A man and a woman have a daughtek5 mt.a8bp( h z5poc6mr and a son. Their daughter has normal vision, but their son is colourblind. Which one of these genotypes could be correct for the biological mothz ac bmpmkt.(p6h85o 5er?

  Which diagram shows the sex chromosomes of a i s,h5molv7g xzm8) n v+-mvs:somatic cell in a human male?

  There are two alleles for flower colour in snapd/wei14 rz24a viha7g9kxh6u tragons. However, the result of a cross between two heterozygous plants yielded z72u k v4r9ghw1iae/6ati 4 hxoffspring with three different observed phenotypes, red, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to the correct def rg 6e22n22 uoh0,vj trmokhu:jp5:iqinition?

  Which of these statements is a correct definition for a tk4y w80;k13 wxc(lxuges3a j gene?

  The diagram shows a pair of homologous chromosomes;8 sslbsm(wx1 .

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were cros-1 -r1d-thc sbt,u8a- sv bzrfsed in an experiment. Which row showsub-t zss8-1hrvt f1ac rdb--, the expected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti allele causes individual hairs to have a bandq5fpk3 oeg 0x3ed pattern. The non-agouti allele causes hf0q5xk3 p3oegairs 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 wa )rwt5x u7so6gs either round or wrinkled. The results of an experimental cross yielded 315 offspring with roundr)6sgo7t w5 xu 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 mk3( uhmhp9s)5 wnxld8 elanogaster) have 8 chromosomes. How many chromosomes are in a nx p)9sdwl5u83hkm(hfertilised oocyte of a fruit fly?

  When does the random orxme ,b6t8ra6a+nkz o:n1 so w,u;cdx 8ientation of homologous chromosome pairs occur?

The majority of the genes in the human genome have already be/azc:oo ldwfd9o-e,u-j m(i,en mapped, meaning the exact locations of the genes on chromosomes are known. The diagram 9fidw,/ o(:a -du,o lezomjc-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 definiti m6 lcd7ub6rp(q c,io jpt1(g5on of linked genes?

  The diagram shows a karyogram of a brown male rat (Rattus n)r66b fo f; g oh1ow7w z;v65.frypdasorvegicus). Which arrow o6;y po)ag 76ff rdbvhw .16wz;f5soris pointing to a pair of autosomes?

  Mendel observed that there are two pqfz x3-doa7l;dr5-jg ossible variations of 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. Whaz3d lfqrog-xd ;j7 a5-t were the genotypes of the parents?

  The graph shows the frequenxk3qw3ou :cr/ 5a+q tncy of birth weight of children born in London in 1991q5 k 3t3+qcaxownur:/.

  Which of these traits is an example of continuous variatitl-n xpe52 4. mrrbe ylm8oo55on?

  Which row correctly describ)uo90m frqjw0)n mmz( es diploid and haploid cells in humans?

  The following table shows the diploid chromosome nk1yq( ;lt1ldw :y;:f3jew z zuumber of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive allkfl.:7 tcdbyo+t7o+ eele (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 blood type O. What a-f8owwij;ur/jn f5/ xre the possible genotypexuwj//5ow- n fjf;8irs of the biological father?

  Which row shows the correct annot, ;qnx jdw)o2yj4 zkh*ation of the alleles for blood groups?

  Which of these statements are tk)c n8nkfhdnrd-4 (.-uy*+gbmp, rlv rue 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 cell726wwrwqb1 p ko q5g)o anaemia and the spread of malaria across the continent of Africa.q51 w76)op wrbqwgk 2o


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 iltg;-0ybm :e wgp3 :gos determined by a number of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) me ;-ogylgg :30w t:pbcolour (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 linw subr6;ln1+dtk k* d9ked and unlinked genes.

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

Sickle cell anaemia is o;1omt8 zhc7,mfkj g- caused by 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 brownp s4a z nov+)czhn*)r*, long hair and zr)hn4np*oc sv*z+a ) a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allelek hw;j*;1juk v for diamond-shaped seeds (D) is dominant ovej;k w;u 1vh*jkr oval-shaped 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), long h3xsyo9l3v g*f8f5ff ekbz j ,7air (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 heterozygous long, curly-haired guinea pigs and female short, straight-haired guinea pigs and a chi-squared test (χ2) was carried outbf7 ej 9lo,kz *g533fsxf8yfv 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 in the pedigreh:zwmm r9; 6oxe chart belowxhm9;z6: r wmo?

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

  Which of these statements about genetic disorders is/ndq5zp4v +k, yrz3y c2are 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 thyfqs) oga2 kv16n z j:12 3fcpwd53tvraits can 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 inh h7qy ctnfav:. )-z( y9rf) h:i1jdgaqeritance of the disorder shown in the pedigree chart is X-linked recessive and not aut.9 ghq1q:r(j-v)i d)at7zy afyhf :cnosomal recessive?

  Different species of living organismsb- wsy di5px/2zn r5:t have different numbers of genes characteristic to them. spwtin dx/5: y2r-5bz 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 charactegkgtp,4pbs u-54 lf6 fristics of pea plants, including flower colour. If the pea plants Mendel was studying can only be whig64tfs5b4,ppl fu g-kte or purple and follow the rules of Mendelian genetics, which of these statements was correct?

  A biological male with hemophyrz6d3opsr tp4e4t:h io:be(+/* j htilia and a biological female without hemophilia have a daughter without hemophilia. What are the possible genotypeb rp/pr36o(ds*ete:toi4:4tjhzy h + s of the daughter?

  A dihybrid cross was carried out between two sunflower plants (Hel ix3t6m.wmcj 0cj4fh 1snorn28- f1uaianthus 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 calculated value for the chi-squared test was 10.05; what does this indis.4 x18ru6c wi m2fjo0fjmn han-c3t1cate?

1.Explain how parents with blood type A and blood type B can 0xfp6 ivc2j4 mhave a child with blood typ p j4cxm2i6vf0e O.

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

3.Explain the role of inheritance in genetic diseases.