A man and a woman have a daughter and a son. Their daughter has normaqv: os-st*:f nf 8aj0nl vision, but their son is colourblind. Which one of f: *ojn8n-v0 :ssqa tfthese genotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic cell in a human male?co* oh:. khvo+p34f an

  There are two alleles for flower colour in snapdragons. However, tcgd:9pi3.s)/mw4.i l+ygrjw9pg x crhe result of a cross b. gi swi .jyrwd)crmpcp99g+l4/x: g 3etween two heterozygous plants yielded offspring with three different observed phenotypes, red, white and pink flowers. Which is the most likely explanation for this observation?

  Which keyword is matched to thk3j lhv88h st,e correct definition?

  Which of these statements is a correct definition forrkg pp7 8 mojz+kb0jii0l 0l8+ a gene?

  The diagram shows a pair of homologous chromosomesalx-,a.dh .e*aus /ea.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were crossed in an experimen/x acu/00mw(xapq bp* t. Which row shows the expected phenotypic ratios of the offspring resulting f pucw/* bp(maqa0xx0/rom this cross?

  In some animals, the agouti allele causes indiviyhq 4bx6(s;ahp*ff6 v ptnl1 9dual hairs to have a banded pattern. The non-agouti allele causes hairs to be9 6hhlsfvt( 4aqy;fxp 6p* nb1 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 in uu4zz i2dgm1--i5uo3o0o zzw veq f34dividual pea plants was either round or wrinkled. The results of an experimentm o0e wzfu1gui3z- ozq245v izdo34u-al 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 f: dd d v2n7asj253igbyly (Drosophila melanogaster) have 8 chromosomes. How many chromosomes are in a fertilised oocyte ds3d7:dg5n 2bj i2ayvof a fruit fly?

  When does the random orientation of homologous chromosome pairs vn*1 9hdltx2f gqzy1; f+rh)ooccur?

The majority of the genes in the human genome have alread843vzpw;k y.1jw nch qy been mapped, meaning the exact locations of the genes on chromosomes are k 4p w1y.qhjzcn v8w;k3nown. 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 )cjp)1txg h7plinked genes?

  The diagram shows a karyogram of a brown male rat (Rattus norvegicus). Whinr z br4fil:92ch arrow fl2: 4b zin9rris pointing to a pair of autosomes?

  Mendel observed that there are two poss +hp-u+oj+3j/buxdkzfr6 m: h ible variations of flower colour in pea plants, purple and white. After a genetic cross, the ratio of plants with purplepj-h+jx fbhu6du/kmr 3 :z+o+ 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 d)hm.prry32 )4gqmi90gkse s in London in 1991.p 0 qmkgr9)s)g3sri4dem2 yh.

  Which of these traits is an example of c,tu 96: ew 3h9+ vkr+fkfildw tkp:mg/ontinuous variation?

  Which row correctly describes diploid and haploiv jyblm l (prw+:agh6rq0 m(0 1;,jaxid cells in humans?

  The following table shows the diploid chromosome number of 1n*0 8copjc kla range of species.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessive allele ju-o xknq143 y(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 Avd *pbh. ln7/ uxf+gkmafo6 73 had a child with blood type O. What are the possible genotypes of the biologicap/f*d3ahvng m6kob +7u.f x7l l father?

  Which row shows the correct annotation of the alleles for blozhi tw48 ,r-buod groups?

  Which of these statements are as3 zy 8xni+f/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 s rj( 77t,otvung6 njj7ickle cell anaemia and the spread of malaria across the continent of Afutn nj,ro7 j jg76(v7trica.


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 nu vf.m2zkn+rs* mber of genes. Brown colour (B) is dominant to sandy colour (b) ands2fzrvm* +nk. 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 unlz7hwnv*,hlgyc . 3 :nvinked genes.

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

Sickle cell anaemia is 7w) kxvn wl7t km+l wrql70i83caused 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 ca8 g3mzc bf7z2ht that is homozygous for brown, long hair and a female cat tz23cbfz7 m hg8hat has black, short hair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the allele for diamond,loob.nf6/g(ie1 jfgr )7eay-shaped seeds (D) is dominant over ov,y en gi./(aljeofg1or )f6b 7al-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 (lr -c) s,v4sk)umjeaw kv. ;hj9), and curly hair (C) is dominant to straight hair (c). A test cross ua ;k jcrk49hvs,)sm) -we j.vwas 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 inheritancgizp1rkv mlbu6+2*1i ty u e-+e of the condition shown in the pedigree chart below it*+l g1-b +ky6u1rvi emupz2?

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

  Which of these statements about genetic disorders is/are correct9vdh/0 uj+4ub3bmt zi?

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 polygeku 3c4akp l 23t-y0oolnic traits 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 inheritan o3 6/j 4 rlqiyb gtmv4l:73nz,)uxvczce of the disorder shown in the pedigree chart is X-linked recessive and not autosomal recessive?: ic j4 ozv3ut4 g6/r7mvlyq,l bzxn)3

  Different species of living orgav6ae v v*g0nvf+2;xoz nisms have different numbers of genes characteristic te 2+xvv avo*ng;z vf06o 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 flxmp hx2 l;d z3 hb.e2szk+e d3+us)8tqower colour. If the pea plants Mendel was studying can only be white or purple and follow the rules of Mendelian genetics, which of these statements was com ;dsz.2b 8xeels)2ut z +ph3qdhxk+3rrect?

  A biological male with hemophilia 6(txcme2 y p7nfm7u5w and a biological female without hemophilia have a daughter without hemophilia. What are the possiblen( 2yx7 wcme7pf6t5u m genotypes of the daughter?

  A dihybrid cross was carried out between two sunflowe )np /6*ajvcfu0b w(fdr plants (Helianthus annuus) to see if the genes for seed number and seed shape are linkec6f )p ad*v(fwubj0 n/d. 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 0,ojcdiu;b x2can have a child with blood type cid;2x0jou,b O.

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

3.Explain the role of inheritance in genetic diseases.