A man and a woman have a daughter and a son. Their daughter hascg4 ilhbnq258g04v/a ses;sl normal vision, but their son is colourblind. Which one of theqnesh/g;48sc0s2b l a5 gilv4 se genotypes could be correct for the biological mother?

  Which diagram shows the sexub(b fcd0* t,+gbapw0 chromosomes of a somatic cell in a human male?

  There are two alleles for flbh r0;aq 5j.emower colour in snapdragons. However, the result of a cross between two heterozybq0re;.a jhm5gous plants 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 correct6/l7pc7oxrefg g ,k 0x definition?

  Which of these statements is a correct defini0a:xmm9o m3e ption for a gene?

  The diagram shows a pair of homologous(n)0gj7,uex:.m 4i w mfj+hvfpv w3 aj chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were crossed in an exper. a(6 bjcwii;qiment. Which row shows the expected phenotypic ratio ab(ic.;iqj w6s of the offspring resulting from this cross?

  In some animals, the agouti allele causes individual hairs to h0 ,cs/t b1axdgz:j jiar*v0c,ave a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who are heterozygous have hair 1bc,x*za/ r0 ,dvat0j:isj gcs 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 round o0sy9fk5 ctnb3r wrinkled. The results of an experimental cross yielded 315 off0 sby3f9n5ct kspring 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 (D97 sue0 3hsvwqrosophila melanogaster) have 8 chromosomes. How many chromosomes are in a fertilisee3vsw7 h0 uqs9d oocyte of a fruit fly?

  When does the random orientation of homologous chromosome pa4xww61.l nci o *avm,(-p,opt2ls xd cirs occur?

The majority of the genes in the human genome havevc x:ct3o 80jpw8reen5t+ c d2 already been mapped, meaning the exact locat8t nc tdc28xowj3:vc0e+er5pions 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 genes?e esue;un* u8kewr(n 9,w8zg1i3eq *e

  The diagram shows a karyogram of a brown male rat (Rattus norvegicus).ezo5izd r n.*5c59jwr fl/jyod*7p i0j v-c(f Which arrow is pointing to a p ir5ic7p z9.*cd5(o5/enjfz0rjljw-dy o fv* air of autosomes?

  Mendel observed that thekqg q/26 yum*are are two possible variations of flower colour in pea plants, purple and white. After a genetic cross, the ratio of plants with purple floyuqgqa mk/* 26wers to white flowers is 1:1. What were the genotypes of the parents?

  The graph shows the frequency of birth weight of children born in London in 19wc2y6 (blp eo+91.2 ewlybpc+o 6(

  Which of these traits is an example ofg4n-:r29ec w*jx9 lqaj0 thop /*h wfe continuous variation?

  Which row correctly describw)a)flk u;v8 tes diploid and haploid cells in humans?

  The following table shows the diploid chromosome number of ay dbfculce t19e4(m,* range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive allet5-y7wt 6wl pooey /h8le (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 type O. vt 7y +(s-txf;)xg(3r1q ,fqj dfqkmf What are the possible genotypes 1dm3 (fv yr+s7kq ;f)jfqq(,-gfttxxof the biological father?

  Which row shows the correct annotation of thu v0dsen5pnb 45gew6j 0)hve/e alleles for blood groups?

  Which of these statements are true for alleles? k3b qyi/*seubb8 8lf-
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 th b/uwspl9- zu(wz yo n9kr8(o*e spread of malaria acr(oswlzz *o(- uw/yk8u9rnb9poss 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 deterz. )e ..bm pb(s*1*bmo rw/u:fw jdkfwmined by a number of genes. Brown colourjouz*b. mwpb*1mb .s.rwe/k( f )df:w (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 un(9d0zj01rj0t tn qyze vwg+e )h)(l yalinked genes.

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

Sickle cell anaemia is caused by t(n xv5rp)v3h1 *ms vidhe 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 crosvfthoow8 1 hdjqm5wk59 a;5 -as between a male cat that is homozygous for brown, long hair and a female cat thak5va-wh;o m55t woqj 81f9dhat has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamond-sh )ozy zl48fz ;17mb1dbdht7 ikaped seeds (D) is dominant over oval-shape;1l b7z f1z7 zd8htydomi4k)bd 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 to z.,hht0cs.t ushort hair (l), and curly hair (C) is dominant to straight hair (chtth.. 0 uzs,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 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 condr;qrp u b c5fx.1j2i- 6an)mcvition shown in the pedigree chart below?ruxcjf ; a1-5pn vqi.2rc6 )bm

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

  Which of these statements about genetic disorders is/are if zy :4sgh9/rcorrect?

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 traqe fc -ba0(n;cits 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 disordepv q jhk dbr5phgb m(h/58m2p6g8:i ,sr shown in the pedigree chart is X-linked recessive and not auth6,5kh dp8/2mm:g g5is hjbvrqb8p (posomal recessive?

  Different species of living organisms have different numbers of genes charact1ng 8bqfpe* 9wj9.usmeristic to them. The table shows the estimated numbegb9s8qm1 u9ef * wpj.nr 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 characteristics of pea plant 5 cyhrt79,le;mw/va is, including flower colour. If the pea plants Mendel was studying can only be white or purple and follow the rules of Mendelian genetics, which 9t am/5yrv 7;hwelc,i of these statements was correct?

  A biological male with hemophilia and a biological fema)pqn+t -0 wofale without hemophilia have a daughter without hemophiot+w )pa- qn0flia. What are the possible genotypes of the daughter?

  A dihybrid cross was carried out between two suc1u p0 t.(djobnflower 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 calculate(.u jp1o0db ctd value for the chi-squared test was 10.05; what does this indicate?

1.Explain how parents with blood type A wth;zgtg45n 8o6 slb8and blood type B can have a child with bloodwt sb4tho l 58n68zgg; type O.

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

3.Explain the role of inheritance in genetic diseases.