A man and a woman have a daughter and a son. Their daughtefhl*a/rhi -. pr has normal vision, but their son is colourblind. Which one of these genotype -ri/la*p.hh fs could be correct for the biological mother?

  Which diagram shows the sszezc r8w4*a ,ex chromosomes of a somatic cell in a human male?

  There are two alleles for flower col.awb nauez)59;l ifam4;fr 4aour in snapdragons. However, the result of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red, white and pink flowers. Which is the most likelyfrb)l imaa9 .4wn uf;;zeaa4 5 explanation for this observation?

  Which keyword is matched to -t7yfx3zposst9vh fbxbc)ki8b 1v3*+ q6uu5 the correct definition?

  Which of these statements is a 2,cyqv0+adyo w1k mv2v *2ttgcorrect definition for a gene?

  The diagram shows a pair of homologous cusi 2z0dycwtxl5-,gv .5 e1k yhromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were crossed in an experimcg/m;6o 5 /w:cgzoj nt2ij(sv-as bj -ent. Which row shows the expected phenotj/v- zn2t-5wmcbajisg ;:(o6oc/jgs ypic ratios of the offspring resulting from this cross?

  In some animals, the agouti alz 7xdlor(:9*t t4wek glele causes individual hairs to have a banded pattern. The non-ago7(l: e9tdt*gr z 4xkowuti 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 individual pea pl9+zeev;vg ok a(x0up4 qce 3/tants was either round or wrinkled. The results of an experimental cross yielded 315 offspring with round seeds and 105 offspring with wrinkle+ee t4v; zcqe3ux/0kp9ag ( vod seeds.

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

  Neurons of the fruit fly (Drosophila melanogastero:: p3iaxt/.lp+qryg ) have 8 chromosomes. How many / +:taq giyp3.xrpol:chromosomes are in a fertilised oocyte of a fruit fly?

  When does the random orientation of homologl3mb5g mbjkmq: k:f+ /ous chromosome pairs occur?

The majority of the genes in the human genome have already bemdj. r62mr :eden mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one representation of a homologous pair of chromosome2mm:rrd .je 6ds.

1.Define locus.

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

3.Distinguish between gene, allele, and locus.

  Which is the correct definitijj n5t mpf1bg abm7t:iq;35(eon of linked genes?

  The diagram shows a karyogram of a brown male rat (Rattus norvegicusi6 asj*etgc (m6.u, fzgx7 +kc). Which arrow is pointing to a pair of autosomes? (7cjgkmxf a su6*e. i 6+c,ztg

  Mendel observed that there are two possible variationl-n, yi1 9dqx,qrl;fxn)ff v/s of flower colour in pea plants, purple and white. After a genetic cross, the ratio of plnfvr;)fyx /,19flq l i nxqd,-ants with purple flowers to white flowers is 1:1. What were the genotypes of the parents?

  The graph shows the frequency o h3bh 1wt2sdwd.6g .nwf birth weight of children born in London in 1991. swn .t1.dwgbhh3 6d2 w

  Which of these traits is an example of qcw0.d8msmaak1j08 yecq,)a continuous variation?

  Which row correctly describes di+lhd-*3eqz hf* a1hu;v0ukq nploid and haploid cells in humans?

  The following table shows the diploid chromosome number of a ramfzgw7 8o+ m 1ieu:vi5nge of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive allvtbw- ./mxpm.z w4ri9 ele (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 typdl-8mu-g- gayscd -./ qfli5h v it0:ue O. What are the pgh0:a 8vi5fuy /m udd-- tlc-gq-s .ilossible genotypes of the biological father?

  Which row shows the correct annotation of the alleles for blood groups?zi77etj3*n8 udc d ;ya

  Which of these statements are true for allelesf7 zap ps;9uo0fo: +vfdn lt16?
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 anafo;g dspugt mx z46l8i*xu()1+hlb r1emia and the spread of malaria across the continent of Africa. ur*1otimg6sh4d) 1;l8(f zgblu+x x p


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), fua++oij konq; yb(z .1w1x1tlha svt61c1xb x,r colour is determined by a number of y xq11s1 n+1kxwlt(o 6tbaxc1,;zijb.ovh + agenes. Brown colour (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 linkedaw/i 2wd 8txiq2vwl;3 and unlinked genes.

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

Sickle cell anaemia is caused by the3+qz.;budivhsb8 e(jm 9jn9t 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 homozygou bbzg5) (1d e,w mz( ocsejy./e*sx4ces for brown, long hair and a female cat t4b5 ej) /eed1zys(*cgs z.(wc, oxebmhat has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamoh2l .z 8qce8m-ep9t(6dim mlf+1 hwgjqc o)x 4nd-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) e.hm tgqml9qec ) 8dxwo4-f(p1l micz6j+h8 2is 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 dyvwrncuuu 2n8lc4-x;n wp:9.ominant to 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-squucu.pc4w- n;:y rnlnw9 8xv2 uared 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 az(k kro:l+n 5so )sqh)0l(uzof the condition shown in the pedigree chart blz kk0az)orn5s ()hs+l:oq( uelow?

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

  Which of these statements about ge7a1 s-zrrk+*bqa mw 2jp(.yvvnetic 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 5es n;6y1dxfsdistribution.

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 th* .z5fd1ftyt k,9bdjce disorder shown in the pedigree chart is Xf ,b.fytd1kc5dt9 j* z-linked recessive and not autosomal recessive?

  Different species of living organismso:a1aeq y)+an)s3 2g 7spmlb p have different numbers of genes characteristic to them. The table shows the estimated number ofea1 +37mn:bagoyp sslq)a 2)p 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 characayu65kek6 :7lu)m kk)lcte/ fteristics of pea plants, including flower colour. If the pea plants Mendel was studying can only be white or purple and follow the rules of Mendelian geneticse/ ukc )amlk6ty7u6k5): lkf e, which of these statements was correct?

  A biological male with hemophilia /lkxvq i6y)4*f)ougj7e 9w a qand a biological female without hemophilia have a daughter without hemophilia. What are th7 qjka4 lxo u*ewgvif69qy)/)e possible genotypes of the daughter?

  A dihybrid cross was carried out biywi+d+qq,f tv8 *(mw etween two sunflower plants (Helianthus annuus) to see if the gf( ,w*+iyqmd v+qi w8tenes 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 blood type A and fwan v4 7ety*8blood type B can have a child with blood type O. wfe48ayn v7t *

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

3.Explain the role of inheritance in genetic diseases.