A man and a woman have a daughter and a son. Their daughterg+w3odxd .i(z,sobs 3a7m tx0 has normal vision, but their son is colourblind. Which one of these genotypes could be correct for the biological mot sdo3+0dz.t7ixmxg(boa3,s wher?

  Which diagram shows the sex chromoso:(w6 ufb: i3nupl4r))v2 k ojjezt -w7z k*ooimes of a somatic cell in a human male?

  There are two alleles for flower col 2vf,.ocko, czour in snapdragons. However, the result of a cross between two heterozygous plants yielded,zvof2 .occk, 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 correcr b x*q: :-esjetx9w re2epmmq91 h8y8t definition?

  Which of these statements is a corr.5fogaz,c +)3g etbcbkc71yrect definition for a gene?

  The diagram shows a pair of homologous chro6w 0b; h.r7bnv:tp akyu 71v-ezll7hs mosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific tdd ;kpt6udl6pi/g,wiqm1pr+c43 ;y vrait, were crossed in an experiment. Which row shows the expected phenotypic ratios of the offspring resulting from 6dgy 6ip qk4lv31iru+w ,dd;pp cm/t ;this cross?

  In some animals, the agouti allele causes individual hairs to have a ba-upc 6/ ,z *nrfsofqc;nded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who are heterozygous have hairs with a banded pp uocs-; 6fn*/zfr,cq attern.

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 waq279f pkrw k5ks either round or wrinkled. The results of an experimental cross yielded 315 offspring with round seeds and 105 offspring with wrinkleq2k kwfkp 59r7d seeds.

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

  Neurons of the fruit fly 8:v.z+ws h efij zk1q/(Drosophila melanogaster) have 8 chromosomes. How many chromosomes are in a fertilised oocy z/k1 qe8:vjihw.sf +zte of a fruit fly?

  When does the random orientation) z)cp*8mq ssa8em4i u9ayxc ( of homologous chromosome pairs occur?

The majority of the genes in the va0y,26 1 qveekhx cwah8-y 1ehuman genome have already been mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one representation of a homologous pair of chromosome 02h 8v e6,xywkchey1 eaa1v-qs.

1.Define locus.

2.Identify the number of loci shown in the diagram.

3.Distinguish between gene, allele, and locus.

  Which is the correct definrwlyoe ((7l7eition of linked genes?

  The diagram shows a karyogram of a brown male rat (Rattus norvegbkacx +a9nhc8.i xt2 (icus). Which arrow is poin axix.c(89h kntc+2abting to a pair of autosomes?

  Mendel observed that w .)u29h 4wftadg* hmhthere 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 genot )f9ug2* 4wh.dhwhamtypes of the parents?

  The graph shows the frequency of birth weight of children born in L1:l .62irhyrm 5q(xf,m kgpz vx ry(i/ondon in 19911rziqv:yr y5kx(6g,2i lxmp(/h.mf r.

  Which of these traits is an example of continuous aod )iq2w56c*jk e c;avariation?

  Which row correctly describes diploid and haploid cells iaprvp 27 eryi3/x yu;h)*mn8c n humans?

  The following table shows the diploid chromosome number of a ran:li :nakz/.c1t o nbt)ge of species.

Which of these statements is correct?

  Sickle cell anaemia i ,wx-bl +g:lxbs caused by a recessive allele (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 auw4b8qc (2why jjy-)znrq 47y child with blood type O. What are theuc7y 4yjwzjhyqw-8rnb )2 4(q possible genotypes of the biological father?

  Which row shows the correct annotation of the a j.y0zh00/h+ xyxfl fp isr:p,lleles for blood groups?

  Which of these statements are true for allelei.pmpah7et /s6yj3f k5; qv( ps?
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 malaria acrkl.hzk97ymsx/ a-n l*7 jw;le z 6kqu*55zpbsoss the continent of A9s*lw -ujpxz5 . e6zl/hlykzbm; k 7 *q7nsak5frica.


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 uo+ kirr 71l0wjm8s p,m9jl3cis determined by a number of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone)c1pl+9u7 8jj0ri l k3s,rwm mo 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 lav a slu*s,+-f76tz alinked and unlinked genes.

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

Sickle cell anaemia is caused by the allmrmh2 mwus8yqkr,1o og/z063ele 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 sh3xj mni u5f:0pj3ex5 cows a cross between a male cat that is homozygous for brown, long hair and a female cat thpji mex0 5:3cjn53ufxat has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele fq/rpk,4 meh:;aqtay6bem,s ) yyc 1 3bor diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds p1a3ey;y q, :,ecashrkbt y4 m/bq6m)(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 dominanypmfu3q1ut +aab/ c s :k4 s8gfx31,fkz8l4cq t to short hair (l), a/,88qfm+3k1:caz 34bgtskyuc1 sq f4ux p aflnd 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 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 conditim4j p*t( h;e.fee:xpoon shown in the pedigree chart below .pp(:het4*xeem;jf o?

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

  Which of these statements about genetic disr+9+a5tohsk (6kdydjio*s 1p orders 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 5/ 6gotlc*dbhshow 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 in rcmgs-f/jq zp255n qn62z hb,heritance of the disorder shown in the pedigree chart is X-li-z 6m5gn2rp, sfc bq2j/hqzn5nked recessive and not autosomal recessive?

  Different species of living organisms have different numbers of genes charactes-2 nj wwut1zm qu3q4*ristic to them. The table shows the estimated number-2qs zu1m4*tw 3jqnw u 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 characteristicx6g9bd0;lcq w/ f-v p9c4nv/da na/eus of pea plants, including flower colour. If the pea plants Mendel was studying can only be white or purple and folloua a6/e 0qfvw;-4xnl9d 9nc bpd/cg/vw the rules of Mendelian genetics, which of these statements was correct?

  A biological male with hemophilia and a biological female wr0 u j svrc-2fe:kt-fkss+,c2 ithout hemophilia have a daughter without hemoprtv2u:, cfs+ srfkk-ej-2s0chilia. What are the possible genotypes of the daughter?

  A dihybrid cross was carried out bo9 ;b9cotqu5r etween 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 at the 0.05 significance level was 7.82. The 9qbtrcu9 5 oo;calculated value for the chi-squared test was 10.05; what does this indicate?

1.Explain how parents with b-vi bupqcz292y 2s n(uzc8yqlm *3/h blood type A and blood type B can have a child with blood type 2c/iu*lnh9b-pq2 (vymb2y3 c zqsu8zO.

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

3.Explain the role of inheritance in genetic diseases.