Monohybrid inheritance — Paper 1 · IGCSE Sciences - Co-ordinated (Double) 0654

12 Cystic fibrosis is an inherited disease. Only people who are homozygous recessive, ff, suffer from this disease. Which cross could not give rise to a child suffering from cystic fibrosis? A FF x ff B Ff x Ff C Ff x ff D ff x ff

1 marks

Answer: A

This question in 0654/11 May/June 2005

11 Cystic fibrosis is an inherited disease. The diagram shows the occurrence of this disease in a family. 1 parents key = normal = cystic fibrosis offspring sufferer 2 If B represents the normal allele and b the allele for cystic fibrosis, what are the genotypes for 1 and 2? individual 1 individual 2 A bb bb B Bb bb C Bb Bb D BB Bb

1 marks

Answer: B

This question in 0654/11 Oct/Nov 2006

12 The diagram shows the results of crossing two tall pea plants. T represents the dominant allele for tallness. T t T TT Tt t Tt tt What information can be obtained from this diagram? A The parent plants were heterozygous. B All the offspring are homozygous. C The shaded row shows the phenotypes of the parents. D The right hand column shows mutations.

1 marks

Answer: A

This question in 0654/11 May/June 2007

12 Cystic fibrosis is an inherited disease. Only people who are homozygous recessive, ff, suffer from this disease. Which cross could not give rise to a child suffering from cystic fibrosis? A FF × ff B Ff × Ff C Ff × ff D ff × ff

1 marks

Answer: A

This question in 0654/11 Oct/Nov 2008

11 Black coat colour in mice is dominant to white coat colour. A pure-bred black mouse mates with a white mouse. What colour are the offspring? A black only B black and white C grey D white only

1 marks

Answer: A

This question in 0654/11 May/June 2009

11 The allele for red hair is recessive. If a girl has red hair, which statement about her parents must be correct? A Both parents must carry a recessive allele. B Both parents must have red hair. C One parent must carry a dominant allele. D The father must have red hair.

1 marks

Answer: A

This question in 0654/11 May/June 2010

5 The allele for red hair is recessive. If a girl has red hair, which statement about her parents must be correct? A Both parents must carry a recessive allele. B Both parents must have red hair. C One parent must carry a dominant allele. D The father must have red hair.

1 marks

Answer: A

This question in 0654/12 May/June 2010

12 The alleles for a particular character are H and h. Which term describes an organism whose genotype is Hh? A heterozygote B homozygote C phenotype D recessive

1 marks

Answer: A

This question in 0654/11 Oct/Nov 2010

9 The alleles for a particular character are H and h. Which term describes an organism whose genotype is Hh? A heterozygote B homozygote C phenotype D recessive

1 marks

Answer: A

This question in 0654/12 Oct/Nov 2010

9 The alleles for a particular character are H and h. Which term describes an organism whose genotype is Hh? A heterozygote B homozygote C phenotype D recessive

1 marks

Answer: A

This question in 0654/13 Oct/Nov 2010

11 The diagram shows the results of a breeding experiment using black and white mice. 1 2 × 3 × 4 Which statement is correct? A Mouse 1 has a dominant allele for fur colour. B Mouse 2 is heterozygous for fur colour. C Mouse 3 is homozygous for fur colour. D Mouse 4 is heterozygous for fur colour.

1 marks

Answer: A

This question in 0654/11 May/June 2012

11 In plants, the allele for red flowers is dominant to the allele for white flowers. A heterozygous red-flowered plant is crossed with a white-flowered plant. What percentage of the offspring will have red flowers? A 25 % B 50 % C 75 % D 100 %

1 marks

Answer: B

This question in 0654/12 May/June 2012

11 In plants, the allele for red flowers is dominant to the allele for white flowers. A heterozygous red-flowered plant is crossed with a white-flowered plant. What percentage of the offspring will have red flowers? A 25 % B 50 % C 75 % D 100 %

1 marks

Answer: B

This question in 0654/13 May/June 2012

11 In mice, the allele for black fur is dominant to the allele for white fur. Two heterozygous mice mate. What colour are the offspring likely to be? A all black B some black and some white C all grey D all white

1 marks

Answer: B

This question in 0654/11 Oct/Nov 2013

9 In mice, the allele for black fur is dominant to the allele for white fur. Two heterozygous mice mate. What colour are the offspring likely to be? A all black B some black and some white C all grey D all white

1 marks

Answer: B

This question in 0654/12 Oct/Nov 2013

13 The diagram shows the results of mating a male mouse that has black fur with a female mouse that has white fur. × If the allele for black fur is dominant, what do the results show? A The female parent is heterozygous. B The male parent is heterozygous. C The offspring with black fur are homozygous. D The offspring with white fur is heterozygous.

1 marks

Answer: B

This question in 0654/12 May/June 2014

12 Cystic fibrosis is an inherited disease. Only people who are homozygous recessive, ff, have this disease. Which cross could not give rise to a child suffering from cystic fibrosis? A ff × ff B Ff × ff C Ff × Ff D FF × ff

1 marks

Answer: D

This question in 0654/11 Oct/Nov 2014

10 Cystic fibrosis is an inherited disease. Only people who are homozygous recessive, ff, have this disease. Which cross could not give rise to a child suffering from cystic fibrosis? A ff × ff B Ff × ff C Ff × Ff D FF × ff

1 marks

Answer: D

This question in 0654/12 Oct/Nov 2014

12 Cystic fibrosis is an inherited disease. Only people who are homozygous recessive, ff, have this disease. Which cross could not give rise to a child suffering from cystic fibrosis? A ff × ff B Ff × ff C Ff × Ff D FF × ff

1 marks

Answer: D

This question in 0654/13 Oct/Nov 2014

12 Which cross results in all possible offspring having the same genotype? A BB × Bb B BB × bb C Bb × Bb D Bb × bb

1 marks

Answer: B

This question in 0654/11 May/June 2017

6 In a plant, the allele for red flowers is dominant to the allele for yellow flowers. A heterozygous red-flowered plant is crossed with a homozygous yellow-flowered plant. Which statement about the offspring is correct? A 25% will have red flowers, 75% will have yellow flowers. B 50% will have red flowers, 50% will have yellow flowers. C 75% will have red flowers, 25% will have yellow flowers. D 100% will have red flowers, 0% will have yellow flowers.

1 marks

Answer: B

This question in 0654/13 May/June 2017

4 In a species of plant, the allele for yellow flowers is dominant to the allele for red flowers. Two heterozygous yellow-flowered plants are crossed. Which offspring are produced? A 25% with yellow flowers, 75% with red flowers B 50% with yellow flowers, 50% with red flowers C 75% with yellow flowers, 25% with red flowers D 100% with yellow flowers

1 marks

Answer: C

This question in 0654/13 Oct/Nov 2017

11 A man breeds small mammals in which the fur colour is black or white. The allele for white is dominant to black. If he chooses a pair of heterozygous white mammals to breed together, which proportion of the offspring mammals will be black? A none of them B about a quarter C about half D all of them

1 marks

Answer: B

This question in 0654/12 Oct/Nov 2018

11 In pea plants, the allele for purple flowers is dominant to the allele for white flowers. Two heterozygous purple-flowered plants are crossed. What will be the expected flower colour of the offspring plants? A all purple B all white C 1 purple : 1 white D 3 purple : 1 white

1 marks

Answer: D

This question in 0654/13 Oct/Nov 2018

11 A pure-breeding mouse with black fur was bred with a pure-breeding mouse with white fur. All the offspring had black fur. What are the genotypes of the two parent mice? A Bb × bb B Bb × Bb C BB × bb D BB × BB

1 marks

Answer: C

This question in 0654/13 Oct/Nov 2019

11 In some plants the red flower allele is dominant to the yellow flower allele. Two heterozygous red flowered plants are crossed. Which statement about the offspring produced is correct? A 25% of plants will have red flowers, 75% will have yellow flowers. B 50% of plants will have red flowers, 50% will have yellow flowers. C 75% of plants will have red flowers, 25% will have yellow flowers. D 100% of plants will have red flowers.

1 marks

Answer: C

This question in 0654/11 May/June 2020

11 In cats, the allele for short hair is dominant to the allele for long hair. Two long haired cats are bred together. What hair length will the offspring have? A all long haired B all mid length hair C all short haired D 50% long and 50% short haired

1 marks

Answer: A

This question in 0654/13 May/June 2020

11 Which term is used to describe an individual with two of the same allele for a characteristic? A genotype B heterozygous C homozygous D phenotype

1 marks

Answer: C

This question in 0654/11 Oct/Nov 2020

11 Cystic fibrosis is an inherited condition caused by a recessive allele. A man and woman have a child who has cystic fibrosis. Neither parent has the condition. What is the probability of their next child also having cystic fibrosis? A 0% B 25% C 50% D 75%

1 marks

Answer: B

This question in 0654/11 May/June 2021

11 In a species of flowering plant, the allele for red flowers is dominant to the allele for white flowers. A plant breeder crossed a homozygous white-flowered plant with a heterozygous red-flowered plant. What is the expected phenotypic ratio of the next generation of plants? A 1 white : 1 red B 3 red : 1 white C 3 white : 1 red D all the plants will be red

1 marks

Answer: A

This question in 0654/12 Oct/Nov 2021

11 Two parents with genotypes of BB and Bb were crossed. Which genotypes and ratios would be expected in the offspring? A 1 BB : 1 Bb B 1 Bb : 1 bb C 3 BB : 1 Bb D 3 Bb : 1 BB

1 marks

Answer: A

This question in 0654/13 Oct/Nov 2021

11 Purple flower colour is dominant to white flower colour. Which parents must be crossed to make sure all the offspring have white flowers? A homozygous dominant  heterozygous B homozygous dominant  homozygous dominant C homozygous recessive  heterozygous D homozygous recessive  homozygous recessive

1 marks

Answer: D

This question in 0654/11 May/June 2022

11 Which diagram correctly shows sex inheritance in humans? A B male gametes male gametes X X X Y Y XY XY X XX XY female female gametes gametes Y XY XY Y XY YY C D male gametes male gametes X Y Y Y X XX XY X XY XY female female gametes gametes X XX XY X XY XY

1 marks

Answer: C

This question in 0654/13 Oct/Nov 2022

11 What is the correct term for an allele that is always expressed in the phenotype if it is present? A dominant B heterozygous C homozygous D recessive

1 marks

Answer: A

This question in 0654/12 Feb/March 2024

11 Albinism is a genetic condition which results in an absence of pigment in the skin, hair and eyes. If two black mice produce an albino offspring, which Punnett square shows the correct cross? A B B b B b B BB Bb B BB Bb B BB Bb b Bb bb key B dominant allele for black C D b recessive allele for albinism B b b b b Bb bb b bb bb b Bb bb b bb bb

1 marks

Answer: B

This question in 0654/11 Oct/Nov 2024

11 In a plant, the allele for red flowers is dominant to the allele for yellow flowers. A heterozygous red-flowered plant is crossed with a homozygous yellow-flowered plant. Which statement about the offspring is correct? A 25% will have red flowers and 75% will have yellow flowers. B 50% will have red flowers and 50% will have yellow flowers. C 75% will have red flowers and 25% will have yellow flowers. D 100% will have red flowers and 0% will have yellow flowers.

1 marks

Answer: B

This question in 0654/12 Oct/Nov 2024

11 In a plant, the allele for red flowers is dominant to the allele for yellow flowers. A heterozygous red-flowered plant is crossed with a homozygous yellow-flowered plant. Which statement about the offspring is correct? A 25% will have red flowers and 75% will have yellow flowers. B 50% will have red flowers and 50% will have yellow flowers. C 75% will have red flowers and 25% will have yellow flowers. D 100% will have red flowers and 0% will have yellow flowers.

1 marks

Answer: B

This question in 0654/13 Oct/Nov 2024

11 Two parents with genotypes of BB and Bb are crossed. What is the predicted ratio of genotypes in the offspring? A 1 BB : 1 Bb B 1 Bb : 1 bb C 3 BB : 1 Bb D 3 Bb : 1 BB

1 marks

Answer: A

This question in 0654/12 Oct/Nov 2025

11 Two parents with genotypes of BB and Bb are crossed. What is the predicted ratio of genotypes in the offspring? A 1 BB : 1 Bb B 1 Bb : 1 bb C 3 BB : 1 Bb D 3 Bb : 1 BB

1 marks

Answer: A

This question in 0654/13 Oct/Nov 2025