Genetic Diseases

Question 1

What is genetics ?

Answer 1

Genetics is the study of heredity in general and of genes in particular

Question 2

What is heredity ?

Answer 2

Heredity: the passing of traits from parent to offspring (INHERITANCE)

Question 3

What is a phenotype ?

Answer 3

Phenotype: individual’s observable traits (such as height, eye colour, etc)

Question 4

What is a genotype ?

Answer 4

Genotype: the set of genes in our DNA which are responsible for a particular trait

Question 5

What is hybridisation ?

Answer 5

Hybridisation: Mating, or crossing, of two varieties

Question 6

What is true breeding ?

Answer 6

True breeding: When the plants self-pollinate, all their offspring are of the same variety

Question 7

What is monohybrid cross ?

Answer 7

Monohybrid cross: A cross between two parents that breed true for different versions of a single trait

Question 8

What did Mendel propose about inheritance ?

Answer 8

Mendel proposed that the inheritance of traits is governed by hereditary factors (which we now call genes)

Question 9

What is a genetic disease ?

Answer 9

A genetic disease is a disease that is caused by an abnormality in an individual’s DNA

Question 10

What are the 4 types of genetic disorders ?

Answer 10

1) Single gene defects

2) Chromosome abnormalities

3) Multifactorial disorders

4) Cancer (progressive accumulation of mutations in different genes and different chromosomes abnormalities, usually in somatic cells)

Question 11

What is a gene ?

Answer 11

Gene (unit of heredity) encodes the synthesis of a gene product, usually a protein (or RNA), according to its nucleotide sequences, following the genetic code

Question 12

What are missense mutations ?

Answer 12

These are base changes that alter the codon for an amino acid resulting in its replacement with a different amino acid

Question 13

What are nonsense mutations ?

Answer 13

Base changes that convert an amino acid codon to a stop codon, resulting in a premature termination of translation and the production of a shortened protein

Question 14

What are silent mutations ?

Answer 14

Silent mutations- do not cause any change in an amino acid

Question 15

What are frameshift mutations ?

Answer 15

Frameshift mutations = These mutations result from the insertion or deletion of one or more bases causing the alteration of the reading frame of the gene and a different set of codons, leading to an altered protein