A man and a woman have a daughter and a son. Their daughter has no) v ubm472x87ugbyvi efl9s w9rmal vision, but their son is colourblind. Whichfbuls9y9vu7xi4b wv e )m28g 7 one of these genotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic cell in a v8q +s0yw mcbs8b 8d3t3aj(xa+ aw:fk human male?

  There are two alleles for flower c mma4s7)/lwbb 2s1k geolour in snapdragons. 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 ths7bab)esk2m4/ mgwl1 is observation?

  Which keyword is matched to ;br tv. i+fe5hthe correct definition?

  Which of these statements is a correct definiyb7a*q+t; 5og( veo7q .x vpwztion for a gene?

  The diagram shows a pai0vwlvi.r qc- *r of homologous chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait,glyw7xw7h,jiyc z) / - were crossed in an experiment. Which row shows the expected phenotypic ratios of the offspring resulting from ti7-,w /lg)7h wxc yzjyhis cross?

  In some animals, the agouti alle1y:r qd;9 vkgl mfq.m5qz6:ma(j9 karle causes individual hairs to have a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who are heterozygous havvy(9:r1qk j ; :grmq95mdaz qfa.6kml e 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 eitherqknb*h1y 43 ed9rt,zm round or wrinkr,e 1 b4qy kmnth3dz9*led. The results of 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 o vz-(k i8i thm;xz(,nmelanogaster) have 8 chromosomes. How many chromosomes are in a fertilised ooxi nti( mh,z;v -8(zkocyte of a fruit fly?

  When does the random orientation o. n6il2z k5qk w,fu;1ip;n96kjon asy f homologous chromosome pairs occur?

The majority of the genes in the human genome have already been mv+w5 r-e )i dgwh5tf; 1xwu1ayapped, meaning the exact locations of the genes on chro55)t1gh wfxa ;wy eruw1+i-v dmosomes are known. The diagram 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 of linked genes?xxkki*h: ;(lx

  The diagram shows a karyogram of -.ih7k6g tqd , vcdt:na brown male rat (Rattus norvegicus). Which arrow is pointingdtq.t,nch:7 ivg k -d6 to a pair of autosomes?

  Mendel observed that there are two possible variatib5) dcm : vwk.:a1ldibons of flower colour in pea plants, purpla blvmd:1kd)cw:5i b.e and white. After a genetic cross, the ratio of 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 Lonqwx,rbbq l b0np(-0gt1;*tex don in 1991.; l(qw1rb*b q bt,teg nxpx-00

  Which of these traits is an ebwq uhcu*m 73)xample of continuous variation?

  Which row correctly descirs1(ap5wx 9l s( 8v4ankwzt7ff0 6 yvribes diploid and haploid cells in humans?

  The following table shows the diploid chromosome nux hbo*5dlccmc,:x7 olj1 h((pmber of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused byprx6:o x1p5u 7 iz0lzq 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 are t e6fgtosg9 wb hmsyycdj i)(9x 34,zd.,k94 xkhe poso4f) gb(39t y s 4jeskdmi99,k, w zcgx6hd.xysible genotypes of the biological father?

  Which row shows the correct annotation of the alleles fofmd4d,2i u; gweuc3+c r blood groups?

  Which of these statements are true for c l+9tqztuz.* 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 anaemzn- 7/+w9w wy dsq+hvqia and the spread of malaria across the continent ozw hwsvq9+-qw d+yn/7f 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 determinlhx) g bv7.fj2ed by a number of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) colour (P) is dominant to one tone ( hl2)g. b7vjxfp).


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 andzdn* hf*wl-z6 unlinked genes.

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

Sickle cell anaemia is cause )zheux:*(-be* huzky0vcp1) .aah ced 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 f49h 0jkx cq9bcross between a male cat that is homozygous for brown, long hair and a female cat that q4hkb0j 9 9fcxhas black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamond-shaped seeds (D) is, i.4no zp8kxs dominant over oval-shaped seeds (d) and the allele for long.ps4ikzxn8o , 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), e6 tnzb*kd::slong hair (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 out on b6se d n::zt*kthe 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 cend7 lkdim- w22w g 60/sm)oryondition shown in the pedigree chart below? id) w2-2md7y0 rsok/mg l6wen

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

  Which of these statements amued.xb+7g h53f ye 7obout 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 can show a normal distribut)x:rxg .y tq,wion.

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 pedwne 00i5ymraf ;+,qad igree chart is X-linked recessive 0 eard,yf i0wq;n+5ma and not autosomal recessive?

  Different species of living organisms have different numb:kdya8z u 0s ke*lxj.6ers of genes characteristic to thjsel *:xza d8.6uy0kkem. 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-sufkj ya 2qj,oq03/ a pea plants, including flower colour. If th k,3j0qyfajsoa/-uq2 e pea plants Mendel was studying can only be white or purple and follow the rules of Mendelian genetics, which of these statements was correct?

  A biological male with hemophilia and a biological female without hemophilia h sbzpcdt(d.+q lu9, c/ave a daughter without hemophilc/ 9bpd.d+lcu q,s(ztia. What are the possible genotypes of the daughter?

  A dihybrid cross was carried out between two sunflower plany qvwat4arp6 ,h66 wjvp wm9( k8wzl3*ts (Helianthus annuus) to pl4*69 w,pwz(3tm6hyvja8kq arv w w6see 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 indicate?

1.Explain how parents with blood type A and blood type B can have a chifw +ig-09orxsld with blood type +o0r-gwx9 ifsO.

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

3.Explain the role of inheritance in genetic diseases.