A man and a woman have a d;(6m,6mqi ur xefvzf8 ub-aw uk3)6 wkaughter and a son. Their daughter has normal vision, but their son is colourblind. Which one of these genotypes could be correct for the m 6u ;v uuw6-8zqb 6f ,raf3w(iemk)xkbiological mother?

  Which diagram shows tyzoq(ul/s+1a l6) j,fzg vpg9he sex chromosomes of a somatic cell in a human male?

  There are two alleles for flkb65: -p.k m f.:apexfgi4+c q3 greorower colour 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 t:c fg : 43+a-k.bpp fg .r65qxmkieorehe most likely explanation for this observation?

  Which keyword is matchedm7 g az,v-jzq, to the correct definition?

  Which of these statem 2r37kq wn*6b1lh.p /sg1bpu3ekfuusents is a correct definition for a gene?

  The diagram shows a pair of homologous chromosomes.xt6z:jli ( cp-qr26 z zdz/ci.

How many loci are shown?

  Two individuals, heterozygous for a specific trait 7 yb+ijbh5-;n m(gtq kdm+f*+jd+cct, were crossed in an experiment. W(qtmg; yhmkjj - +nd d5b+cc*it7 fb++hich row shows the expected phenotypic ratios of the offspring resulting from this cross?

  In some animals, the agouti allele causes indivicv)1 prn;ew 3 2c79qo 1ranovudual hairs to have a banded pattern. The na1rv7ure);92 qvop13nocwc non-agouti allele causes hairs 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 was either roux yp 1rimw;7m-nd or wrinkled. The results of an experimental cross yielded 315 o mmx-ri;ywp1 7ffspring 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 (Dross+kpc hv64 u 9.7snaoiophila melanogaster) have 8 chromosomes. How many chromosomes are in a fertilised oocyte +s c.skh9npiu4vo 76aof a fruit fly?

  When does the random g:kf4y ge4 y,i;xjh*e orientation of homologous chromosome pairs occur?

The majority of the genes in the human genome have alreadi24u:sjjghch aepz tn*(r)kj+r(2t 3 y been mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one representation of a homologous pair of chromo3h t tz:j2i(h4gnuk(2s c r aejpr)+*jsomes.

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 l zxbgb nkl30+.r q3de:v3 pw0iinked genes?

  The diagram shows a kw5)1 as8f n/nw yvhde,) fz2zlaryogram of a brown male rat (Rattus norvegicus). Which arrow is pointing to a pair of autos,f/s))lf8 we y2dnaz nwh5v1 zomes?

  Mendel observed that there are two possible variations of flower colour in pea pwzmb- 1w -;xpylants, purple 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 pyw-p bw;z1 xm-arents?

  The graph shows the frequen--d)v* .9bdl/qrwmz2xdy 5 gmu pvrn )cy of birth weight of children born in London in 1991.)qbr m5gzl dmdpu.-y/9 v-nxrw 2v)d*

  Which of these trait -x5aa,* 6xlgcau-txxs is an example of continuous variation?

  Which row correctly describes diploid and haploid cells o; tdk-mc674hhy /;naul-uco in humans?

  The following table shows the diploid chrom9usu vv* m25hb t2y-jbosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused b;s tg5hp+ (hne 54tjsm+:w xxyy 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 withtyplh 2hg-721* z jg wo 8rne+f7rmasfp x+:0u blood type A had a child with blood type O. What are the possible genotypes of the biological father l*o 721pxgpf 72r+ :+ 0utrag8nejh h-ymwfzs?

  Which row shows the correct annotation of the alleles 15 vrxpghlm7 h(4uxh) for blood groups?

  Which of these statements are true for allele9u8qk zv8xgtvbz7 ivg00 l y(7s?
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 lm5hc(v+dbh+ +mfap od,dw 0adp3* l,cell anaemia and the spread of malaria across the cl3(,fv,dp+ *db+dh50mp dwhl+ amao 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 determined b chxa v ( b7fpn)7s(m:tm:cz-.gos wx2y a number of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (twm .o(7(zcacwsgx7f: :)xm2vns t- hpbo 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 genes. bkiu8y80hgl+o2 l)o/8juaip

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

Sickle cell anaemia is caused by the allee3+o8:-qrk oq 8uwiknl.w0 zmle 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 crossn pp i8(:;v ,sl1*hjq )yvtmx5f7oggjc:g cj. between a male cat that is homozygous for brown, long hair 5*gh;.ccsp(:yvn,lv q opg jx m1:f)jt8i 7 gjand a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), th0r(j dtcp* tg.e allele for diamond-shaped seeds (D) is dominant over( tjp.r0g*tc d 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 dominant to short hair (ai3bv5k1bb1o6 w,hwv1b 5t wk l), and curly hair (C) is dominant to straight hair (c). A test cross was carried out between male heterozygous l3hvk a1wo5ki1 b 6b ww,5bv1btong, 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 conditiovbfmmdo u8/9o 0s1 9dwn shown in the pedigree chart bd fd0wusoom8 mv/91b9 elow?

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

  Which of these state:+ ,g a+eecj7 ,qegmyrments about 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 2c+5 v.w2+dtjsdx3elms/ zxj -zja +udistribution.

2.Outline the differences and similarities between homologous chromosomes.

3.Explain why expected and observed Mendelian ratios may differ.

  What suggests that the inheritance 17za.ci 2 zytr5ulc )mof the disorder shown in the pedigree chart is X-linked recessive anmla ur7 1czt.2c5)izyd not autosomal recessive?

  Different species of living organisms have different numbers of genr*s z 54lkq6 f a4-1dfoqe4eices characteristic to them. The table shows the estimated number of genes for4f o f1kdqa c-zie*leq 45rs46 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 flowern7+q a zk10 mp,o68ad fgxq5lw colour. If the pea plants Mendel was studying can only be white or purple and follow the rules of Mendelian genetics, whichkxd7zo a6f0ag18 w,+p 5n qqlm of these statements was correct?

  A biological male with hemophilia and a biological female without hemopg) lxmxs mnjgm.415 om7 76ww ym+ qig.pr5pj;hilia have a daughter without hemophilia. Wh6wg 5gy 7lnm wmj jm5xi +;sg.m)p1p4.omrq 7xat are the possible genotypes of the daughter?

  A dihybrid cross was carried onabba+pxqtg ft, kwo+:*0m3 9 ut between 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 the 0.05 significance level was 7.82. The calculated valutpb+g*:on m,kfx+9w baq0a t3e 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 + 4/ g(/ uijl4d(saewjajef l3have a child with bloof w((iedll ajg434u/ /sj ej+ad type O.

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

3.Explain the role of inheritance in genetic diseases.