2. Cells, DNA & Genes

The Cell Cycle:

The Cell Cycle:

1) Interphase – Cells grow and prepare to divide

2) Mitosis – cells start to divide

3) Cytokinesis - two cells are formed from one

Chromosome

Chromosome

• Thread-like structure made mostly of DNA, found in the nucleus of a cell.

DNA –

DNA

• Material found in the nucleus that contains genetic information

Gene -

Gene

• A segment (part of) DNA that controls protein production.

Chromosomes come in what form?

From what?

● Humans → ? pairs (? Chromosomes)

● butterfly → ? pairs (? chromosomes)

● Ant → ? pair (? chromosomes)

Chromosomes come in pairs one set from Father (50%) and the other from Mother (50%)

● Humans → 23 pairs (46 Chromosomes)

● butterfly → 190 pairs (380 chromosomes)

● Ant → 1 pair (2 chromosomes)

Down Syndrome result of?

Down Syndrome

• (Result of an extra chromosome)

deoxyribonucleic acid: ?

Also called?

found in?

• DNA: Also called deoxyribonucleic acid,

• is material found in the cell nucleus

• that contains genetic information

A stands for ?

C stands for ?

T stands for ?

G stands for ?

Note: ACTG are also known as?

(the ‘colours ‘that make up the DNA)

A stands for Adenine

C stands for Cytosine

T stands for Thymine

G stands for Guanine

• ACTG are also known as nitrogen bases or nucleotides

Codons are ?

Ex. ?

• Codons are 3 letter words that are a Code for which protein is to be produced.

Ex. CAT, GAG, TAG

• If there is a mistake in the genetic code this is what is known as a? _______

Eg. ?

If there is a mistake in the genetic code this is what is known as a

_____Mutation___

Eg. Vitiligo (Change of the pigment in your skin)

How do Mutations Occur?

• The changes of ACTG in DNA can change for ?

How do Mutations Occur?

The changes of ACTG in DNA can change for?

• no reason at all / unknown reasons.

• Or due to damage

Mutagens: ?

Mutagens:

• A substance of factor that can cause a mutation in DNA, where DNA is physically damaged.

Key Difference

Mutations = ?

Mutagens = ?

Examples of mutagens: ?

Key Difference

Mutations = the changes

Mutagens = the causes

Examples of mutagens: UV radiation, X-rays, certain chemicals, some viruses.

Cloning : ?

Pros: ?

Cons: ?

Cloning :

• The process of creating identical genetic copies of an organism

Pros:

• You make copies of ‘superior’ / ‘desireable’ organisms (Animals or Food)

Cons:

• May be less resistant to disease