A man and a woman have a daughter an:: min;5 qtr(pjozy7vd a son. Their daughter has normal vision, but their son is colourblind. Which one of these genotypes could be correct for the biological mozip:jv:75qnot yr; m( ther?

  Which diagram shows the sexxaknp71 ,5x pq chromosomes of a somatic cell in a human male?

  There are two alleles for flower colour in snapdragons. However, thv8 wx-qb psw gn.25zbc+5whr-e result of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red, white and pink flowers. Which is the most like8 5. pcbww- +qn2hbs5w x-zrvgly explanation for this observation?

  Which keyword is matched to the correct dawbsprqx v .zff 9*jrq rk6ep*h1 0494efinition?

  Which of these statements is a corred7:7xlvhh+ .r, *( jf -lngl wc6nytihct definition for a gene?

  The diagram shows a pair of homologous chromosomesgx4x)ps2eyliqt -/z4 .

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were c lrh-aa7+ d,ud60ic8zxw , 63mx ahwtxrossed in an experiment. Which row shows the expected phenotypic ratios of the offspring resulw ,i8w xm+atx7adcz6l-ra,0uh3h dx 6 ting from this cross?

  In some animals, the agouti allele causes individual hairs to have a band hv: xoam1xt1xh4ln 4*ed pattern. The non-agouti allele causes hairs txnm 4xv4ht*lxh 1o: 1ao 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 indefu rd ek8tk71t2xzng8 +ab31 ividual pea plants was either round or wrinkled. The results of at1 zd283u+tx rkg nb8 e7kfae1n 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 melanogaster) have 8 chromosomes. ccg uo z2-h,d:How many chromosomes are in a feru,c2h-:do zcg tilised oocyte of a fruit fly?

  When does the random orientation of homologous clwtcz7fg/o3cm ;o 49x1o. 4a ivklon5hromosome pairs occur?

The majority of the genes in the human genome have already been mappeds5u7 kc 4 qzpoa1.oc8a, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one representation of a homologous pair of chromo1o745 pqzca8uko cas.somes.

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 ofo(lxr0yr- ow)1bbr9cn w9 hl i 2kuqu;cv 4q;7 linked genes?

  The diagram shows a ka zd7.dgj tquh(o6g 4m5 d/is(sryogram of a brown male rat (Rattus norvegicus). Which arrow is pointing to . mg 56qs4o hu/7sjd(giddzt(a pair of autosomes?

  Mendel observed that there are two possible variations o9b:s;nh c,todyu * 6pbomsg,5o ow;5s f 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 genotypes of the parents?;wbg ;u56t:sco9s, ,oyonpohs5b d *m

  The graph shows the frequency of birthfke;/b6 cu* lj weight of children born in London in 1991.lufk 6;bce/j*

  Which of these traits is an example of continuous van4bk2yb71,sd *pufkeriation?

  Which row correctly descjz4t i, rm)kn 6onh1w2ribes diploid and haploid cells in humans?

  The following table shows the diploid chromosome numbez f0q2*jof rah+w ;kl0r of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recesneh g :: 91f4ce4xv(euoxwa :hsive 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 chilvddmq)c)lr;3o om;vgj+s) * y d with blood type O. What are the possible genotypes of the biological fgrq oo)dvv3m) *s cj;dl);+y mather?

  Which row shows the correct annotation of the alleles ftg/7rc 2)qgzfk3 +zlyor blood groups?

  Which of these statements are true for al,pj2mbuo.n e6tns/jws( 4xq, leles?
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 inp22 ux3q.88mers quwxi,hg7r cidence of sickle cell anaemia and the spread of malaria across the continent of Africapg 3wxh,i q .m8 se2qurr872xu.


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 is determin5 u pnjb(yct4 pu hf-n3avy8x 4 kh-y8/f3e7bred by a number of genes. Browh4h/e pn3xv 845u yjfk-f b3 btyar87(-pyu ncn 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 linked and unlinked g;d kgql.yt8,-cyk t /senes.

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

Sickle cell anaemia is caused by the allym b a(,sia3f)ele 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 ,3;kj, d i4jh8nwlmivro 4i1 kfor brown, long hair and a fema4k4,j iw ;id18j,3 vnrihmlo kle cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum off osp+.3ec,stt icinale), the allele for diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the stso+,p 3etc.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), long hair (L) iqp / 7i5**c 6at6fnjv 2jgpb9hkg fr:hs dominant 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, strai* n29qk a 7cj6/rghfp6:bijgh vftp5* ght-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 inheritaw 3 sqvoy4a/wcdr0m9 9nce of the condition shown in the pedigree chart w oq9r s0vdw 3/m49cyabelow?

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

  Which of these statements about genetic disorders isfl6hqmj //z5u 6 wn-eu/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 normgou :.r)jza /zwe7f v-al 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 disp/z3q *k qz1anorder shown in the pedigree chart is X-linked recessive and nqza*/z 31pnkqot autosomal recessive?

  Different species of living organisms have different numbers of di 1 gj--5iu*u*yc kldgenes characteristic to them. The table show*g-dj i* u1-cukyd5lis 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, includ llx)+v8 7c f2syb +mtl;s3vdy 45smfning flower colour. If the pea plants Mendel wcml l 7+d;s 8n4vs+3lsx mvy b)t52ffyas studying can only be white or purple and follow the rules of Mendelian genetics, which of these statements was correct?

  A biological male with hemophilia and a biol5bau 5:,k1rolf .1 vibag8wozogical female without hemophilia have a daughter without hemophilia.o aa8 gr ,bo5.1w1 ku5vblzi:f What are the possible genotypes of the daughter?

  A dihybrid cross was carried out between two sunflower plants (Helianthuswfa, :;c, yhbr 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 calculat a,;brhf wc:,yed value for the chi-squared test was 10.05; what does this indicate?

1.Explain how parents with blood type A and b f/7l)*o ejg,ta iuwm(lood type B can have a child with blood oejw(il 7 / fmutg,a*)type O.

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

3.Explain the role of inheritance in genetic diseases.