Inheritance — IGCSE Biology (0610) questions by topic

What are alternative forms of genes called? A alleles B chromosomes C genotypes D phenotypes

What is an alternative form of a gene called? A allele B chromosome C genotype D protein

Cystic fibrosis is an inherited condition that occurs when an individual is homozygous for the recessive allele. If both parents are heterozygous for this characteristic, what is…

An individual has the genotype Bb. What is the correct description of this genotype? A heterozygous, with two different alleles of the same gene B heterozygous, with two different…

Which statement describes inheritance? A organisms which are not pure-breeding B the difference between homozygous and heterozygous genotypes C the genetic information in dominant…

A DNA molecule contains pairs of bases. What is a correct combination of a pair of bases? A A and G B C and A C G and T D T and A

The diagram shows the chromosomes in the nucleus of a cell that divides by mitosis. The parent cell nucleus contains six chromosomes (three pairs of differing shapes/lengths).…

A farmer bred together male cattle with white hair and female cattle with red hair. All the offspring produced had roan hair (a mixture of red and white). He then repeatedly bred…

Phagocytes and neurones are two types of specialised cell. Which statements are correct? 1 Phagocytes and neurones express the same genes. 2 Both types of cell have the same…

The diagram shows the inheritance of a genetic condition in one family across three generations. In the pedigree, affected individuals (both male and female) appear in each…

In a DNA molecule, bonds between pairs of bases hold two strands together. High temperatures can break these bonds to form two single strands of DNA. The base pair C and G is held…

Which name is given to different versions of a gene? A allele B chromosome C length of DNA D protein

The diagram shows the cells of a mammalian embryo shortly after fertilisation. [Diagram: a cluster of several similar cells (a ball of cells), each containing a nucleus, showing…

The diagram shows the inheritance, in one family, of a sex-linked recessive disease. [Pedigree diagram with key: circle = female, square = male; shaded = affected, unshaded =…

The melanin gene in humans codes for a pigment produced in the skin, hair and eyes. Describe what is meant by the term gene.

Fig. 3.1 is a pedigree diagram for a plant that can have either blue flowers or purple flowers. Blue flower colour is dominant to purple flower colour. The allele for blue flowers…

Meiosis and mitosis are important processes in the life cycles of organisms. Fig. 3.1 shows the life cycles of two different organisms. Organism 1 has a simple life cycle (adult…

Proteins are biological molecules. Explain how proteins are made.

Which sex chromosomes need to be present in a sperm cell to produce a male offspring? A X only B Y only C XX D XY

What do genes code for? A fats B proteins C starch D sugars

When white-flowered pea plants are crossed with red-flowered pea plants, the offspring plants all have red flowers. If these offspring plants are crossed, the next generation of…

Which sex chromosomes are present in a human sperm cell? A both X and Y chromosomes B either X or Y chromosomes C only X chromosomes D only Y chromosomes

What are alleles made of? A amino acids B DNA C genes D protein

Where are amino acids assembled into protein molecules? A the DNA B the genes C the nucleus D the ribosomes

The diagram shows the changes in the mass of DNA in one cell before, during and after mitosis, with point X marked where the mean mass of DNA per cell doubles. What is happening…

A woman who has blood group AB has a child with a man who has blood group B and is heterozygous. What is the chance of the child having blood group B? A 0% B 25% C 50% D 100%

Which base in a DNA molecule always pairs with a G base? A A B G C C D T

Why do different cells in a human body produce different proteins? A Alleles can be dominant or recessive. B Only particular genes are expressed. C Cells have different genes. D…

Which graph shows the mean mass of DNA per cell before, during and after mitosis? (mean mass of DNA per cell / arbitrary units against time, options A-D) A graph A B graph B C…

Which description of a human gamete is correct? A a diploid cell with 23 chromosomes B a diploid cell with 46 chromosomes C a haploid cell with 23 chromosomes D a haploid cell…

Which statements about meiosis are correct? (columns: produces genetically identical cells; involved in the production of gametes) A yes; no B yes; yes C no; yes D no; no

A female parent who is heterozygous for red-green colour blindness has a female child with a red-green colour-blind male parent. What is the chance of the female child being…

A pure-breeding plant with smooth stems was crossed with a heterozygous plant with hairy stems. What will be the ratio of hairy to smooth stems in the resulting plants? A 1 hairy…

The gene for red-green colour vision is on the X chromosome. There are two alleles for this gene: the allele for normal colour vision is represented by the letter B; the allele…

Fig. 5.1 is a pedigree diagram showing the inheritance of blood group in one family. State the number of people in Fig. 5.1 with: XY chromosomes; only one IA allele.

Some blood-clotting disorders can be inherited. Describe what is meant by the term inheritance.

What is defined as a length of DNA that codes for a protein? A amino acid B antibody C chromosome D gene

A man has three sons. What is the chance of his next child being a daughter? A 0% B 25% C 50% D 100%

Which human characteristics are inherited? Columns: blood group; eye colour; language; sex (key: ✓ = inherited, blank = not inherited). Which row A–D is correct? A B C D

When breeding, which pair of parents will be pure-breeding for a particular characteristic? A a heterozygous and a homozygous individual B two heterozygous individuals C two…

In a pea plant, the allele for round seeds, R, is dominant to the allele for wrinkled seeds, r. If plants with the genotype Rr are crossed, what are the likely proportions of…

Which statement is correct? A Chromosomes are made of DNA. B Chromosomes make up a gene. C Each chromosome is a length of DNA that codes for a protein. D Different forms of…

In a species of mammal, black fur colour is dominant and brown fur colour is recessive. Two parents with black fur produce offspring which all have black fur. Later that year, the…

The structure of DNA involves two strands coiled together to form a double helix. Which pairing of bases between the two strands is correct? A A and G B A and T C C and A D C and T

Potatoes are stem tubers. A tuber can be placed in the ground to grow into another plant, which can grow many more tubers (asexual reproduction shown over 4 months). The diploid…

The statements describe how a protein is made. 1 mRNA passes through a ribosome. 2 mRNA molecules carry a copy of the gene to the cytoplasm. 3 The gene coding for the protein is…

Which parents could produce offspring with blood group O? A heterozygous father with blood group A and heterozygous mother with blood group B B heterozygous father with blood…

The diagram shows the inheritance of albinism in one family. Albinism is an inherited condition caused by a recessive allele. The pedigree shows generations with unaffected…

DNA contains pairs of bases. Which pair shows a correct combination of bases? A A and C B C and G C G and A D T and G

The following are involved in protein synthesis. 1 amino acids assembled in order 2 mRNA moves to the cytoplasm 3 mRNA passing through a ribosome 4 DNA in the nucleus In which…

A man of genotype IᴬIᵒ and woman of genotype IᴮIᵒ have a child. What is the chance that the child will have the same blood group as one of its parents? A zero B 1 in 4 C 1 in 2 D…

A man who has red-green colour blindness has a child with a woman who does not have red-green colour blindness. The child has red-green colour blindness. The man and woman decide…

What describes the structure of DNA? A Each strand contains chemicals called fatty acids. B Each strand contains a sequence of amino acids. C Each strand contains mRNA. D Two…

Which substance is coded for by a length of DNA? A base B glucose C glycerol D lipase

The diagram shows the sex chromosomes of a woman (genotype XᴬXᵃ) and of a man (genotype XᵃY) for a recessive sex-linked condition (key: A is dominant, a is recessive). What are…

Which Punnett square shows a test cross that identifies a heterozygous parent? Each option A–D is a 2×2 Punnett square crossing a parent with gametes T/t or T/T against a…

Fig. 5.1 shows the stages involved in protein synthesis, with parts labelled X, Y and Z and amino acids being assembled. State the names of the parts labelled X, Y and Z in Fig.…

Fig. 2.1 is a diagram of part of a DNA molecule (a double helix with paired bases). Draw a circle on Fig. 2.1 to identify one pair of bases.

Which statement about the human sex chromosomes is correct? A Females have an X chromosome and a Y chromosome. B Females have two Y chromosomes. C Males and females have at least…

The inheritance of seed colour in pea plants is controlled by a single gene. The allele for yellow seed colour, Y, is dominant. The allele for green seed colour, y, is recessive.…

Two parents have the genotypes Bb and bb for a particular feature. What is the probability of these parents having offspring that are homozygous recessive for this feature? A 100%…

A genetic cross between two organisms may be shown as Tt × Tt. What does T represent? A a dominant allele B a dominant chromosome C a recessive allele D a recessive chromosome

A pea plant with the genotype YY is crossed with a pea plant with the genotype yy. What are the possible genotypes of the offspring? A YY and yy B all Yy C Yy and yy D all YY

The diagram shows part of a genetic diagram for the inheritance of sex in humans. The parents are father and mother; the father's gametes are X and gamete 1, and the mother's…

Which row shows correct information about mitosis? Columns: cells produced by mitosis (compared genetically with parent); number of chromosomes in the daughter cells compared to…

Polydactyly is a condition that can occur in cats, resulting in affected individuals having extra toes. The diagram shows the inheritance of the condition in a family of cats…

In guinea pigs, the allele for black fur is dominant and the allele for white fur is recessive. A test cross can be used to determine the genotype of a guinea pig with black fur.…

Why are cells in the pancreas the only body cells that produce insulin? A All of the genes in the nucleus of a cell in the pancreas are expressed. B Other body cells do not have…

Which statement is correct? A Mitosis always produces offspring that are homozygous. B Mitosis produces cells that are genetically identical. C Mitosis produces gametes in…

Red-green colour blindness is a sex-linked characteristic caused by a recessive allele. Which prediction can be made about the children of a woman who is colour-blind and a man…

Pea plants produce either yellow or green seeds. Yellow (Y) is dominant to green (y). What are the most likely phenotypes of the offspring of a cross between YY and Yy plants? A…

The diagram shows the chromosomes of a cell after they have replicated and just before the cell divides by mitosis. Which pair of cells will be produced at the end of mitosis?…

Which statements are correct descriptions of parts of the process of protein synthesis? 1 Amino acids are made by the ribosomes. 2 mRNA is copied. 3 The gene coding for the…

Mitosis and meiosis are both important processes for life. Complete the sentences about mitosis and meiosis. Mitosis is a type of nuclear division which produces genetically…