Genetics and Genomics

Question 1

What is Genetics?

Answer 1

The study of how traits vary in a population and are passed from parent to offspring

Question 2

What is DNA comprised of?

Answer 2

Pairs of nucleotides (A sugar, phosphate and a base)

Question 3

What are the bases used in DNA? Which bases pair with which?

Answer 3

Adenine –> Thymine

Cytosine –> Guanine

Question 4

What is the main purpose of DNA molecules?

Answer 4

To contain instructions for the creation of functional proteins like a blueprint)

Question 5

What is a gene?

Answer 5

A sequence of base pairs that code for a specific trait

Question 6

What is the locus of a gene?

Answer 6

The physical location of a gene on a strand of DNA/Chromosome

Question 7

What is an allele?

Answer 7

Different DNA sequences for the same gene

Question 8

What is the difference between a dominant and recessive allele?

Answer 8

A dominant allele only requires one copy of the allele to be present in the genotype to be expressed, whereas recessive alleles require two copies of the allele to be present in the genotype to be expressed

Question 9

What is a wild type allele? What symbol is a wild type allele represented by? What symbol is a non-wild type/mutant allele represented by?

Answer 9

The “normal” allele and phenotype present in most individuals. It is represented by a “+” symbol. A non-wild type/mutant allele is represented by a “-“ symbol

Question 10

How is the information stored in DNA turned into functional protein?

Answer 10

The DNA sequence for the protein is first transcribed into a strand of mRNA, with uracil replacing thymine in the base sequence
The mRNA is then translated into amino acids, with each codon (3 amino acids) representing an amino acid in the polypeptide chain

Question 11

What is a genotype?

Answer 11

An individual’s combination of two alleles for a specific trait

Question 12

What does a homozygous genotype mean?

Answer 12

Both alleles in the genotype are the same

Question 13

What does a heterozygous genotype mean?

Answer 13

The alleles in the genotype differ from each other

Question 14

What is a phenotype?

Answer 14

The physical or chemical expression of a genotype

Question 15

What is phenotypic plasticity?

Answer 15

How much a phenotype is determined by environmental factors. Traits with high phenotypic plasticity can be easily affected by environmental factors, whereas traits with low phenotypic plasticity are not easily affected by environmental factors

Question 16

What is a monogenic trait? How can you tell that a trait is monogenic?

Answer 16

A trait where only one gene is involved in the trait. You can tell it’s monogenic if the variations on the trait are few and/or “one or the other”

Question 17

What is a polygenic trait? How can you tell that a trait is monogenic?

Answer 17

A trait where multiple genes are involved in the trait. You can tell it’s polygenic if the variations on the trait appear on a spectrum

Question 18

What is co-dominance?

Answer 18

When the two alleles in the genotype can be expressed at the same time (e.g. blood group alleles A and B)

Question 19

How can mutations occur?

Answer 19

Mutations can occur during DNA replication when mistakes are made or through exposure to ionising radiation

Question 20

What types of mutations can occur?

Answer 20

Point mutation (Single base change)
Insertion/Deletion mutations (Bases added or removed)
Copy number variations
Chromosomal abnormalities (Chromosomal deletion, duplications, Trisomy)