A man and a woman ha f0fzi*brpb)rj+wyfkw y2a5cz.u(a7 j e ;o/1ve a daughter and a son. Their daughter has normal vision, but their son is colourblind. Which one of these genotypes co)f+w j7y/ioy ffa 2acw;rz k* .bezu(pj5rb01uld be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic cell iozf5) ge*jwgz ,1qsn: n a human male?

  There are two alleles for flower colour in snapdragons. Howevu*9brc z9r:lxer, 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 explanati:*9uxrl9c rbzon for this observation?

  Which keyword is matched to the correct defiv.593/mxglu 3edo oh 1 xu1+umsxq3usnition?

  Which of these statements is a correct definitik :j +5: vkg5c1nouojyon for a gene?

  The diagram shows a pair of 17hi y ko,vus08xca,hhomologous chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a sp c1f;m :+;6,ux3u faaho lohaopsf69pecific trait, were crossed in an experiment. Which row shows the expected phenotypic ratios of the offm:9 ofuplf31 ;hohf sc+ ,6 xa6puoa;aspring resulting from this cross?

  In some animals, the agouti allele i)ow/l1k h0amt4a,k7-ab bjga r vh0:causes individual hairs to have a banded pattern. The non-agouti allele causes hairs to be a single c0at / ib7kjbmga: r, 1l- havhao40)wkolour. 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 rodn runzb j:obf22/ ;m/und or wrinkled. The results of an experib;/ dmfnnj:/ob2r2u z mental 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 (Drosophi2l9wd,il ;i tula melanogaster) have 8 chromosomes. How many chromosomes are in a fertilised oocyte of a fruit flyltwd, ;9 u2ili?

  When does the random orientation of hogs m+k/4jac 2lv g33iwmologous chromosome pairs occur?

The majority of the genes in the human genome( m( n1mn,dt+u0ecvf x have already been mapped, meaning the exact locations of the genes on chromosomes are known. The diagram below shows one representation of a homologou (c xt0 nu(+mdm,ve1fns 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 de4syog)na dt; 5finition of linked genes?

  The diagram shows a karyogram of a brown male rat (Ratgcu10o6 0or.gkfiqsk hv)o.9c f )f0ytus norvegicus). Which arrow is pointing vcfi0h gcooyf).)009 rs gukf1o6.kq to a pair of autosomes?

  Mendel observed that there are tlz0b hc3/ z y zg+: iarpj,,ald/*+mypwo possible variations of flower colour in pea plants, purple and white. After a genetic cross, the ratio ofa,p/zymr3+, l l j0 ib*apy+z gzdc:h/ 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 Lr)c7m:d g;g1fs)ue )a 8nsk-coa cnr 9ondon in 1991. r-cd sg soc;f)mc a)n)917ueg :8rank

  Which of these traits is an example of continuous5y0fo3lw 2 muv9 uswk3n1 5odo variation?

  Which row correctly describes diploid and haploid cells in 5cs*foe-*qn*p nhu0pve m wx7h26rv 7 humans?

  The following table shows the diploid aqkmxwz57 m6 4dxu8iuve04 2nchromosome number of a range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recesad +vh ,5zwp5fv sy,r/sive 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 )bcq b t+nad8bs2fnz) j2v5t2O. What are the possible g sjbv5n8) 2zt2)aqc btdb+ 2fnenotypes of the biological father?

  Which row shows the correct annotation of the alr79b9txj0tvjtp j i8)leles for blood groups?

  Which of these statements areafha7gc;)- oofdt : 3jh-miuuxy+7 6 w true 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 celyovmlx*i: vh m.xs4qp.x3k +/l anaemia and the spread of malaria acr/yx:. lq v +kxm.3h4mx*spvoi oss the 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 by j5j0v aa n4bj 92isbfi,c 4c(5 k3f 6of1epiwda number of genes. Brown colo2acp5 ,3(v9b16i5e4bj0s fd jjw4nikffai ocur (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 tw:f- 1mnsx 4qunlinked genes.

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

Sickle cell anaemia is ca4i yid(i; oy qw(( r2rx(l-uraused 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 catjw36 acg*b+x sevccgw8v(747ytxep. that is homozygous for brown, long hair an 8ex6gyx.3t7vv7*w(c wsjpeg+4bc acd a female cat that has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the alx-)hqqobi301 kf wv.elele for diamond-shaped seeds (D) is dominant over oval-shaped seeds (d) and the allele for long seeds (L) is dominant over short seeds (l)k3.1o 0)w bhi xfveq-q.

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 (g)+q n s9gs(fal), and curly hair (C) is dominant to straight hair (c). A test cross wa)q gg+(fns 9sas 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 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 ped7,xa5x i5gj5tztli7 ligree charttl5lx5izt x,7ji 5 a7g below?

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

  Which of these stateme8k3: c9bsfex ants 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 v*it mpsl.hrek) p20+ 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 disorder shown /jhqmo5 .mjz29c4op nin the pedigree chart isozopm25 m.c9j4nh qj/ X-linked recessive and not autosomal recessive?

  Different species of living organisms have difddl7 yq3, tk96ulciq3ferent numbers of genes characteristic to them. The table shows the estimated number of l3clu,7k6dq 39yid qt 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 pea6jr5s u1fsdo+ plants, including flower colour. If the pea plants Mendel was studying can only be white or purple and follow the rules of Mendelian genetics, whic uodsf65 r1+jsh of these statements was correct?

  A biological male with hemophilia and a biological femaleyz4 h) c ne5qt,,sn+.ty fc k(fs1rz2o without hemophilia have a daughter without hemophilia. What are the poss,+ (zzr1c) snq,ynt.f2fs4keh oy tc5ible genotypes of the daughter?

  A dihybrid cross was carried out between two sunflower plants (Helian ) ;e*om.jwbjkthus 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 value for the chi-squared test was 10.05; what does b jowj);km.e *this indicate?

1.Explain how parents with blood type A and blood type B can have a child wina6hml my7ss l; 4y5)mth blood m4s mhs6yl a;n7l5)mytype O.

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

3.Explain the role of inheritance in genetic diseases.