Topic 16 - Inheritance A-level Biology

Jacob, Lily, and Samuel are studying genetics. They come across the letter 'A' in both chromosomes. What does this 'A' represent?

• genotype

• locus

Answer explanation

The A in both chromosomes represents the locus, which is the specific location of a gene on a chromosome.

Imagine Anaya, Chloe, and Oliver are in a science lab, studying DNA. They come across a segment of DNA that codes for a particular phenotype. What do they call this segment?

• genotype

• gene

Answer explanation

A segment of DNA that codes for a phenotype is called a gene. It determines specific traits or characteristics.

Chloe, Aiden, and Ethan are studying genetics. They come across a term 'Bb'. What does this term represent in genetics?

• It represents a recessive allele

• It represents a heterozygous condition

Answer explanation

The correct answer is 'heterozygous'. It refers to having two different alleles for a particular gene. In this context, 'heterozygous' is the correct choice because 'Bb' represents a heterozygous genotype.

Kiara and Oliver are having a debate. Kiara says alleles are different forms of the same gene, but Oliver thinks they are different cells. Who is correct, Kiara or Oliver?

• Kiara

• Oliver

Answer explanation

Alleles are different forms of the same gene. They represent variations in a gene's DNA sequence and can result in different traits or characteristics.

Imagine Isabella and Thomas are in a science lab, experimenting with pea plants. They cross a tall pea plant Tt with another tall pea plant Tt (Tt x Tt). Can you help Amelia predict the traits of the offspring plants?

• All of them will be short, 100% short

• Most of them will be tall, 75% tall, and some will be short, 25% short

Answer explanation

When a tall pea plant Tt is crossed with another tall pea plant Tt, the traits of the offspring are 75% tall and 25% short. This is because the dominant allele T for tallness is present in both parents, but the recessive allele t for shortness can also be inherited.

Imagine Emma, Addison, and Aiden are in a magical garden where they find a tall pea plant (TT) and a short pea plant (tt). They decide to cross these plants (TT x tt). Can you guess the traits of the baby plants that will grow?

• 75% of them will be tall, and 25% will be short

• All of them will be tall

Answer explanation

When a tall pea plant (TT) is crossed with a short pea plant (tt), all the offspring will be tall (100% tall).

Amelia, Priya, and Neha are having a debate. Amelia says the genotype is the genetic makeup of an organism, while Priya thinks it's the alleles gained from one parent. Who is correct?

• Amelia

• Priya

Answer explanation

The genotype refers to the genetic makeup of an organism, which includes the alleles gained from both parents. In this context, the correct choice is 'Genetic makeup'.

Imagine Aarav and Daniel are having a debate. Aarav says the phenotype is the physical appearance of an organism, while Daniel thinks it's the alleles acquired from a specific parent. Who is correct, Aarav or Daniel?

• Aarav

• Daniel

Answer explanation

The phenotype refers to the physical appearance of an organism, highlighting the correct choice.

Abigail, Arjun, and Aiden are playing a game of genetic bingo! They've come across a tricky question and need your help. What allele combination should fill their missing bingo box?

• AA

• Aa

Answer explanation

The missing box should contain the allele combination 'Aa'. This is the correct choice because it represents a heterozygous genotype with one dominant allele (A) and one recessive allele (a).

Imagine William, Ava, and Rohan are studying genetics. They come across an organism with the genotype of AaXx. They start debating about the types of gametes this organism can produce if the two genes are unlinked. Can you help them solve this puzzle?

• either AX, Ax, aX, ax

• either Aa or Xx

Answer explanation

An organism with the genotype AaXx can produce gametes containing either AX, Ax, aX, or ax if the two genes are unlinked. These combinations are possible due to independent assortment of alleles during meiosis.