SCIENCE B2 REVISION

Flash cards & more!

PLEASE NOTE THAT THIS PRESENTATION DOESN’T HAVE EVERYTHING IN B2! Some topics are left out.

DNA

Located in the nucleus for plant/animal cells. Found in chromosomal DNA and plasmid DNA for bacterial cells.

Genes are just sections of chromosomes which code for specific proteins.

DNA has a double helix structure.

DNA Nucleotide / Mono nucleotide

Phosphate group

Deoxyribose sugar / pentose sugar

Base

Has 5 carbons.

Click me!

State two ways in which the structure of this yeast cell differs from the structure of a bacterial cell. (2 marks)

Make sure you read the question well. In this one, we can only list two points.

Model Answer:

“A bacterial cell generally has a flagellum and it doesn’t have a nucleus like a yeast cell.”

You don’t need to write much, since it’s only for two marks and it’s asking you to plainly state two points.

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CHROMOSOMES DNA

More specific, allows particular traits

Strands of chromosomes

Proteins make up most of your body.

Except bone; that is made out of calcium.

What does the term “magnification” mean?

The distance of zooming in on an

object

High magnification

No magnification

What is the resolution?

The clarity and quality of an image from a microscope

More things on DNA that you should know…

This is how a DNA Nucleotide/mono nucleotide

is drawn.

Err, mayor… what’s that?

Ohh, right! How

interesting, mayor!

What’s the maximum magnification of a modern telescope?

2,000,000 times

How do you calculate the actual length of an object?

Length of magnified object

Magnification

Example = length of magnified object is 87mm, and the magnification is 2100.

87/2100 = 0.042

How do you calculate the length of a magnified object?

Length of object

Magnification

Example = length of object is 87mm, and the magnification is 2100.

87*2100 = 170100

*

What is a characteristic of genetic engineering?

It produces a unique set of

genes.

What does enucleation mean?

Removal of a nucleus.

What’s the first stage of copying a DNA strand?

Translation

Which four bases are present in mRNA?

ACGU

Where’s mRNA made?

Nucleus

Where does the mRNA get made?

Ribosomes

Where does the mRNA move in order to be read?

Ribosomes

What’s the name of the long chain of amino acids that’s formed?

Polypeptide

What’s another name for enzymes?

Biological catalysts

BasesI’m all about that base, ‘bout that

base, no (pentose) sugar…

You must memorize four bases:

• Adenine• Thymine• Guanine• Cytosine

The bases all pair up to a particular base. (OTP!!!)

A x TC x G

A joins up with T, C joins up with G. You must remember this. This is the case for DNA, but not RNA (if RNA isn’t in this presentation, you’re on

your own, bud).