A man and a woman have a2vuyo pcrcmlrp,.z8z o )41w: daughter and a son. Their daughter has normal vision, but their son is colourblind. Which one of these genotypes18cwr rl zm.) pu,v4yc o2z:op could be correct for the biological mother?

  Which diagram shows the ser7-ll6w*7uq v1n jj gjx chromosomes of a somatic cell in a human male?

  There are two alleles for fb/ 83iw3obnd tlower colour in snapdragons. However, the result of a cross between twoib3t38 no/w db heterozygous plants yielded offspring 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 corra ;9*t o(bee -kbl*qlbect definition?

  Which of these statements is md a )1yz2e-boa correct definition for a gene?

  The diagram shows a pair of homologouve/ miq ev :9li/6/joxs chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were uof59mwr-6 tp4t /tprdxy( v7crossed in an experiment. Which row shows the expected phenotypic ratios o(5 -rrtmpp dw 7v4o9t6fty/xuf the offspring resulting from this cross?

  In some animals, the agouti ally342lrwsvj b.m a6k c 1q.n/wns0pr -nele causes individual hairs to have a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who are heterozygous have c0yp.3nq b/arsw1n4j.-n6 lm2 ksrw vhairs 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 pes(ucy:k78t9 vf vkk8x a plants was either round or wrinkled. The results of an experimental cross yielded 315 offspring with round8v9k cys7:(vkfx8uk t 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 mi+, cb7dltjl xm k5/6oany chromosomes are in a fertilised oocyte of a fruit bild 5,m6x k 7ojct/l+fly?

  When does the random orie3hcq4 m+ja 5:qxrv7 tbntation of homologous chromosome pairs occur?

The majority of the genes in the human gevr we6r t i8z)f/x;v3gnome have already been mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows onefr rv)6i ;xwg8zt ve3/ 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 linked genes?ge+sv39ie3 8bsr l2xk

  The diagram shows a karyogram of a brown male rat (Rattus norvegicus). Which arr;7 kp zd5nc,jh 6qcj;jow is pointing to a pair ;dpk6c,nj5z jhq;7 jcof autosomes?

  Mendel observed that there are tw/2e zfhrba4 9bka;yp9 o possible 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. What were the gene49yb2k ab/z;9 hfpraotypes of the parents?

  The graph shows the frequency of birth weight of chrzdl a55s-y0mildren born in London in 19910 y-slmdra5z5.

  Which of these traits is an example of continuous varig xjsk;mtwsisq9 hkl9 +b5u:1e8m).k ation?

  Which row correctly describes diploid and haploid cells in humar hv+)0 8j;rvezfjfsl3c 7lm)ns?

  The following table shows the diploid chromosome number of a range of spec5vixa5lu sl4t1qe 93 wies.

Which of these statements is correct?

  Sickle cell anaemia is causmx /dqda 1 h:83v.aar 5dofqg(ed 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 type A had a child with blood typ+ xx-cl nh3c*uqk (7bze O. What are the possible genotypes of thcx(ncxh*b l73uq+-zk e biological father?

  Which row shows the correct annotation sf5l(uu8g9s urchcg9a02e. -cp0kme of the alleles for blood groups?

  Which of these statements are true for al8 0k*n bqgjqw8:bee j1leles?
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 incidenfdj-izs* -5b:fe5hp q 34fxr dce of sickle cell anaemia and the spread of malaria across the c-:5z-hejffqdfi s5r 3 *4xpbd ontinent 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 o1 +y 25o5ptsj:o sregis determined by a number of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) colour (P) is dominant t og25j1s+yoetp5:os ro 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 ge,hyf vc2u/nx 78+otaa nes.

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

Sickle cell anaemia fye6m s-ddk .0is 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 f us9; /qmvq.veor brown, long hair and a fe9sqev;mv. u/ qmale cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), thvt1 xuuaox h9k s)(7 qss+xs8z9d+ma(e allele for diamond-shaped seeds (D) is dominant over oval-shaped seuq9t)(s oz1 9+daa s kxx+suh(s78mvxeds (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 hair (L) is dominant t si;)gdksn 7 h5ey); c0qxct8fo 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-haireds0snft)k 5d8 7c gei)cqxy;;h 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 in the ped) fhz8rk )5znzvx 8e1sigree chart below? 1e5shzrf8x )v k) zn8z

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

  Which of these statements about genetic disorders isxh*3 *bnzv 6hjmhif3 554sul g/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 showobjj) , hqsj)l bf*0 wk1nj12e 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 thf*bd)dxm) (fvw8n h4ye pedigree chart is X-linked recessive and not autosomal recessivdx wy8 *(fh))mfnv4bde?

  Different species of living organisms have d:6yx fii7/u fn/8qsm 3ikcme/ifferent numbers of genes characteristic to them. The table shows the estimated number of gen7 yx8:6e /ffm/i uq3kisi/ nmces 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 characteristicssg g x7o7tg;rg 8nf9(v 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 statem7tv(f ;gr7gx9n o8ggsents was correct?

  A biological male with hemophilia and a biological female without hemophilia hav ,-4ngk5fwcb ge a daughter without hemophilia. What are the possible genotypes of t,- bn45gwc fgkhe daughter?

  A dihybrid cross was carried out between two sunflowervnaqo65qs)- hhu 7r) p plants (Helianthus annuus) to see if the genes for seed number and seed shape are linked. The crihqnu)s6rq-p)7aovh5 tical 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 ty,-w q:ieu xoew8t0*1z kude k)pe B can have a child with blood typeozuqxk0eu,*:ewi1 k-)w t d8 e O.

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

3.Explain the role of inheritance in genetic diseases.