Genetics and Inheritance

Question 1

Non disjunction

Answer 1

Occurs when chromosomes fail to separate properly during meiosis, resulting in gametes with an abnormal number of chromosomes (either too many or too few). Can lead to conditions such as down syndrome and turner syndrome.

Question 2

Random assortment

Answer 2

During meiosis chromosomes are randomly distributed into daughter cells. Each gamete receives a random mix of maternal and paternal chromosomes. Leading to numerous potential genetic combinations in the offspring.

Question 3

Random fertilization

Answer 3

Fertilisation involves the union of a sperm and an egg, each carrying a unique set of chromosomes. Which sperm fertilises which egg is a random event. Each gamete has different genetic material due to meiosis, creasing genetic diversity in the population.

Question 4

Mutations

Answer 4

Permanent changes in the DNA sequence that can occur spontaneously or due to environmental factors (e.g., radiation, chemicals). They can affect a single gene, a segment of a chromosome, or entire chromosomes. Introduces new alleles into a population, creating new genetic traits that may be advantageous, neutral, or disadvantageous.

Question 5

ABO Blood groups inheritance pattern

Answer 5

Autosomal codominant

Question 6

Red green colour blindness inheritance pattern

Answer 6

X-linked recessive

Question 7

Haemophilia inheritance pattern

Answer 7

X-linked recessive

Question 8

Huntington’s disease inheritance pattern

Answer 8

Autosomal dominant

Question 9

5. Phenylketonuria (PKU) inheritance pattern

Answer 9

Autosomal recessive

Question 10

Epigenetics

Answer 10

The study of changes in gene expression or cellular phenotype that do not involve alterations to the underlying DNA sequence. Instead, these changes are caused by chemical modifications to the DNA molecule or associated proteins, which can turn genes on or off or adjust their activity levels.