genetics and Mutations

Question 1

Where is DNA in a cell?

Answer 1

The Nucelus

Question 2

What is DNA?

Answer 2

DNA is genetic information for an organism.
- Deoxyribonucleic Acid.

Question 3

What is the structure of DNA?

Answer 3

A double Helix - like a ladder, it is double stranded

Question 4

Describe the relationship between chromosomes, DNA and genes.

Answer 4

There are 46 chromosomes inside a human nucleus
DNA makes up the chromosomes
Chromosomes contain genes that determine the traits of an organism
A gene is a segment of DNA that codes for a specific protein

Question 5

What is a nucleotide?

Answer 5

A molecule that is the basic building block of the nucleic acids DNA and RNA. It is made up of a phosphate group, a deoxyribose sugar and a base

Question 6

What are the 4 bases in DNA? What base pairs with what?

Answer 6

Adenine + Thymine and Cytosine + Guanine

Question 7

What bonds hold together the bases in DNA?

Answer 7

Hydrogen bonds

Question 8

What is protein synthesis?

Answer 8

How genes make a protein, using:
Transcription (DNA → mRNA)
Translation (mRNA → protein)

Question 9

Describe each step of protein synthesis.
What is involved?
Where does this occur in the cell?

Answer 9

Transcription is the process of when RNA is synthesised from a DNA template,
Translation is when RNA is used to assemble amino acids into a protein at the ribosome.

Question 10

How is mRNA paired with DNA?
What are the bases?

Answer 10

mRNA is paired with DNA the same apart form that thymine is now Uracil. So if a DNA template was A,T,C,G the matching pairing that mRNA would produce would be U,A,G,C.

Question 11

What is mRNA?

Answer 11

mRNA stands for messanger RNA.
mRNA carries the instructions for one gene
mRNA is synthesised in the nucleus
Its function is to make a copy of a gene and take it to a ribosome, where amino acids are assembled to make a protein

Question 12

What is the role of the ribosome?

Answer 12

Synthesizing proteins by translating the genetic code transcribed in mRNA into an amino acid sequence

Question 13

What is a polypeptide chain? How is this different to a protein?

Answer 13

a polypeptide is a chain of many amino acids; and a protein contains one or more polypeptides. Proteins are long chains of amino acids held together by peptide bonds.

Question 14

What is tRNA?

Answer 14

tRNA stands for Transfer RNA

Question 15

What is the role of tRNA?

Answer 15

it serves as a link between the messenger RNAmolecule and the growing chain of amino acids

Question 16

How to transcribe DNA to mRNA.

Answer 16

The enzyme that converts DNA into mRNA is called RNA polymerase

Question 17

What is a triplet, codon and anticodon?

Answer 17

A triplet is a sequence of three nucleotides that determines one amino acid.

A codon is the triplet of a set of nucleotides in DNA that codes for an amino acid.

The triple base complement for a codon is called an anticodon

Question 18

Be able to translate mRNA to amino acids using the codon table. - What comes first

Answer 18

AUG COMES FIRST

Question 19

What is a mutation? Different types of mutations

Answer 19

Mutations are changes in genetic material:

Question 20

When do mutations occur?

Answer 20

Errors in DNA replication
They may be induced by mutagens (environmental factors that cause changes in DNA).

Question 21

Give examples of Mutagens

Answer 21

X-rays/radiation
Chemicals, poisons
UV light
Viruses

Question 22

How do mutations impact protein synthesis?

Answer 22

By changing a gene’s instructions for making a protein, a variant can cause a protein to malfunction or to not be produced at all