A man and a woman have a daughter and a son. Thei5up z6:gj +4a:xofwiur daughter has normal vision, but their son is colourblind. Which one of these genotypes could be correct for thupuz wx::go +6i5a jf4e biological mother?

  Which diagram shows the sex chromosomes of a somatic cell in a hum)to 3 ajt,ix0ian male?

  There are two alleles for flower colour in snaexgig b(umclcf598cf -3)a1d pdragons. However, the result of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red, white and pink flowers. Whichcm9 51f-3fcgu 8cxg eiab(l) d is the most likely explanation for this observation?

  Which keyword is matched to the correct definif /t+,hpr/g -dkd ,whbtion?

  Which of these statements is a correct dp, fxj wfl+2i6efinition for a gene?

  The diagram shows a pair of homologous chrhr)m-mk7r5 sromosomes.

How many loci are shown?

  Two individuals, heterozy k5,rd90fyi;o5lkbda gous for a specific trait, were crossed in an experimentf, i95d;rb0 5dkaokyl. Which row shows the expected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti alleq3 9,ckc; )5+6x gmoo2m mx jiwpa;cttle causes individual hairs to have a banded pattern. The non-agouti allele causes hair95qtom+j3ck ;x)xop6t cmw ;m2i,ca gs 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 individua g )1v+oy3c(slm:no/l whq 6,m)s proml pea plants was either round or wrinkled. The results of an experimental lo:,r hm/ vwm)(q nos)+1m3os yl g6cpcross 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 chr:yh4n,o/0 kht: obob somosomes. How many chromosomes are4: tybo bno/h:hk,o0s in a fertilised oocyte of a fruit fly?

  When does the random o.yda 0z2ffyp 3rientation of homologous chromosome pairs occur?

The majority of the genes in the human genome hav:p r,kp.wxhn1 -9 ei tddre:8he already been mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one representation of a homolog1rh dikxr9h de. pwe8:np,:t-ous 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 correctshnlpxb2 5el;b6 :4um definition of linked genes?

  The diagram shows a karyogram of x: g7iko*bc o0a brown male rat (Rattus norvegicus). Which arrow is pointing ti7 b *ogcokx:0o a pair of autosomes?

  Mendel observed that there are two possible va9cwhvv5k3t35m8mnd vc;tr6zriations of flower colour in pea plants, purple and white. After a genetic cross, the ratio of plants w ctw8dr v9tz;55m6 3khmv3cn vith purple flowers to white flowers is 1:1. What were the genotypes of the parents?

  The graph shows the frequency of birth weighib.t8 v19tuqpt of children born in London in 1991. q9 tubiv1. 8tp

  Which of these traits is an exambhq0(ks0qp- -y w6c zfple of continuous variation?

  Which row correctly describes diploid and haploid cells in humans? x6 eeqp6qxqaa9c,7r7gz 6 bk/

  The following table shows the diploid chromosome number ov x a5pg xie h8qjodv;z,(1.r*f a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by le/th0al5 5tb- r/nqy 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 wi kq)6zns urv tuhwc+*/1u-a9s th blood type A had a child with blood type O. What are the possible genotypes of the /-nrkhw+ a9*6cuzq 1svs u)tu biological father?

  Which row shows the correct annotatg4-c0q- :jli4 po uwreion of the alleles for blood groups?

  Which of these statements ara40f96,8cmn3iicr 874acd )z jdd 9 udpzqmtce 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 sickle cell anaemias y2 1ssw-ro9w and the spread of malaria across the continent of Africa. w2ss-r91osy w


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 determined by a rcqzle85(7ey number of genes. Brown colour (B) is dominant to sandy colour (b) and aqrz5e(8ly e7c n 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 betweent- )vczif8m)rx izwb b8cv46 . linked and unlinked genes.

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

Sickle cell anaemia is caused by tx8 bt uz c h c:dfx-ufe:8gm(++so:xpe0a8 *obhe 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 homozvt xt,jm84 kh7y0( yumygous for brown, lokh mjyx08m,tvuy7t 4( ng hair and a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele ft- tva-b-5hwqor diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L)h-w-q5 battv- 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) is*f)unruswv ju kw/m d;9 6-hn- dominant to short hair (l), and curly hair (C) is dominant to straight hair (c). A test cross was carriev u nsndh-mu fr);w/j69ku* -wd 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 inherit6o: bht- h x61dmtqst)ance of the condition shown in the pedigree chart below? :s hth61modt6)qb- xt

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

  Which of these statementcvfa(su c+a* , yyt5r+s about 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 canh 53 myr1vwy*i 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 inheritvn 3zlv tvt/a+zk0yk4 30ntl:ance of the disorder shown in the pedigree chart is X-linked recessive and not autosomal recessiv 3a/kynvzz0 v+tvnt: tk30 ll4e?

  Different species of living orga3u60kuvp9 i bonefn95 5auu68 d*vvugnisms have different numbers of genes characteristic to them. The table shows the estimated number of genes for f3k vfnovb8e 09n i56p*a6 u59uguduvuive 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 j*pfdf8e es(t9c)(0m; m5u ame6 dqavcharacteristics 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, which of these statements ca*a60mp;sm(ueqtmd ) vje9 d f(e5f8 was correct?

  A biological male with hemophili3 yijd4 9bxm,qgdy7lkmzv7 m2. mo30ga and a biological female without hemophilia have a daughter without hemophilia. What are the possible genotypes of the daugh m2d 0m9io.g33g,kz7bxqyd7y lm4jvm ter?

  A dihybrid cross was carried out between two sunflower plants (Helianthorp7)pup8v8p( lc*chus 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 sign(8* pcl8pvpp )h7r cuoificance 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 e7*0zk+vipcwa(-7 .. p cj0iesef legve a child with blood type O. f+ci7pel0ie7ckv-(.eega j 0psw *. z

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

3.Explain the role of inheritance in genetic diseases.