A man and a woman have a daughter and a hen3w-cl. rq;son. Their daughter has normal vision, but their son is colourblind. Which one of these genotypes could be correct for the biologicarwq-en;.c h l3l mother?

  Which diagram shows the sex chromosomes of a somatic cell in )mw8du8 a+s;kn ievu(a human male?

  There are two alleles for flower colour in snapdragons. However, the result twb/:e p,*t ed*cpar, of a cross between two heterozygous plants yielded offspring with tpbe, *c/deap t :t*r,whree different observed phenotypes, red, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to the correcj5y:k y /f1hli1 1nonmt definition?

  Which of these statements is a cu6-h+ qv1aq eqorrect definition for a gene?

  The diagram shows a pair of homo/+6 vvxxkbb.h nst+n)by;2dd logous chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were crossed4ldou fdj20- v,har9x()t i/utwumk( in an experiment. Which0uw)ifrt94dvmathd, 2u(-jxkl/u o ( row shows the expected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agoqdj hbu502 9l i(u:gktuti allele causes individual hairs to have a banded pattern. The non-agouti allele causes hairs tqjuu(l5d b2tgki 09h: o 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 qk5 m/t 4x 0u)zqdm axt1w7oi3plants was either round or wrinkled. The results of an experimental cross yielded 315 offspring with round seeds and 105 offspringdwt0 uxzm1xk i 5t73)qaq4mo/ with wrinkled seeds.

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

  Neurons of the fruit fly (Drosophila melanogaster)bd 1bkkcv78g 6l;,bfw have 8 chromosomes. How many ;k,bd8v l7bbkw1fgc6 chromosomes are in a fertilised oocyte of a fruit fly?

  When does the random ozjn c*x*1vly (zum*9;qr71b+ wfv uyx rientation of homologous chromosome pairs occur?

The majority of the genes in the human genome have alblel-4dvkp6l uv5- + dw :t:nda:tec/ *gi- zjready been mapped, meaning the exact locations of the genes on chromosomes are known. Thece/l -ad 4vntw:tljvzl6:gbe-: 5ik-d*+pd u 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 correcte h80*-cpmot5oq 5n zs definition of linked genes?

  The diagram shows a karyogram of a brown male 9k ,f1k0;ae w (,lc xn2efynnprat (Rattus norvegicus). Which arrow is pointing to a pair fw pc,01n l knkx,an9(; ef2yeof autosomes?

  Mendel observed that there are two possible variations ,p( ob*aan5kyof flower colour in pea plants, purpleo5a a(,ypb nk* and white. After a genetic cross, the ratio of plants with purple flowers to white flowers is 1:1. What were the genotypes of the parents?

  The graph shows the frequen 6/5p5o 9dc) r s7/yatvwiyamjcy of birth weight of children born in London in 1991.a9 /dpjor/it6sy 5 ywcma7)5 v

  Which of these traits is an example of continuoc* mxyczfu c (h-b 4a9kmw*1/dus variation?

  Which row correctly describes o.1h4 q kl/ahydiploid and haploid cells in humans?

  The following table shows the diploid chromosobo 1+izj /jcb 0868;gyiag cjjme number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessiveshvg h5(f,5y, atu3lh 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 a child with zibx82d 0fx;ublood type O. What are the possible b0df2xx8 izu ;genotypes of the biological father?

  Which row shows the correct annotation of the alleles for yod fc7f -c;/ooeldb;6 d1u+cblood groups?

  Which of these statements are true forxxxk.4bcp h6 da2(pl6ejfpkcl5 s-+ 0 alleles?
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 incidqtg+/x np9l-n tun05q ence of sickle cell anaemia and the spread of malaria across the continent of 0lxq5/u -+nqtnpg n9tAfrica.


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 przewalski taync/y jdza .x1k7ly69wd6s;0 h v,h sh2r0di), fur colour is determined by a number of genes. Brown colour (B) is domin9h/00s.2l7dy1 dhcaw y a6;6, rnydvxshj tzkant 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 linkeesm zo,6 n -yfjjj5tkpdj 4 1v05h*ux8d and unlinked genes.

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

Sickle cell anaemia is caused byf,.mn vz)ric) 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 homozygous for broo-n8zqbjx vw;kjz4 2*wn, long hair and a female ca*w2 k8bzj- qv4jx nz;ot that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for dii;; 3shx jyw6smrv;f*amond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) is dominant over short seeds wss;i ;6j;fm * y3xvrh(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 a8j.s 2l 3zl8wrm8:xzug1hxueuk,n 3(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 hezgn 8.xj8ualh8:e, k2 muws3xzlr 13 uterozygous 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 inherita6*m ozgl x.ohf fm9w0z c+f*(qnce of the condition shown in the pedigree chart belof*ofm6o ( wz0xl.g+*qh9zfm cw?

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

  Which of these statements about genetic disorders is/are ct k ne:(i(6cunorrect?

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 normalo;e)9na1jbe bha nb.*cxfs5+o*zep, 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 disorder shown in the pedigree chart i z/: ej ;5y2o(-(l.7deo xziqwkj ypfos X-linked recessive and not autosomjozf5/e(:d .w-jiqok(px e;yy7o2l zal recessive?

  Different species of living organisms have different numbers of gene+73ib;b9 h4 pz4fa.kty wd babou03 sas characteristic to them. The table shows the estimated number of genes for five species.i 7d0hbwab+u3a f;to p34byz9a4bk .s
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 rfb,h0i0 yo;e/nnekocd9n0 b3+n3 d)z0 jrdapea plants, including flower colour. If the pea plants Mendel was studying can only be white or purple and follow the rules of Mendelian genetics, which of the)n0 o0hz+no/adcrrfni0;9bd n 0e3kj y ,bed3se statements was correct?

  A biological male with hemophilia and a biological female without hel 08di+c6kil)smo(m t-i1byemophilia have a daughter without hemophilia. What are the possible geno im(i)y+8b eo il 6k0smc1tl-dtypes of the daughter?

  A dihybrid cross was carried out between two sunflower plants (Helianthus annuqh9 f6h7 /ka4wfl r0wv5 lasl;us) 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 calculated vaw k 4 s9va7/hrqlal0hfw6f;5llue for the chi-squared test was 10.05; what does this indicate?

1.Explain how parents with blood type A and blood tyo./vfxqx*k* i pe B can have a child with blood *x/ v*xoki.q ftype O.

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

3.Explain the role of inheritance in genetic diseases.