Biology 6.1.5

Question 1

DNA is a ___ - a Molecule Made from Many Repeating Subunits.

Answer 1

Polymer.

Question 2

What are the Individual Subunits of the Polymer DNA Called?

Answer 2

Nucleotides.

Question 3

Each Nucleotide Consists of a Common… (3)

Answer 3

-A Common Sugar.

-A Phosphate Group.

-1 of 4 Different Bases Attached to the Sugar.

Question 4

What are the 4 Different Bases for Nucleotides? (4)

Answer 4

-Adenine (A).

-Cytosine (C).

-Thymine (T).

-Guanine (G).

Question 5

The Bases on Each Strand Pair Up with Each Other, Holding the 2 Strands of DNA in the ___ ___.

Answer 5

Double Helix.

Question 6

The Bases Always Pair Up in the Same Ways: (2) This is Known As…

Answer 6

-Adenine Always Pairs Up with Thymine (A-T).

-Cytosine Always Pairs Up with Guanine (C-G).

This is Known As ‘Complementary Base Pairing’.

Question 7

A Sequence of ___ Bases is the Code for a Particular Amino Acid.

Answer 7

3.

Question 8

The Phosphate & Sugar Section of the Nucleotides form the ___ of the DNA Strand.

Answer 8

Backbone.

Question 9

It is the Sequence of ___ that Holds the Code for the Formation of Proteins.

Answer 9

Bases.

Question 10

Where are Proteins Made in the Cells?

Answer 10

Ribosomes.

Question 11

What do Ribosomes Use to Make Different Proteins?

Answer 11

Ribosomes Use the different Sequence of Bases to Make Specific Proteins.

Question 12

DNA Cannot Travel Out of the Nucleus to the Ribosomes; it is too Big. So What Happens?

Answer 12

The Base Code of Each Gene is Transcribed Onto an RNA Molecule Called Messenger RNA (mRNA).

Question 13

Explain the Full Process of ‘Protein Synthesis’: (5)

Answer 13

-Certain Gene of the DNA in the Nucleus is Chosen that makes the Specific Protein that is Wanted.

-mRNA Comes & Copies it. Complimentary Bases. No T Base in mRNA. A -> U. G -> C. etc.. OG Gene is Left in the Nucleus.

-mRNA, now with the Complimentary Copy of the Chosen Gene, travels through the Cytoplasm. Enters Ribosome.

-Depending on the Bases Present on the mRNA, Specific tRNA with Complimentary Bases will Attach on. Happens in Groups of 3 (Codons). Each tRNA has a Specific Amino Acid Attached to the Other End.

-So Based on the OG Base Series on the Gene in the Nucleus, the Complimentary Copy on the mRNA goes to the Ribosome, then tRNA Makes a Complimentary Copy of that Base Series, in Groups of 3, so now it is back to the OG Base Series. Each tRNA has a Specific Amino Acid on the End. So, Based on the tRNAs that were just Used, a Unique Series of Amino Acids will join together, therefore making the Unique, Specific, Needed, Protein.

Question 14

A Change in DNA Structure May Result in a Change in the…

Answer 14

Protein Synthesised by a Gene.

Question 15

If there is a Change in the Order of the Bases in a Gene, then a Different ___ May be Produced.

Answer 15

Protein.

Question 16

The Ribosome ‘Reads’ the Code on the mRNA in Groups of ___. Each Triple of Bases Codes for a Specific ___ ___.

Answer 16

3, Amino Acid.

Question 17

Proteins can Be: (3)

Answer 17

-Enzymes.

-Hormones.

-Structural Proteins.

Question 18

What are ‘Mutations’?

Answer 18

Mutations are Random Changes that Occur in the Sequence of DNA Bases in a Gene or Chromosome.

Question 19

Mutations Occur ___.

Answer 19

Continuously.

Question 20

As the DNA Base Sequence Determines the Sequence of Amino Acids that Make Up a Protein, Mutations in a Gene can Lead to…

Answer 20

A Change in the Protein that the Gene Codes for.

Question 21

There are 3 Different Ways that a Mutation in the DNA Base Sequence can Occur: (3) Explain them.

Answer 21

-Insertions: A New Base is Randomly Inserted into the DNA Sequence.

-Deletions: A Base is Randomly Deleted from the DNA Sequence.

-Substitutions: A Base in the DNA Sequence is Randomly Swapped for a Different Base.

Question 22

Insertion & Deletion Mutations have a ___ ___ Effect. What does this mean?

Answer 22

Knock-On. They will Change the Groups of 3 Bases Further on in the DNA Sequence.

Question 23

Substitution Mutations do not Cause a ___ ___ Effect.

Answer 23

Knock-On.

Question 24

Most Mutations do not Alter the…

Answer 24

Protein.

Question 25

Not All Parts of DNA Code for Proteins. Some Non-Coding Parts of DNA can Switch Genes ___ & ___. This means that they can Control whether or not a Gene is…

Answer 25

On, Off. Expressed.

Question 26

The Polymer DNA is Made of Repeating Subunits of…

Answer 26

Nucleotides.

Question 27

DNA is a Double-Stranded Polymer of Molecules Called…

Answer 27

Nucleotides.

Question 28

The ___ Sequence of a Gene Determines the ___ ___ Sequence of the Protein.

Answer 28

Base, Amino Acid.

Question 29

What is a ‘Mutation Knock-On Effect’?

Answer 29

When a Mutation has a Knock-On Effect, the Mutation will also Affect the Groups of 3 Bases further on.