A man and a woman have a hf:rq / x4- 3:dtgdsl32umegvdaughter and a son. Their daughter has normal vision, bu-l/ ghf:ddmur43g2 q sxt3ve:t their son is colourblind. Which one of these genotypes could be correct for the biological mother?

  Which diagram shows the se uk5 -sir-+mdcg48vjgx chromosomes of a somatic cell in a human male?

  There are two alleles for flower colour in snapdragon.l f yiwax-z18s. However, the result of a cross between two heterozygous plants yielded offspring with three different observed phenotypes, red, white and pink flowers. Which is the most likely explanation for this obserz x1f iaw.8l-yvation?

  Which keyword is matched to the correct deqyd j5)yczyjr 4 2-wk1finition?

  Which of these statements is a correct definition *p3d1 nlo86 mojfmdx0 for a gene?

  The diagram shows a pair of homologous chq0(dycbe/ 93r wv*pvu)g3q oz4t qz h8romosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, j3fkleg nuiy* d8 ds;- x+kkl/h 7p5i6were crossed in an experiment. Which row shows the expected phenotypic ratios of the offspring resulting from d k- fi58 xyi7nk+sg ;/ upl3*j6kldhethis cross?

  In some animals, the agouti allele causes individual ha(xfj)pos/t/ f15b k;pnv+j bnirs to have a banded pattern. The non-agouti allele causes hairs tos) bpjf v// k;fn(jptb5xn +1o 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 individual4m jrmy4c n8s3)y0exbb hnteq85 p)- q pea plants was either round or wrinkled. The results obhbr 483mns5qcn y)t0jmy )p4e e8-xqf an experimental 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 ma+au;-* akz (pndxu6 felanogaster) have 8 chromosomes. How many chrou; u(6 *fp x-azdkana+mosomes are in a fertilised oocyte of a fruit fly?

  When does the random orientation of homologous chro w ww,1qubpr8+mosome pairs occur?

The majority of the genes in the human genome have already bi 4xq 7c:oe-; ww2n4p ytnyzl4een mapped, meaning the exact locations of the genes on chromosomes are known. The w w:zqlni444 7y-;teyn2xp codiagram 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 v+1 d;acdtqpn **d,mm of linked genes?

  The diagram shows a karyogram of a brown male rat (Rattus norvegicus)r6d nsnjr 4-l2. Which arrow is pointing to a painlrdrsjn- 246 r of autosomes?

  Mendel observed that there are two posse0(5di + rorxrible variations of flower colour in pea plants, purple and white. After a genetic cross, the ratio oex(r 5+orri 0df plants 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 London in 1;j2.jftll jpj a,/ qhww b2q*kqz,5z j;1. ntp991.*n j2pb, h,;z.k;pjql.tjq2t 5j fqw1aw/jlz

  Which of these traits is an example of 6dwae3q;m tq3continuous variation?

  Which row correctly describes diploid and haploid cells in humap4bts+zx;( c uns?

  The following table shows the diploid chromosome number of a rw ev4 5zkw.r e:xc:*vyynl5d 2ange of species.

Which of these statements is correct?

  Sickle cell anaemia is causem. oj5)p7 rbtnd 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 type O. What ar5 h 5idjq+v+ebqlh4u:e the possible genotypes of tuhd45l++hv5ej:i qbq he biological father?

  Which row shows the correct annotation of the alleles 9 9t8zoj3z rhbce u528zf5*i9wybl jqfor blood groups?

  Which of these statements are true for r56,r6uenpym4 : dtjaalleles?
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 anaemia 6jc brvs+i;zw6/w; d4:wthcaand the spread of malaria across th6sb i+azd r:h t6jc; c/4wvww;e 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 vw*m a.z99ckg /pn9gm3cs8 uxdetermined by a number of genes. Brown cpgxcm.w/ vc 399ku 9an8*mgs zolour (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 unlinke*q+99*zbfsxgj2 u e xj7gudi0d genes.

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

Sickle cell anaemia is caused by the allelhvx w 9ov.04see 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 i0e27(;kpewnlgw.z p g s homozygous for brown, long hair and a female cat that has black, shortpg0e.glpw;z nkw2(7e hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinalex+ 7-stn/ p.aq*v0dq8 iyl ayr), the allele for diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) is dominant tqq 7av*-ny/8lis p+0ax.dyr 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 to short hair (l;(; og(kr jmkc), 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 guinecgmk(; (kj or;a 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 con54ip2t-8dodcsy l z6j dition shown in the pedigree chart below? 5iod jz-8d6l2 4sycpt

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

  Which of these statements about genetic disorders is/are correct.u wzgwhb:z2yo-2/ ba ?

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 d6c01: ltl,ov obd+z,x:ip dsf*e pw ;traits 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 diso// xt9cn6rk8bhn s(blrder shown in the pedigree chart is X-linked recessive and not autosomalh9blxs /r 6(n8nbk/tc recessive?

  Different species of living organismsnt*;6*vx7rn*o :svclx g gl0c have different numbers of genes characteristic to thv*nogvn7src 0;* :xtxlc *lg6 em. 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 characteristics of pea plants, including flower coli ;xyf1haj16q our. If the pea plants Mendel was studying can only be white or purple and ;a6 1xqi1f jyhfollow the rules of Mendelian genetics, which of these statements was correct?

  A biological male with hemophilia and a biologin82id n lbw76vcal female without hemophilia have a daughter without hemophilia. What2iv86 lw7nbnd are the possible genotypes of the daughter?

  A dihybrid cross was carried out between two sunflower plants (Helianthus oj nun2mdsjzp+743 u 8annuus) to see if the genes for seed number and seed shape are linked. The critical value for the chnjuuj4nm27 ps z+ 8o3di-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 type B can have a chi w/61 pqwyel* uh5y4suld with blood sy/w541e uq hl6puw*y type O.

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

3.Explain the role of inheritance in genetic diseases.