A man and a woman have a daughter q x+,opqqe-:j3zsp 9vand a son. Their daughter has normal vision, but their son is colourblind. Which one of these genotypqxoqeqv, +ps: zj-p93es could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic cell in a human male?60dphfe.mm - hnh 9/cj95zxwg

  There are two alleles for flower colour in snapdragons. However, the res .k,f 1vvbb2nsult of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red, w2nk1 .b,vbs vfhite and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to themwn wy.lx7y2j+w(- hi correct definition?

  Which of these statements is a corrm +s z3r ew.eo vqhpt8:d)(y+vm 4fus)+2 abdsect definition for a gene?

  The diagram shows a pair of homologous chromosome/k( o fj1v1lxkwd 5*bhn(-j3gctssc ,s.

How many loci are shown?

  Two individuals, heterozygous for a specific tr(d71 nodn: q3kv+cdkxait, were crossed in an experiment. Whic 3v(:xk1no7d nc+ddqkh row shows the expected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti allele causes indiviss.ia l(-5onlql (ahbla/v.sm*,s * ndual hairs to have a banded pattern. The non-agouti alb.(os (5-lalsa ,* /lnalmi.sqh vs*nlele 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 plants was eith597sybh;;abkqbq0kdl5 xo l9 er round or wrinkled. The results of an experimental cross yielded 3 k099kx b l;qyqbb 5hdol57s;a15 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. How n+o;p8e++th0,w8a xcci q ud3d sctj +many chromosomes are in a fertilised oocytsthied8w+d,q npc x ; 3ou++cat +c80je of a fruit fly?

  When does the random orientation ofq)ch7 ; t9h-dt+k nahu homologous chromosome pairs occur?

The majority of the genes in the human genome hav o/ mn+udar39iph x*;-tmrhz 5e already been mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one representation of a homologous 9/h da+*5 mt upxh ;o-mrzrn3ipair 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 oa bnd+4 7w7nklinked genes?

  The diagram shows a karyogram of a brown male rat (Rattus noh-rn;zq2 nq2a7/ pr- rubyrf-rvegicus). Which arrow is pointing to a2hq-2-nz y-r/n rqbra7pu; fr pair of autosomes?

  Mendel observed that there are two possible variations of flower cov 9cbcy; mj. mkbae42df;*k6 qlour in pea plants, purple and white. After a genetic cross, the ratq ;km64d a.jbfvc9c mkey b*;2io of plants with purple flowers to white flowers is 1:1. What were the genotypes of the parents?

  The graph shows the frejvlnf u8i d+(n /im7)yquency of birth weight of children born in London in 1991yim7(v+j/nl fui n8d).

  Which of these traits is an example of continuous variation?* l :wbqm,9,jun-daof

  Which row correctly describes diploid and haploid ce06edi n (fj r **sg-q5wu: icewvhof32lls in humans?

  The following table shows the diploid chv p e5zrwj3-6kvg3m,xromosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a icd/n6 l/mqx8ivg96precessive 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 wp ukkv0;v ze5dvj+i3- ith blood type O. What are the3vkj ;-ez+k5vu0d pvi possible genotypes of the biological father?

  Which row shows the cs zyor)-m zc3s0eh0w 7orrect annotation of the alleles for blood groups?

  Which of these statements are true for alleler l79dgpvq 9 :il ,8l3ryr nii)7(sypxs?
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 incide ;.0wleuljk 4ynce of sickle cell anaemia and the spread of malaria across the conti j.yu;el40lwk nent 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), fur colour is determinef(ih1d vqqp9jq4s 0v3pkq / t6d by a number of genes. Browt0kv(j hqdvq3pfq 614q /9sipn 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 le 2qwxnpc+z8 e27run 0gm/ ,* 8irkvgwinked and unlinked genes.

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

Sickle cell anaemia is caused by the ez2b g o98wpxc+m58vfallele 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) lh,:)f-q+v rr(;cegmir* w si6avdl male cat that is homozygous for brown, long hair and a female cat that has black, sho wrv(r *:fq),mld+cah isg6r ei-v);lrt hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxdnr; 4k ndp nlmqi(7w10w;q ,iacum officinale), the allele for diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) is dominant over short seeds (l).dn;,m0(di nwrnwpq q4;7 l 1ik

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 porcel;1x d:uq e1wenfq;2jclus), long hair (L) is dominant to short hair (l), and curly hair (C) is dominant to straight hair (c). A teednw:q ;qe2c jx1u;f1st 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 conditionvq:v9mk7vz8 ;rp -62tfdy nul shown in the pedigree chartt;6d7-mfknvp82:9lu rv v qyz below?

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

  Which of these statements about genetic disorders is/are coo, eh itfgl,50+h s3o4ycj n5mrrect?

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 ca q-pduhr,(z/ep8 j9k of1l bj ,ozi9wfuu(7o8n 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 disorder shown in the b94 n;(tz :ua sezxxq.pedigree chart is X-linked recessive a:x ze.s; bx(uz9tan q4nd not autosomal recessive?

  Different species of living organisms have different numbers of . i0 e r*n9k(+-hcjc ji+zbwwogenes characteristic to them.o(j hi *cbjw ecn k++0r.iwz-9 The 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 yb3thr s5in/s2.w o/xcharacteristics of pea plants, including flower colour. If the peo nb/ws/h2t3xr5. isya plants Mendel was 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 biological female withouvvup . 5j7lp aewt(*.wt hemophilia have a daughter without hemophilia. What wvt7wejuapl..v *5(p are the possible genotypes of the daughter?

  A dihybrid cross was carried out uvkflnexeq1/r,* p+9 between two sunflower plants (Helianthus annuus) to see if the genes for seed number and seed shape are linkrq/,lvnu91xpkf*+e e ed. 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 blood type B can have a child p*5gnf .:x qbozx)jy2with blooz:xpnoqg2 y5fb*. j )xd type O.

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

3.Explain the role of inheritance in genetic diseases.