8-0fjfo- v m )xlj6inb6ram 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 ls 0(ha0gb ;0qco,ttafinked genes?

  The diagram shows a karyogram of a brown male rat (Rattus norvucmyx-x+;y 4regicus). Which arrow is pointing to a pair ;y -rxx yum4c+of autosomes?

  Mendel observed that the9ifzrq2 8u0v/ ; djv::fprbosre are two possible 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. What were the genotypes of 2vs :ub9 d:fvpqr0; zr8 oijf/the parents?

  The graph shows the frequency of birth weight of children born xr q:aym+*7t tin London in 1991.q:* t7m+ ayrtx

  Which of these traits is an example of continu 5 1aczysx07wdous variation?

  Which row correctly describes diploid and haploid cjd3v j(9w u(ze*)m+5hiu fqlnk )7ewx ells in humans?

  The following table shs r, r3mli3a45d igy huqkqso0 0./c.kows the diploid chromosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive allele a p*b ;ntgsn ,a:9g;da(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 witht cjrhax5y3ki 3b n5nj/85m5h blood type A had a child with blood type O. What are the possible genotypes of ct i8n5r 5 5myh3/ 3hajxjbnk5the biological father?

  Which row shows the correct annotation of the alqn(r*q ag-m/62n deyeleles for blood groups?

  Which of these statements are /wc5a;zbuf(j3mv2aj7z d cp) true for alleles?
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 thedlc9o,j:w/g ksmx *igqc 5;1 r spread of malaria across the contin*x dijc9rog 1mkcs 5,/g qlw;:ent 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 przewo ay6-f 7i9gtc3ltr*balskii), fur colour is determined by a number of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) colouotgft -3icbla6y7*r 9r (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 li25a(dy-.; rtb: vdmzzvyn o8 eacdeg/j r21.n nked and unlinked genes.

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

Sickle cell anaemia ishf(4+j2cbo x b 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 x1a)f sii( c/r)sm*da a cross between a male cat that is homozygous for brown, long hair a(mfcs*1asr)ix ad)i /nd a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamond-spb 8gg-s:-fzdk zxeki . e/(4khaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) is dominaep8gx k s:fdzez ik(4.-b /-kgnt 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 t*2 e,s3whs 1 v-fjvjv8sec ku.o 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 short, straight-haired guinea pigs and a chi-squared test (χ2) was carried out on theuj -fhv2sw*kcs813e s vj e,.v 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 inha7f: h zinl4v ck:h(p 9ase(:keritance of the condition shown in the pedigree chart bk ialhh:( sn ::z fae9vk(c7p4elow?

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

  Which of these statementsakpv69xu m m3h1 zj8o/ about 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 distribution lh 7nv09+ceymib/sz3/u2 mcd.

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 iulw*;irc z3tby y zvl 5/:9*wb7lh4zan the pedigree chart is X-linked recessive and wvz*y59b;iy*wzu/3c:alt bl 47 l zr hnot autosomal recessive?

  Different species of living organisms have different numbe;- mt oibgk,d;rs of genes characteristic to them. The table shows the estimated nu ;bmot; ,-gikdmber 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 characteph;7):gx qc fqt z3(8oyl-liwristics of pea plants, including flower colour. If the pea plants Mendel was studying can only -cw:qxoi3 f)pzy8ll;h tq ( g7be 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 havqv nkt+u)r4j 1e a dt1 r4u+kvjn) qaughter without hemophilia. What are the possible genotypes of the daughter?

  A dihybrid cross was carried out betwvo79v6jkaagzv e(5 3- wj z7eieen two sunflower plants (Helianthus annuus) to see iwk3 a5je7769 zaj g-ov(vz ievf 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; what does this indicate?

1.Explain how parents with ,.w;gzjv. x7 h gnl*s),jprjm blood type A and blood type B can have a child with blood type gjln;s vpj ),jrz.7w*, .hgxmO.

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

3.Explain the role of inheritance in genetic diseases.