A man and a woman have a daughter and a son. To 8b yg-cle- 8s.mw/umheir daughter has normal vision, but their son is colourblind. /8 wu .lbgcme ms-y-8oWhich one of these genotypes could be correct for the biological mother?

  Which diagram shows the sex chromosomes of a somatic cell i:4q g gbf:l9fk3kicfq -b n1.xn a human male?

  There are two alleles for flower col+)gc0dk7kibm8ts ew ) our in snapdragons. However, the result of a cross between two heterozyg0tks7d)igkb+ w 8)cemous 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 to48/2 qwbzgza:ub3ep 7defk k) the correct definition?

  Which of these statements in(tw,7+x eu8mpssx2k0)njlea p oqj*t9r: .x s a correct definition for a gene?

  The diagram shows a pair of homologolw oa1wxh l pzq;(i7)+us chromosomes.

How many loci are shown?

  Two individuals, heterozygous for a specific trait, were crossed in an nm/( 5bcmt*f zgrui0-+t-zhg experiment. Which row shows the expected phenotypic ratios of the offsprinz m(+hm-gn *0 tibu/ rt5cfgz-g resulting from this cross?

  In some animals, the agouti allele causes individual hairs to have a banded pat1jiownouc2 u am)28,pa29f tetern. The non-agouti allele causes hairs to be a st2ua8u oi1 nf2p)ema2w jc o9,ingle 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 ingr ud30-nd8 yidividual pea plants was either round or wrinkled. The results of an experimental cross yielded 315 offspring with- i0dnugy83 rd 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 //v3)-dq 8 xo9jree nh6wkdqo fly (Drosophila melanogaster) have 8 chromosomes. How many chromosomes are in a fertilised oocyte of a fruit fly?o d d kq)e8 oje9wn-/xv36hqr/

  When does the random orientation of homologous chromosome pairs ( * pdwvo9dx8zoccur?

The majority of the genes in the human genome have already been mapped, meaningfg/db5b kt 26ssj iz31 the exact locatio3b5k2jib /tf1s6gdz sns 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 linked genes?r 15rtk:b) :enkhe.y m

  The diagram shows a kda c* g61w5wqlx.7 udjaryogram of a brown male rat (Rattus norvegicus). Which arrow is pointing to a pair of autocx5 lugq67dj a1.w* wdsomes?

  Mendel observed that there are two poss7hf- 3 j+dzpnnible variations of flower colour in pea planf +dnz3 -ph7jnts, 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 parents?

  The graph shows the frequency of birth weight of children born in London in 19wtu9i fpp6 b5)91 p wt9ip5f6)bu.

  Which of these traits is an example of continuouybfrbpn*5 + 6er0w 7uts variation?

  Which row correctly de;p s oyfk.-x)sscribes diploid and haploid cells in humans?

  The following table shows the diploid chromosome number of a range of spex1057 uum7hke2cvcl rf 2)qb tcies.

Which of these statements is correct?

  Sickle cell anaemia is caused by a recessiveko pa1iqi o5f1szq 2b9n3j) 8s 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 typ 2evqn84y,j5rhxgsi,y, q yc/e O. What are the possible genotypes of the biological father? yg,s/cxqv ,i4, nq5jhy r2y8e

  Which row shows the correct annotn;j1z 7f6xd h bo4bg;f4.fhbk+cm 6o eation of the alleles for blood groups?

  Which of these statements vg:, bywn:jb,d )i 4rl7ly o4ncoa o*6are 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 cell anae28)ya ekht1hz mj .oi/ly)q c+mia and the spread of malaria across the continent of Afrl 8)ckehity+2ah ./ ojy1 m)zqica.


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 begvui8 q s5e1b7:k-lgy a number of genes. Brown colour (B) is dominant to sandy colour (b) and an ombre (two tone) colour (P): s iveuq-le1g k5bg87 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 lj8mr - ijq.s5qinked and unlinked genes.

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

Sickle cell anaemia is caused by the allele7aor7vlr vi93snwrwr+ku/ c)85 lxx, 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 v f n4n2jzh27;.d mjewthat is homozygous for brown, long hair and a female cat that has black, short hjvz42;nd2j fn.mh w7 eair.


Which of the offspring has a recombinant genotype?

  In dandelions (Taraxacum officinale), the u9( qgoko8pq6u+ ,px hallele for diamond-shaped seeds (D) is dominant over oval-shaped seeds (dkuoou98 6qqp pg+( ,hx) 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 xvms phrt9x3* (;hzh5wj9fp7h+/vbuto short hair (l), and curly hair (C) is dominant to straight hair (c). A test cross was carried out between male heterozygous long,phu xvh tf5rb99mhspw3jz/v 7 *x ;(h+ 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 inkhf z, +/dg+ty1+db8abtj ( bplyh,g3heritance of the condition shown in the pedigree chart belowpydzbt hkf+/b3 gt+81hblydj +a( ,g,?

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

  Which of these statements a +1*mb 4v7i3mqob iardbout 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 normah:p w)vqbs)j rd,un8cd,h-c5l 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 itxknu+4 8;vgv-wmu;m p( iel*n the pedigree chart is X-linked recessive and not autosomal recessive(v8upm x lgk; nmw4 -vu;t*i+e?

  Different species of living organisms have different numbers of g-z(xgf ( u;0xy ip90ec, huvgzmr,7 yrenes characteristic 7 (r,r u9;-z0xgxgvyez f phi,(myuc0to 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 cu.xje bwa +vt0(wib87 haracteristics of pea plants, including flower colour. If the pea plants Mendel was studying can only be white or purple and (+j0buav.w7twb 8x iefollow the rules of Mendelian genetics, which of these statements was correct?

  A biological male with hemophilia and a biological female without hemophilia havfg wrs:,pd) 2;ileg z/ ip(oj78+ ycaze a daughter without hemophilia. What are the possible genotypes of (a/ 2: wde8iz, gp7ji+ ;rfgcpsyz)lothe daughter?

  A dihybrid cross was carried out between two sunflower plantsfch a 9nbs6c; )bjbv s*2a2.wk (Helianthus annuus) to see if the genes for seed numbw)j sb*k9 2; nabf.2vhaccs b6er 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 this indicate?

1.Explain how parents with blood type A and blood type572vv5jw+db; 4vdfxa,vl xa e B can have a child with blood txvbafej,d 5vx;v v2wa57+d l4 ype O.

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

3.Explain the role of inheritance in genetic diseases.