Biology 0610 · IGCSE
Chromosomes, genes and proteins
100 practice questions on Chromosomes, genes and proteins, with worked solutions and instant marking.
What substance is specified by a length of DNA?
Feb/March 2016
What does the term alleles mean?
Feb/March 2016
What does the term alleles mean?
Feb/March 2016
The diagram illustrates the sex chromosomes of a woman and a man. Their genotypes for a recessive sex-linked condition are also given. What is the likelihood that their daughter will have the sex-linked condition?
Feb/March 2016
The diagram illustrates a section of DNA, with four bases marked on one strand. Which sequence of bases would appear on the opposite strand, beginning at the top?
Feb/March 2016
What does the term chromosome mean?
Feb/March 2016
A frog species new to science was found in 2009 in the Amazon rainforest in Peru. Fig. 6.1 depicts this frog, Osteocephalus castaneicola.
Feb/March 2016
Which term refers to the passing of genetic information from one generation to the next?
Feb/March 2017
What does the term gene mean?
Feb/March 2017
Which sex chromosomes in the egg and the sperm would result in a male child?
Feb/March 2018
Two animals possess the same amino acid sequence in one of the proteins in their cells. What does this suggest about these animals?
Feb/March 2018
Which sex chromosomes in the egg and in the sperm must combine to produce a male child?
Feb/March 2018
What is the term for a length of DNA that codes for a protein?
Feb/March 2019
What is the correct meaning of a gene mutation?
Feb/March 2019
The statements explain how a protein is synthesised. What is the sequence of statements that correctly explains how a protein is synthesised?
Feb/March 2020
This photomicrograph displays some red blood cells. Which genotype combinations might this person have?
Feb/March 2020
What term is used for ‘a thread-like structure of DNA, carrying genetic information in the form of genes’?
Feb/March 2021
How would you define ‘a thread-like structure of DNA, carrying genetic information in the form of genes’?
Feb/March 2021
The statements below show stages in protein synthesis. 1 Copies of the gene are moved to the cytoplasm as mRNA molecules. 2 Each ribosome links amino acids together to make a protein molecule. 3 The gene that codes for a protein is copied in the nucleus. 4 The mRNA molecules move through ribosomes. Which order of steps is correct?
Feb/March 2021
On one strand of a DNA molecule, the bases are arranged in the order CAGCT. What base sequence is found on the complementary strand?
Feb/March 2021
Which statement concerning the synthesis of a protein molecule inside a cell is correct?
Feb/March 2023
In humans, what genotype does a red-green colour-blind male have?
Feb/March 2023
Within DNA, which bases form the correct pairs?
Feb/March 2023
Which human phenotype is determined only by genes?
Feb/March 2024
Fruit flies may have either red eyes or white eyes. This is a sex-linked characteristic, and the gene controlling eye colour is found on the X chromosome. The allele for red eyes ($R$) is dominant over the allele for white eyes ($r$). A fruit fly with genotype $X^R X^r$ was crossed with a fruit fly with genotype $X^R Y$. What percentage of the offspring will have red eyes?
Feb/March 2024
Which term refers to a length of DNA that codes for a protein?
Feb/March 2025
What term describes a length of DNA that codes for a protein?
Feb/March 2025
Which of the following statements about the sex chromosomes is correct?
Feb/March 2025
A segment of a chromosome has $4500$ bases. It includes $1450$ G bases. What is the number of A bases present?
Feb/March 2025
Which structure is present in the nucleus of a body cell in a woman?
May/June 2016
What does the term mutation mean?
May/June 2016
People who own race horses that perform well hope the young will resemble their parents. In what way does a young race horse acquire its characteristics by inheritance?
May/June 2016
When bases pair during the formation of DNA, what is one example of a base pairing?
May/June 2016
In the nucleus of a woman’s body cell, which structure is present?
May/June 2016
Owners of race horses that perform well expect their foals to resemble their parents. In what way does a young race horse acquire its characteristics?
May/June 2016
The diagram presents the sequence of bases along part of one DNA strand. A-C-T-T-A-G-A-T What base sequence is found on the matching section of the opposite strand?
May/June 2016
Cat sex is determined in the same way as human sex.
May/June 2016
The diagram illustrates the formation of a human fertilised egg cell that develops into a male. Which row shows the sex chromosomes in the cells?
May/June 2017
What do genes encode?
May/June 2017
Each cell in an alligator’s nose contains 32 chromosomes. How many chromosomes would an alligator zygote have?
May/June 2017
Which diagram illustrates the structure of DNA?
May/June 2017
Which row gives the description of the genetic code found in DNA?
May/June 2017
Colour blindness is a condition that happens more often in men than in women. Which statement about this condition is correct?
May/June 2017
Four stages in protein production are shown below. 1. An mRNA copy of the gene is made. 2. The mRNA moves into the cytoplasm. 3. The mRNA attaches to a ribosome. 4. The ribosome joins amino acids together to form a protein molecule. In what order do these events usually take place?
May/June 2017
Which statement concerning the sex chromosomes is correct?
May/June 2017
One strand of a DNA molecule has the base sequence shown: A-A-T-C-T-G. What base sequence would be found on the complementary strand?
May/June 2017
Researchers are examining the structure and role of genes.
May/June 2017
The diagram illustrates how sex is inherited in humans. What is the probability that the couple’s next child will be male?
May/June 2018
What factors will make the mutation rate increase?
May/June 2018
Which chromosomes are present in one sperm cell?
May/June 2018
A segment of DNA contains the instructions for making a protein. What term is being defined here?
May/June 2018
The diagram illustrates the chromosomes present in the nucleus of a somatic cell from an adult fruit fly. What are the fruit fly’s diploid and haploid chromosome numbers?
May/June 2018
The diploid chromosome number in $\textit{Ovis aries}$ (sheep) is $54$. How many chromosomes would a zygote of this species have?
May/June 2018
Which human characteristics are passed on genetically?
May/June 2019
What decides whether a baby is male or female?
May/June 2019
Which option is a genetic change?
May/June 2019
A human zygote is a diploid cell. Which statement concerning human diploid cells is correct?
May/June 2019
What is the name for the passing of genetic information from one generation to the next?
May/June 2021
Through which process is genetic information passed from one generation to the next?
May/June 2021
The diagram presents a brief segment of one DNA strand. Which DNA strand would pair with this strand to make part of a double helix?
May/June 2021
The table presents a section of DNA from four different organisms. Which two organisms are furthest apart in terms of relatedness?
May/June 2021
A zygote contains ten chromosomes in its nucleus. Which row gives the number of chromosomes in the cells of this species?
May/June 2021
Which molecule transports a copy of the gene into the cytoplasm so that a protein can be made?
May/June 2021
Colour blindness is a sex-linked characteristic. Which of the following statements about colour blindness is correct?
May/June 2021
The arrangement of bases on one strand of a DNA molecule is shown: ATTGGACGGT. Which sequence gives the bases on the other strand?
May/June 2021
The bonobo and the chimpanzee are two species that are very closely related. What is the most precise way to determine how closely related species are?
May/June 2021
The Tasmanian devil is an animal whose body cells contain seven pairs of chromosomes. The diagram illustrates the chromosomes present in one cell from a Tasmanian devil. Which statement is correct?
May/June 2021
A DNA sample was analysed to determine which bases it contained. 35% of the bases in the DNA were G. Which row gives the percentages for the remaining bases?
May/June 2021
Which statement correctly describes a gene mutation?
May/June 2021
Insulin is a protein produced by cells in the pancreas. Fig. 2.1 illustrates how insulin is synthesised in a pancreatic cell.
May/June 2021
The horse, $\textit{Equus ferus}$, and the donkey, $\textit{Equus asinus}$, can interbreed. Their offspring is known as a mule. Which statement is correct?
May/June 2022
The shape of a bird’s beak is determined by genes inherited from parent birds by their offspring. What example is this?
May/June 2022
A student used a diagram to describe the inheritance of sex in humans. Which statements should she choose to fill boxes 1 and 2?
May/June 2022
The diagram illustrates sex inheritance in humans. A male and a female have one daughter. What is the probability that their next child will be female?
May/June 2022
Which sex chromosomes in the egg cell and in the sperm would result in a female child?
May/June 2022
What is required in the cytoplasm for proteins to be made at a ribosome?
May/June 2022
In a DNA segment, 20% of the bases were T. What percentage of the bases is G in this DNA segment?
May/June 2022
A chromosome was examined and was found to contain 6125 pairs of bases. The base type at each position was identified, and 2345 of the bases were G. How many of the bases in this chromosome are T?
May/June 2022
Bacteria share the same genetic code with which kingdoms?
May/June 2022
DNA consists of .....1..... strands twisted around one another. The strands contain chemicals known as .....2..... . These chemicals join to form .....3....., with A pairing with T and C pairing with G. Which words correctly fill gaps 1, 2 and 3?
May/June 2022
What term is used for a length of DNA that codes for a protein?
May/June 2023
Potatoes are examples of stem tubers. A tuber may be planted in the ground and develop into a new plant, and that plant can then produce many more tubers. The diploid number of the potato plant is 24. How many chromosomes will there be in the cells of the stem, the leaf and the pollen?
May/June 2023
The statements outline the sequence of events involved in protein synthesis. 1. mRNA moves through a ribosome. 2. mRNA molecules transport a copy of the gene into the cytoplasm. 3. The gene that codes for the protein is copied in the nucleus. 4. Ribosomes join amino acids together to form proteins. What is the order of statements that shows how a protein is made?
May/June 2023
DNA consists of two strands twisted around each other to make a double helix. Which base pairing between the two strands is correct?
May/June 2023
The stages below take part in protein synthesis. 1. amino acids joined together in sequence 2. mRNA travels into the cytoplasm 3. mRNA moving through a ribosome 4. DNA in the nucleus What is the correct order in which they are involved when proteins are made?
May/June 2023
A man with red-green colour blindness has a child with a woman who is not affected by red-green colour blindness. Their child is red-green colour blind. They plan to have another child. What is the percentage probability that their next child will be red-green colour blind?
May/June 2023
DNA is made up of base pairs. Which pair gives a correct base combination?
May/June 2023
What substance does a length of DNA code for?
May/June 2023
Which term refers to the structure of DNA?
May/June 2023
State the names of the structures labelled X, Y and Z in Fig. 5.1.
May/June 2023
Fig. 2.1 shows part of a DNA molecule in diagram form.
May/June 2023
What is meant by the term allele?
May/June 2024
Which statement concerning a heterozygous individual is correct?
May/June 2024
In one family, the two parents have blood groups A and B, and the three children have blood groups B, B and O. What are the genotypes of the parents?
May/June 2024
The diagram illustrates the bases in a section of DNA from only one strand. A-C-T-T-C-A-G-T-C. What base sequence would be found on the complementary DNA strand?
May/June 2024
Which diagram illustrates the correct pattern of sex chromosome inheritance?
May/June 2024
Which statements about the production of a protein are correct?
May/June 2024
What are different versions of genes known as?
May/June 2025
What do you call another form of a gene?
May/June 2025
Which statement gives a description of inheritance?
May/June 2025