A man and a woman have a daughter and a son. Their daughter has normt8e5o qvqdo 41al vision, buo4o8dvetqq 51t their son is colourblind. 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 ma/a5 ov2c p se5bq+lde7le?

  There are two alleles for flower colour in snapdragons.(pdl uih. +g manul +.xq88x;2vk/hh s5w*yti 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 mol/gy xiud*hwvi28.qhl(kx +u 5t. spnh + ;ma8st likely explanation for this observation?

  Which keyword is matched to the correchjv fm ao/89b2kez x+-t definition?

  Which of these statements ii4+h6+ub egh fi2 396sivkf;fmyw8b cs a correct definition for a gene?

  The diagram shows a pair of hodjn6/+ii z+lgb nm66w ciri 7*mologous chromosomes.

How many loci are shown?

  Two individuals, hetero u8s9j*oz2- tj6 / 7hzk.sufgyol 4foozygous for a specific trait, were crossed in an experiment. Which row shows the expected phenotypicsy7kj fotf. u*o68 hs9z2zljogo-4 u / ratios of the offspring resulting from this cross?

  In some animals, the agouti allhvdbai v ).r5*x93gztma+r/qele causes individual hairs to have a banded pattern. The non-agouti allele 3 zrvdxv9) . ah+iam trgq*b5/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 ro )*+ iflqs:bwcund or wrinkleif)lcw: b *+sqd. 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 (Drosop( 6zicrv:b7 2xrpsbtkx)-5wyhila melanogaster) have 8 chromosomes. How many chromosomes are in a fertili)izcb:p x7r bsywrx(2v k -65tsed oocyte of a fruit fly?

  When does the random orientation of homologous chromosome pairs occud4v1zi,,t/q k4bn fayr?

The majority of the genes in th h yvrbqr5ccg91(w36ye human genome have already been mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one representation of a homologous pair of chromyr y q1gc (rvb3w65h9cosomes.

1.Define locus.

2.Identify the number of loci shown in the diagram.

3.Distinguish between gene, allele, and locus.

  Which is the correct deu h+ drk 1-:-zuylm+ e,ippo7yfinition of linked genes?

  The diagram shows a karyogrfhc0 */xqx18exhev,l .nz)lwl( 6t wl am of a brown male rat (Rattus norvegicus). Which arrow is pointing to a pair of a6v e0.llhxl ,x)h1zq (/*few wnl 8cxtutosomes?

  Mendel observed that tha pipf 9qibn ,pr*n+)h j)4kg,ere are two possible variations of flower colour in pea plants, purple and white. After a genetic cross, the ratio of plants with purple flowers to white frj)ikfqhn4p+ p,g i9pn * ba),lowers is 1:1. What were the genotypes of the parents?

  The graph shows the frequk j):e/hog (vhh(qnde(b0 b ln3 (l;upency of birth weight of children born in London in 1991)bel(( (:onn hj3gblu (qpd /khv;h0e.

  Which of these traits is an example of continuoww2go7i3q 4y6l yj8 clus variation?

  Which row correctly describes diploid and haploidvpcwac4 ljrzp 3j ;1x/ e42l/s cells in humans?

  The following table shows the diploid chromosome number of a range of specid-i 0a5rocrg 6es.

Which of these statements is correct?

  Sickle cell anaemia is caused by a re(p4.rqc / mp; 7v+won: kgnyapbp6j r.cessive 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 hx0lp7 2 1c9;ohvzf8qv0wy li9:ka y maad a child with blood type O. What are the possible genotypes of the biofzoy2y;m109w:0q palxkha c vli7v8 9 logical father?

  Which row shows the correct annotation of the alleles for blh+0r ldsi wa695i*tit ood groups?

  Which of these statements are truesv g vs3h;c*q7 for 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 anaemia and thed f1qedc1 hvf. zp+: hh4-bj;a spread of malaria across the continent of Afdhvz1 q1ahc;e4p- df+bh.f :jrica.


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 num*bd66 ;mtnu bg,ie1ia5jdmw 6ber of gea6meb5dt6u;n ji, bwdmg61 *i nes. 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 qsttsifv ,iq5:+y6o(q dd 7c :and unlinked genes.

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

Sickle cell anaemia iskd o0d)z.r5 9af.s oja2r1llx 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 for brgb6ic1*r;aqf own, long hair and a female cat that has blacbq*i cfr6g1a; k, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxat** )8sumdj1 yw fpl/acum officinale), the allele for diamond-shaped seeds (D) is dominant over oval-shaped seeds *yda f* ujt) 8/spw1ml(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 short27+pt xvnb8bt 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) wanp 8v+ txb72tbs 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 mj)n87w t wc+xcondition shown in the pedigree chart btc7w)jn wm+8 xelow?

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

  Which of these statements about gewqo 1f8nty( 4ltu:* oinetic 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 distrq+l(3 b t4bvsaibution.

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 ik6g m 6/ef*zwsn the pedigree chart is X-linked recessive and no6 6z/*s fmwkget autosomal recessive?

  Different species of living organisms have different n lf-bim981gyxi8f;nn umbers of genes characteristix-il;9fm8nf 18 bin gyc to them. 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 flo.p,t- c dphhh-wer colour. If the pea plants Mendel was studying can only be whitth ,-pd.h h-pce or purple and follow the rules of Mendelian genetics, which of these statements was correct?

  A biological male with hemophj+2bdcf5zt/ lilia and a biological female without hemophilia have a daughter without hemophilia. What are the possible genotypes of the daughtef 2 /zb+5cjdtlr?

  A dihybrid cross was carried out between two sunflower plannr daq q( ,u5io k6sny;:a3k6xts (Helianthus annuus) to see if the genes for seed number and seed shape are linked. The critic6d au635 :rniqkx oyn,;sa( qkal 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 co5btzj( ic)a/iwea2 ,an have a child with blood type O. a wa(ceb/ ,z2i5 io)tj

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

3.Explain the role of inheritance in genetic diseases.