A man and a woman ha 9+h)afar ejf7ve a daughter and a son. Their daughter has normal vision, but their son is colourblind. Which one of these genotypes could be correc)9hf7+aar fej t for the biological mother?

  Which diagram shows the sex chromosomes of a somatic cell in a human male?tjm 94-06dkra u7cdmg

  There are two alleles for flo7ag hf;9ui nm8jkg8z9 ie02miwer 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 ugmi8kgz2 n 90fei7h9j;m8ia. Which is the most likely explanation for this observation?

  Which keyword is matched to the correct defink,r 4hj m6r;rzition?

  Which of these statements is a correct definition for a ztzsgd4 8 8.ehsoq:z(c, qtb gr jt1(-/lf,togene?

  The diagram shows a pair of homologous czz:es** o,e;xfgu 5cw hromosomes.

How many loci are shown?

  Two individuals, heteroz9ocugkhg/zdis0 t hd 2g8*).e ygous for a specific trait, were crossed in an experiment. Which row shows the expected phenotypic ratios of the offspring resulting fe tu 9h).gggz*c2k0ddis ho 8/rom this cross?

  In some animals, the agouti allele causes individualtgz73c t- wgx+ hairs to have a banded pattern. The non-agouti allele causes hairs to be a single colour. Individuals who are heterozygous have hairs with a banded paxcgtt7-3 zg+w ttern.

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 individuadbq*0 16cdda ul pea plants was either round or wrinkled. The results of an experimental cross yielded 315 offspring with round seeds and 105 offspring with wrinklec 1*dq0d6 uabdd seeds.

Which row in the table below states the most likely genotypes of the parents?

  Neurons of the fruit fly (Drosophila 91mjqx+xb63 64fxmpay 9eda nmelanogaster) have 8 chromosomes. How many chromosomes areqa9m36 xbja4py6exxd fn 9m+1 in a fertilised oocyte of a fruit fly?

  When does the random ori ,unojtk /e:l7fqiyml. 06q*gentation of homologous chromosome pairs occur?

The majority of the genetro 9 c6u*2gm2 sbk0exs in the human genome have already been mapped, meaning the exac t602esc 2k*mgbu rx9ot locations of the genes on chromosomes 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 linke 4wv b quoy:-49vaex9qd genes?

  The diagram shows a karyogram of a brocfw4) rbaxend l4vata*(+ fw r5359bv wn male rat (Rattus norvegicus). Which arrow is pointing to a pai9ae)rrt5 f (w 34bvwxva+ b4flacd 5n*r of autosomes?

  Mendel observed that there are two possible variatio2k7/ go 8mf8z2 lcbqdons of flower colour in pea plants, purple a 2/fqlo7zob2 8ckgm d8nd 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 London ssho 3l:r;*8ezm( p xpin 1991.3r;p8eps( h: zml*sxo

  Which of these traits is an exam5x emkx*da ex5n20,k hqr o4l-ple of continuous variation?

  Which row correctly describes diploid and haplom1acz zqs4t.6z ;eov.id cells in humans?

  The following table shows the dipl2,kin.fo ytvx e+5: huoid chromosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is causeiie)0kvc fw,(/o9zoq)3 jmm ld 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 xva *i+t n 9eb3ze.vzz(1ff7xblood type A had a child with blood type O. What are the possible genotypes of the biological fatherfx za9ee+7i t.zz1(*bv3vfxn ?

  Which row shows the correct annotation of the alleles for blood groups5e6q zcrrijj0cuj6sp 5:3g+x ?

  Which of these statements are true for allx ap33vod 6rwo,h l3r:eles?
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 sickles7b. t :a5xyq jr4)wtw cell anaemia and the spread of malaria across the contit bw 47t). 5jqxwa:srynent 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 by a nz1 uhi;udch7yq:q6lloaf;yj3 .9( k wumber of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) colour (P) is uuo.;z(hq kyfl7hi: l1ad;6 9qyc3w jdominant 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 und8 pj0z yh2 /1lzphn4qlinked genes.

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

Sickle cell anaemia is caus (c n,igjk nf2zmeo d+j5t,0v.ed 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 for brownn 3g1m lrfe-.+uv. gbs, long hair and a female cat that has black, short hair. v.g.nemb u+s lgf-3r1


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamond-shaped seeds (p( .kvu, )v/uliqz4sf D) is dominant over oval-shaped seeds (d) and the allele for long seeds (Ls (vuzuipk.v) lq ,f/4) 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 sho vht..v*y:s pxj :to8fkig,/urt 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-h j.p*fxtyi vks/o.: uvh,g8t:aired 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 pe8prxrd06 v0bkdigree chart be6 dkp08rvxrb 0low?

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

  Which of these statements about genetic disorders is/are cpb2/ha(hq;g k tbhre6p,. f0 morrect?

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 ais/:mf) dv n;1s i(jfi 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 pedigree charxk+c0 :jbcqyf 46+9odr bsj((m fcr (tt is X-linked recessive and not autosomal recesfc 4bkyrt( (q 69dsx(+cfbmoj0+rj:csive?

  Different species of livi lx, e93a)d6 gn5ex yxxb:u c;;tebuy,ng organisms have different numbers of genes characteristic to them. The table s5uyeyx9 e)x bn,:; ,claebt6xgx;d 3 uhows 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 0v r32uf ko tpumbi2z 1qn0 62a8nux7dplants, including flower colour. If the pea plants Mendel was studying can only be white or purple and follow the rules of Mendelian genetics, which 2uu8ft71 6no pna u03di0x2bmkq r2 zvof these statements was correct?

  A biological male with hemophilia and a biological femaam6,e mmr8r,5ndv5 n nle without hemophilia have a,8mnmnmna5v rr, d5e6 daughter without hemophilia. What are the possible genotypes of the daughter?

  A dihybrid cross was carried out between two sunflower plants (Hel:jges6w 7y;h.dj q(sxianthus annuus) to see if the genes for seed number and seed shape are lin:ejj s (y7;hwdxq.gs6ked. 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 zi)9tfmyg:x4 yn :j (otype A and blood type B can have a child with blood type Of gyzmn yi):9t o:(j4x.

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

3.Explain the role of inheritance in genetic diseases.