Paper 2 - Topic 3 : Inheritence

Question 1

What does DNA stand for ?

Answer 1

DNA = DeoxyriboNucleic Acid

Question 2

What does structure does DNA have ?

Answer 2

It has a double-helix structure

Question 3

How is DNA structured ?

Answer 3

DNA has two sugar-backbones, with two paired bases in the middle.

Question 4

What are the 4 bases in DNA ?

Answer 4

A - Adenine
T - Thymine
C - Cytosine
G - Guanine

Question 5

What are Genes ?

Answer 5

Genes = small sections of DNA that code for a sequence of amino acids that make up a protein

Question 6

What are Alleles ?

Answer 6

Alleles = different form of the same gene (for the gene eye colour, you have alleles of blue, brown, green, grey)

Question 7

What is a Genome?

Answer 7

Genome = the entire genetic make-up of an organism

Question 8

What are Genes ?

Answer 8

Genes = small sections of DNA that code for a sequence of amino acids that make up a protein

Question 9

What bases compliment what ?

Answer 9

Adenine - Thymine
Guanine - Cytosine

(At The ~ Group Chat)

Question 10

What is RNA ?

Answer 10

A smaller copy of a specific part of the DNA

Question 11

What is mRNA and tRNA ?

Answer 11

mRNA - Memory Ribonucleic acid
tRNA - Transport Ribonucleic acid

Question 12

How does the Ribosomes use RNAs to synthesis protein ?

Answer 12

It make a small copy of the DNA (mRNA) that tell it how to make protein , then the tRNA retrieves Amino Acids to help make the protein .

Question 13

Define Mitochondria

Answer 13

Mitochondria = the site of aerobic respiration

Question 14

Of which parent do they get their mitochondrial DNA from ?

Answer 14

Everyone gets their mitochondrial DNA from their mum - from the mitochondria in the egg cell (as only nucleus from paternal DNA becomes part of the offspring)

Question 15

What are the benefits of Sequencing the genomes of bacteria and viruses ?

Answer 15

Sequencing the genomes of bacteria and viruses allow us to discover the causes of diseases and lets us choose the right treatment

Question 15

Does Mitochondria has its own DNA ?

Answer 15

yes

Question 16

3 reasons the genome matter ?

Answer 16

Reasons the genome matters:
1.helps us understand inherited disorders like cystic fibrosis and sickle cell disease
2. helps predict the risk for each individual of developing any of these inherited disorders
3. Understanding it helps us learn more about evolution and history –> family trees can be traces using genome sequencing

Question 17

How to remember which bases are complimentary to each other using a mnemonic ?

Answer 17

A
T
Creams
Gants Hill

Question 18

What happens during Protein Synthesis?

Answer 18

Protein Synthesis:
1. Genes produce a template for protein–> reflects the sequence of bases in DNA but is small enough to leave the nucleus via the nuclear pores
2. Template leaves the nucleus and binds to the surface of the ribosome
3. Cytoplasm has carrier molecules each attached to an amino acid –> these attach to template in the order given by the DNA
4. Amino acids are joined together to form a specific protein
5. Carrier molecules continue bringing specific amino acids in the correct order until the template is completed
6. Protein sequence detaches from the carrier molecules which detaches from the template to pick up more amino acids
7. Completed protein chain folds up to form a unique shape to help carry out its function

Question 19

What does it mean when a gene is expressed ?

Answer 19

When a gene codes for a protein that is synthesised in the cell, the gene is said to be expressed

Question 20

Define Phenotype

Answer 20

Phenotype = the physical appearances or biochemistry of an organism

Question 21

Do mutations change the protein that forms ?

Answer 21

Most mutations don’t change the protein that forms, OR they alter the protein so slightly that its appearance and function don’t change

Question 22

What is relationship between mutations in the non-coding part of the DNA and the phenotype ?

Answer 22

Mutations in the non-coding part of DNA do not directly affect the phenotype

Question 23

In what way could changes in the non- coding part of the DNA affects genes ?

Answer 23

HOWEVER, changes in the non-coding part of DNA can affect which genes are switched on or off - by changing which genes are expressed, this can impact our phenotype

Question 24

Is DNA is polymer or monomer ?(If Polymer what are its monomers called and consists of )

Answer 24

Polymer - Its monomers are nucleotides - base and a sugar and a phosphate
The backbone of the DNA = sugar phosphate backbone

Question 25

What do genes code for ?

Answer 25

Genes code for proteins

Question 26

What is an impact of mutation ?

Answer 26

A mutation in even one group of bases can affect the protein’s structure and so can detriment its ability to carry out its function

Question 27

What is are alleles ?

Answer 27

Alleles = different forms of the same gene

Question 28

Define Recessive

Answer 28

Recessive = is only expressed in the phenotype in the absence of a dominant allele

Question 29

Define Dominant

Answer 29

Dominant = expressed in the phenotype whether it’s only one, or both

Question 30

Define Homozygotes

Answer 30

Homozygotes = an individual with the same alleles for a characteristic

Question 31

Define Heterozygotes

Answer 31

Heterozygotes = an individual with different alleles for a characteristics