A man and a woman have a daughter and apx0 ,l(upf0;f d3dbu ;gi9on 0ig,bks son. Their daughter has normal vision, but their son is colourblind. Which one of these genotypes couldbuo0gfpk gsb;ln;d, idi fp390,(ux 0 be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic cell in a human male; ybiay50y.h p?

  There are two alleles for flower colour in snapdragons. However, the result of 6p ekftri8 v q:0,w y5v0pv /k4flqx/fa cross between two heterozygous plants yielded offspring with three different observed phenotypes, red,fyq ,v5/ft4v qw k8/ki6 r0pvxp0efl: white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to the correct defin (y8mr *pznw7vuf7p3;m vw7miition?

  Which of these statements is a correct defini2.uh0uy xpt 0 (zy5szution for a gene?

  The diagram shows a pair of homolo6cx*gg 68k(av sxm ug-gous chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, werep:priw 2d m8kte*f1 c) crossed in an experiment. Which row shows the expected phenotypic ratios of 8* p)1wpe:2fmdri ckt the offspring resulting from this cross?

  In some animals, thetn s0y+68m * w85wcc.ov l)tl qpw*ubj agouti allele causes individual hairs to have a banded pattern. The non-agouti allele 0jwtm o5wbc*yw*+ c)svu.88qtll6 p ncauses 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 inf yqsh4u5 jv*w i-br p.6if.8ndividual pea plants was either round or wrinkled. The results of an experimental cross yielded 315 offspring with round seeds and 105 offspring with wrinkled .j yipqf5 6-bnfri.h*w 4s8u vseeds.

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

  Neurons of the fruit fly (Drosophila melanogaster) have 8 chromosomes. Hcku a8s./b q m-1ni/syow many chromosomes are in au8i k-c/. msqsab/1n y fertilised oocyte of a fruit fly?

  When does the random orientation of homologous chromosome p lg.afm-6l na5airs occur?

The majority of the genes in the human genome have already bee0up-izjqw4 )x5t8c ic **bsi cn mapped, meaning the exact locations of tcui4c0 b 5*cijtw)8 xi* zq-sphe genes on 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 x(pgi1j 258( btdf hma bu2ds+fy,;6mmt9o gzlinked genes?

  The diagram shows a karyogram of a brown male rat (Rat29ysb akr :.e cbb-8zttus norvegicus). Which arrow is pointing to a pair of autosomet98z a-2b cysrk:b. ebs?

  Mendel observed that there are two possible variations of flower colour i+px + c2eh2eean 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 ofeec2 h2 ax++pe the parents?

  The graph shows the frequency of birth weight o8;hg oeot*xs 8f children born in London in 1991.x*s;eoo 8h gt8

  Which of these traits is ala iaq9+9o+vz2ck 892hdwfozn example of continuous variation?

  Which row correctly describe2kx f.s2 o/jhxs diploid and haploid cells in humans?

  The following table shows the diploid chromosome number of a range of specielgah 9f2*/w ljs.

Which of these statements is correct?

  Sickle cell anaemia is causqwgbqv1 v:.6kkwc;fq3 sv; 7 sed by a recessive 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 typgvwrfdg+ 8+o(e A had a child with blood type O. What are the possiblef+(d gogrw+8 v genotypes of the biological father?

  Which row shows the correct klc3 p1w4nb*c q,se3 0tc4nax k0l;aq annotation of the alleles for blood groups?

  Which of these statement j:)66do:y4x+ineeix f+a e hks are true for 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 incidence of sickld u6rdv(e(uox qxd(6 u:6j8 twe cell anaemia and the spread of malaria acrxw(66(e vtdu 6x: d (rd8ujqouoss the continent 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 daj *t9xb+5rng etermined by a number of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two r*jxba5g 9t n+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 betweenxxca6 sky2o mk2+e)i+ linked and unlinked genes.

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

Sickle cell anaemia is caused by themm, ut3pfd +t.t5pwqtg+ x18k 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 betweeh a v8hzsj-t4 zf,7hc(n a male cat that is homozygous for brown, long hair and a female cat that has black, szj t,cf4sa(h7v8 h-h zhort hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for dg 4,n1 yh, x5ga.shw--m4:ezktbcytpiamond-shaped seeds (D) is dominant over oval-sk-.pxm 5:4ys gn 4 1zh bgetwc,t,yah-haped 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), ,ajf h;e 3bs,tf-0.njkq6xyplong hair (L) is dominant to short hair (l), and curly hair (C) is dominant to straight hair (c). A test cross was carrie n q;ka ,,jf ybe6ht.3fsjx-0pd 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 inbv p *1wy/zqh)xu mzj/vbk()( the pedigree chart bex wkv*(hmq()zp bu zjbvy/1/) low?

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

  Which of these statements abouth3 e1zan)pt; oa4, u3tn dvbo0 genetic 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 polygenic traits can sho9ssj9 p2:l4q/fi sr fzw 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 theuf9bf ,;r4ui:v4x xyfm+raw ) pedigree chart is X-linked recessive and not autosomal recessiwu9ivfxf4:b x;)a,rmr+fuy 4ve?

  Different species of living organisms have different numbers3-r ar ;lqc7z,2yiqb n*ts1ul e/x+gh of genes characteristic to them. The table shows the estimated number of genes for fivi cqr+a3/;e 1yqgn7 2usxl,z thlbr -*e 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 che 30(i9uq jzc4-h ubwmaracteristics of pea plants, including flower colour. If the pea plants Mendel was studying can only be white or purple and follow the rules of Mendelian genetics, whichi9 u03z bjm-h4cqe(uw of these statements was correct?

  A biological male with hemophilia and a biological female without hemox10lp iwcn-n7npqb7.-mn5 t yphilia have a daughter without hemophilia. What are the possible genotypes of the dac--5nbp7m 7nx10q niytl .np wughter?

  A dihybrid cross was carried out between two sunflower plants (Helianthus an2 wq 5lmhjc,7 ujd jmw4c3hk0kd j3:t)nuus) to see if the genes for seed number and seed shape are linked. The critical value for tmj jw)mju5cdd 0,kj4c3lhhtq w7k: 32he 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 typeg;sajlv*4 s+ w B can have a child with blood ty4*gwls aj +;vspe O.

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

3.Explain the role of inheritance in genetic diseases.