A man and a woman have a daughter and a7l/n( hcnb b(o son. Their daughter has normal vision, but their son is colourblind. Which on l(n7(/bhbcone of these genotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic cell ink :)t3 bi5v5d 4hyrvd0(hsnak a human male?

  There are two alleles for flower colour in snapdragons. However, the result of2xlp4r)azvg1 -c h 7vy a cross between two heterozygous plants yielded offspring with three different olcg zx1-a7vy) v2hp r4bserved phenotypes, red, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to the correct definition, g8sdwsfwkc1d j93(l ?

  Which of these statements is a correcttw9gdo7 4(7sb ,iee 03ryvngy definition for a gene?

  The diagram shows a pair of homologous chromoso34-afsxf(cu s, g vj;fld9:/n zh2w6 +q ezjnemes.

How many loci are shown?

  Two individuals, heterozygous for a specific trzppva1y 06 m)aait, were crossed in an experiment. Which row shows thz pyma 0)p16vae expected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti al8wh ythc*n/e9/ tbp sn:)isd2lele causes individual hairs to have a banded pattern. The non-agouti allele causes hairs to :)w* eh/ hdtiyc2ntb8s /9spn 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 inq8 meetad (3t* individual pea plants was either round or wrinkled. The results of an* tte8q dea3(m 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 (Drosophila me0ryzvnc o( 9x+lanogaster) have 8 chromosomes. How many chx( oynz0v r+9cromosomes are in a fertilised oocyte of a fruit fly?

  When does the random orientation of homologous chromosome pairs occur p, :fdefu jagqhi8.8;?

The majority of the gene qop9c ht1lcpk/.4 qp,s in the human 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 chromosompl14qc9/o qp,k.h ptc es.

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 lin fhew(*ev0vy:1e vju28b 5 ondked genes?

  The diagram shows a karyogram of a brown male rat (Rattus norvegicux+x8wxg+jpp * fn)xe2 n)j)s qs). Which arrow is pointing to a pair of a)xj8 + qe nxx2jp)wxgs*p+f )nutosomes?

  Mendel observed that there are two possible variations of flower colour in pea (zkv0pv2,*hzvm urbw 3 u7eq2plants, purple and white. After a genetic cross, the ratio of plants with purple flowers to white flowers is 1:1. What were the genotypes p kmruuzv (,e zh*wb2v3 0vq72of the parents?

  The graph shows the frequency of birth weight of children born in London in 1991 d;p3oic0tfzvr6k , i2 rf)*ky i6c;fy z)3*2fkv0,ikdt ropr.

  Which of these traits ism6-fcpk,x:3wnv p 9h b an example of continuous variation?

  Which row correctly describes rm(;og2 j+;vi)jlrd udiploid and haploid cells in humans?

  The following table shows the diploid chromosome number of coo. 2t8+iwema range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive allefheo0zc0m7m :6rnlh2 le (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. What)z z5nn d mcw7(1jizg) are the possible genotypes of the b m n)n5z7iw)1zdz(cgj iological father?

  Which row shows the correct annotation of the all4oyy./p ly-7 zfknyy5eles for blood groups?

  Which of these statements are true for azhz.h a ccv8jo b99+0tb84aivlleles?
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 ins9(d,*u vnb5 bm.xufccidence of sickle cell anaemia and the spread of malaria across the continent. cu n,svd f(xu*9mbb5 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), fy6k6ps gdx9 rz9 0wcg)ur colour is determined by a number of genes. Brown colorkcpzg9yw 6dg 6 )x09sur (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 betweenu*+vk s(hyb6m linked and unlinked genes.

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

Sickle cell anaemia is qjkdhsgnq;* uj-b 8(cu8; , hecaused 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 cross between a male cat that is homozygousqjjv6*, hv)-nky:lqw) :-awx yxfwc 4 for brown, long hair and a female cat w vn)yh a yf-4l 6xjvq:):q*- k,wxcjwthat has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamond-shap.nzo; d)ms:s .9rde0pe vvs v(ed seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) is dominant over ss) deozv;pemn srv.sv.:0d(9hort 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 porcellusd1j6al+g+cto p vrsvd :cl+78 ), long hair (L) is dominant to short hair (l), and curly hair (C) is dominant to s1 sclrtojv d8 c lp+76v+ga+:dtraight 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 condition shown in the,v,gg60ay9 ,wzg2pyvf-obrv pedigree chart fyz6bv-,2w vg,g0o vgpya9 ,rbelow?

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

  Which of these statements about genetic disorders is/are correfa oej-u)2adzyq 2 p5.ct?

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. no:.sdb) kr5n

2.Outline the differences and similarities between homologous chromosomes.

3.Explain why expected and observed Mendelian ratios may differ.

  What suggests that the inhe5(0qii6os g xlz8bgcqvaah .8 8w3 en)ritance of the disorder shown in the pedigree chart is X-linked recessis3(q 8g)elacz8bg n6 5.0 wix8ohaviqve and not autosomal recessive?

  Different species of living organisms have different numbers of genes cht* d9i+j37humka:bk maracteristic to them. The table shows the est+m3hk :9dki*7baujm timated 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, inc +1vx b*ud;bdvluding flower colour. If the pea plants Mendel was studying can only be white or purple and follow the rules of Mendelian geneticduvb+*xv; 1bd s, which of these statements was correct?

  A biological male with hemokr k-(hb a8)evphilia and a biological female without hemophilia have a daughter without hemophilia. What are the possible genotypes e )8k-habrk(vof the daughter?

  A dihybrid cross was ca3)aytxerb37 nf*l l*vkn +iw7rried out between 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 tes)v t3*73lyib eax*7lnrn+k fwt 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 blood type B can ha(n3 pg* ifoue7hx4:lmve a child with blp*ux3 i: 4l(nog mhef7ood type O.

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

3.Explain the role of inheritance in genetic diseases.