A man and a woman have a daughter i 6kq: culz04kz12tyxand a son. Their daughter has normal vision, but their son is colourblik6q :i1y c2ux4z0ltzknd. Which one of these genotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic cell in a human malf qea8 0iks)e1 d4ku gkyin76b7wxi*4e?

  There are two alleles for flower colour in sn9z n-d:a6xj q3 5lq(mfllqhp 3y o:vp7apdragons. However, the result of a cross between two heterozygous plants yielded offspring with three different observed phenotyp5p3nqao ( :z-p 6jylldhf3ql9m: xvq7es, red, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to the corn/e6o;w +jqb dlr.ju,rect definition?

  Which of these statements is a correct devw3h ve y/fnj /3:ftvg y5y0t3finition for a gene?

  The diagram shows a pair of homologou/fkre3v :q 8krqyie/x z 4k0)bs chromosomes.

How many loci are shown?

  Two individuals, heteryrh f: yq-p fm0*/bt-vozygous for a specific trait, were crossed in an experiment. Which row shows the expected phvmhf-*-tqy:rpy b0/f enotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti allele causes individuva cd: hyw8o/)al hairs to have a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who are heter8whdv / c):oayozygous 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 either rzu 9 2ru z5b)l7-7nlz/vmloybound or wrinkled. The results of an experimentaloulbr)77z zy- /9z l2mbu5lvn cross 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 chromoso5(6 0az b vtdwuxc4vu y(ewp,)mes. How many chromosomes are in a fertilised oocyte of a fruit flu0xv a dp b 6e((4,tcwy)uzvw5y?

  When does the random orientation of homologous chromosome pal;tqkg8 xwz zwl2);8eirs occur?

The majority of the genes ba9:big + e8splqwjv 4ia.nj/,gc5i7in the human genome have already been mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one representag8/v, w+ej5ja i 79b.pn4bigcsl:iaqtion 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 lin(:q vpw1 u:b:zzibe.p ked genes?

  The diagram shows a karl.q ys+t f4xq;5p yfd2yogram of a brown male rat (Rattus norvegicus). Which arrow is pointing tfpy4q 2 d.xyf;ls5q+ to a pair of autosomes?

  Mendel observed that there are twotvnalc0v6 5d 9 possible variations of flower colour in pea plants, purple and white. After a genetic cross, the ratio of plan l6vvn90ct5ad ts with purple flowers to white flowers is 1:1. What were the genotypes of the parents?

  The graph shows the frequency of birth weight of children born in Lonziy/dhf- yehw) zv 812don in 1991.f) evy81dhz yw/z2i -h

  Which of these traits is an example of continuous variation?w9izw 0*r l7p2)mg d0p3r 7 zhozmkjq9

  Which row correctly d-n5k4*i-nni-k q gg ygescribes diploid and haploid cells in humans?

  The following table shows the diploid chromosome number of a range of spe b9o ,8q78k ewb6kdi2eaouc7bcies.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive w1 mvmbrm6r9 ax0p81dallele (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. W ih90+kk+qwk.sgl+g c hat are the possible genotypes of the biological fatkhk0 .gw+ls+q+ ick9g her?

  Which row shows the correct annotation of the alleles forsw.v *z(.flhfmdj d11 blood groups?

  Which of these statements are true fo3-:jf syfcil 11d;qeg/f nr+ nr 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 o)mls6x kf+sk) f sickle cell anaemia and the spread of malaria across the continent of Africa.6 f))kl xsm+sk


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 przewalskiifne0 /2 zrti:yw h)f-l), fur colour is determined by a number of genes.):w0e-hin2z l/t yff r Brown 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 linked and unlinked./2g2lotegtlam+ 5ew genes.

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

Sickle cell anaemia is /wt , zxi qeiuhya.jl3j*-(f,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 for2+ef00n-)my/xc cfm+qpfl tw brown, long hair and a female cat that has black,qp0w2xln)yf+e +/m -mct0c f f short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamond-shaped seeds (D)s4m n77aemx hu* yo :2f;9toxq is dominant o2xoshtfaq7:*x 4u7n; mmy 9eover 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 hair (L) is dome/xe pt (kyqfz ies(2iuzd*(sa -mc1:eu,s:/inant to short hair (l), and curly hair (C) i ,e(z:y/fut (*isqzmp2e aue:d(exsk/ c-1 sis 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 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 y7z) -r)cm tv4ipi-beg i /my;the pedigree chart belvt--y/zii i mmgbr7;4 cyp))eow?

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

  Which of these statements about genetic disorders is/are cc5yhn pi8qj0 draj.; -,5l ysuorrect?

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 traitse7ru ( :,a1qxswtezq0 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 inheritance of the disorder shown in the pedig /ziq)vz vjo6py x2+ x1k6,ydgx,r/gu ree chart is X-linked recessivekpz) y d66/gg,iv +q,zjyr2x/xu xov1 and not autosomal recessive?

  Different species of living organisms have differec*:qfpc g r8+(ea nee-ko++ gfnt numbers of genes characteristic to them. The table shows the estimated number of genesge en +(:ra*f8coc+pekq-+ fg 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 chaul g+m6s q:g1 jea9vb,racteristics of pea plants, including flower colour. If the pea plants Mendel was studying can only be white or purple and follow the rules of9 +6lauqj :ev, 1bmggs Mendelian genetics, which of these statements was correct?

  A biological male with hemoph(*)i xpq0 xjch yw6da*ilia and a biological female without hemophilia have a daughter without hemophilia. What are the possible ge yjx*0* )6wd(cqa iphxnotypes of the daughter?

  A dihybrid cross was carried out betwenxq; 8am pgd o/ qt,h-;+abuj(e3ux8x5 rm7bc en two sunflower plants (Helianthus annuus) to see if the genes for seed number and seed shape are linked. The critical value for the chi-squared test at /p3,;n-a b(mjxc+u 7xa8qx5h8doq egrub m;tthe 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 andvh9 +a6n dm2hvl+w2dq blood type B can have a child with b nwv+ vd6q92 +dhlam2hlood type O.

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

3.Explain the role of inheritance in genetic diseases.