A man and a woman have a daughter and a son. Their daughter has norm3,/iuda fz3: u,mmorkal vision, but their son is colourblind. Which one of these genotypes could be correct for the bd3: iuamu/or,k,3fz miological mother?

  Which diagram shows the sex chromosklhcabls i,)q5a - 1d0omes of a somatic cell in a human male?

  There are two alleles for flower colour in sna9k e7dn48nrvl( a8v zfpdragons. However, the result of a cross between two heterozygous planvl z 9kdref4v8a( 78nnts 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 correct, 5*0( kr c;todetg/o27-ms kvzx qbyz definition?

  Which of these statemeoi 7-p07j myrj obf3,vnts is a correct definition for a gene?

  The diagram shows a pair of homour,ozv:d(a5 q4 zove7 logous chromosomes.

How many loci are shown?

  Two individuals, heterov0; pllze10ni zygous for a specific trait, were crossed in an experiment. Which row shows the expected phenotypic ratlp01;e livn 0zios of the offspring resulting from this cross?

  In some animals, the agouti alle((h2jpsl c tt6le causes individual hairs to have a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who aj sl(2phttc(6re 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 individua;6t vx)i/ s;*ocrpgj (manl( p4xjdzlqa5q , 9l pea plants was either round or wrinkled. The results of an experimental cross yielded 315 offspring with round seeds and 105 offspring with wtclpj gp)v 95od/,;xaszq6m ;(lix(r4an* j qrinkled seeds.

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

  Neurons of the fruit fly (Dror fobggkc1 cg.- f9g3; 1pd4ayz1ia z5sophila melanogaster) have 8 chromosomes. How many chromosomeocp-5g1c1a.z;3fz bgg if1 rg kd4a9ys are in a fertilised oocyte of a fruit fly?

  When does the random orl o)q e;(s4(htv;nnm2tpm 7pylk9s e+ientation of homologous chromosome pairs occur?

The majority of the genes in the hujhfq n6.k+q lp o,r67oqt/-dbman genome have already been mapped, meaning the exact locations of the genes oqhbkl- qn 6,r otoj. q6dp+7/fn 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 oeu(9 a:yxzb3lp x5d38;wtkrgenes?

  The diagram shows a karyogram oey(pi w3,k :2ux.ue5 m7eu/o snf.fbw f a brown male rat (Rattus norvegicus). Which arrow is pointing to a pair of a,ww7./use uo.3b mffpyx :(5ene2iu kutosomes?

  Mendel observed that theri mpefoonw(+6s*0w4 t.yeg: ne 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 theeey6t ow0i(+nng. * w:f 4spmo genotypes of the parents?

  The graph shows the frequency of birth weight of children born indi i0l.)*t8kyc:slz i London in 1991.s tkdl8iz 0):lci* i.y

  Which of these traits is an example(jg c*,2wnm9sixb : r *sooiw1 of continuous variation?

  Which row correctly describ;o:s3:ypul nies diploid and haploid cells in humans?

  The following table shows7s+af :-xw7qpq guj w9 the diploid chromosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive allele (Hoy,xres nwe5i)m 8/ -lb$^S$). 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 had5: bd+;u:c*cv weji2sp iku0e a child with blood type O. What are the possible genoty;cepecidu0 :u5 i*k+:2jbws vpes of the biological father?

  Which row shows the correct annotation of the alleles for blood k vmicaj30.ql1+gve 6 groups?

  Which of these statements are true for alz6ikw ho-cu cqy+4a 50leles?
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 maw;pd;q:4 fd kuuds 61b3 z6mchlaria across the continent of Afb;u muz6d cfd s614:;p kwhd3qrica.


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 soo 8bgvw.s */is determined by a number of genes. Brown colour (B) is dominant to sandy colour/osb w.vgo*8s (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 unlinked genes. a1du:f(w i+;kr9ac i. ja/fba

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

Sickle cell anaemia isw i .v nav9l8hyg7/2zl 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 a cros k wrj ll/uojvo9k(-e40gon 3-s between a male cat that is homozygous for brown, long hair and a female cat that has black, short hair. lgo4rej n9 3u0( v/owkkl-o-j


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamond-shapehdgdxd94)b jad3yu + 1d seeds (D) is dominantdx4 dd3dgb 1+j)hu 9ya 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),j1m 69g 9vq.lm rxp-ix long hair (L) is dominant to short hair (l), and curly hair (C) is dominant to straight hair (c). A test cross was carried out between male het-v1mmqx ri6jgl 9.9x perozygous 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 shown qh 1fcwh9,uu*hvk (d8m(9qqa 0;avmiin the pedigree charthu *(i;fqc v90 m1aakquvh8h,9 qwdm ( below?

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

  Which of these statements about genw26hw-qbs+l0t xa p;vshg+x e5f(qx4etic 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 polygenn7j48ix . 4s-c6 (odx rrakstp7i/dnjic traits 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 disou/mbpb 9zjx )-vhi 83qrder shown in the pedigree chart isb83pj /- h i9uqmzv)bx X-linked recessive and not autosomal recessive?

  Different species of living organisms have diqarwo d55n43sd:z+xd-t9sp47cfopf fferent numbers of genes characteristic to them. Toos :ar-fcsp dt 5qpwn49d3+5 z4 fxd7he table shows the estimated number 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 plants, including flower g t7j-/1fqthecolour. If the pea plants Mendel was studying can onlyf1jt 7 /q-hetg be 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 withe/ti uxs a/9j ph6*fn-out hemophilia have a daughter without6x*/tpfeiu s-hj / n9a hemophilia. What are the possible genotypes of the daughter?

  A dihybrid cross was carried out between twp,49i 2a(5e lb e5 fqb87apjxmuum(ico 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.p(5uabjxm e27 iup5ea(i ,4clq8f 9bm05 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 typ*0fk2i mk.9:z hpbpjcou 12wke A and blood type B can have a child with blood type O. *fuk.:2 cj 29m pbwipk0zh1 ko

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

3.Explain the role of inheritance in genetic diseases.