Biology - DNA and Division

Question 1

Prokaryotes

Answer 1

Prokaryotes are simple cells. They do not have membrane bound organelles, which means there is no nucleus - the DNA is free in the cytosol (not enclosed)

Question 2

Eukaryotes

Answer 2

Eukaryotes are complex cells. They have many miniature compartments called membrane bound organelles which are inside their cells and perform various jobs.
Celles in the Animal, Plant, Fungi, Protista kingdoms are eukaryotes.

Question 3

DNA

Answer 3

DNA - Deoxyribonucleic acid
To encode a detailed set of plans for building different parts of the cell. The DNA molecule comes in a shape called a ‘double helix’ which is a twisted ladder.

Question 4

Gene

Answer 4

Genes are instruction manuals for our bodies. They are the directions for building all the proteins that make our bodies function. Made of DNA.

Examples of proteins which are built:
Hemoglobin, pigment enzymes, keratin

Question 5

Chromosome

Answer 5

Chromosomes are compact units into which DNA is packed.
In a human, there are 46 chromosomes organised into two sets of 23 chromosomes.
Sex chromosomes determine gender. ie. XY - Male, XX - Female

Question 6

Proteins

Answer 6

Proteins are vital to all living things as they control the characteristics of an organism.
They are a sequence of amino acids and the different order of amino acids leads to a protein with a different shape. The different shapes give the proteins different functions.

Question 7

Protein Synthesis

Answer 7

1. Messenger RNA synthesised alongside DNA strand in nucleus
2. Messenger RNA passes out of nucleus into cytoplasm
3. Messenger RNA becomes attached to ribosomes
4. Amino acids drawn into position by tRNA molecults

Question 8

Nucleotide

Answer 8

The basic unit of DNA: phosphate, sugar and nitrogenous base

Question 9

Transcription

Answer 9

Copying of a section of DNA into mRNA

Question 10

Translation

Answer 10

Creating of a polypeptide (protein) due to joining of specific amino acids coded for by codons of mRNA. tRNA is involved.
Occurs in the cytoplasm.

Question 11

Purpose of mRNA

Answer 11

To take the genetic information for a protein from the nucleus to the ribosomes

Question 12

Codon

Answer 12

3 bases on mRNA

1 codon = 1 amino acid

Question 13

Mutation

Answer 13

It is a change in the DNA code

Question 14

Four kinds of bases

Answer 14

A - adenenine
T - thymine
C - cytosine
G - guanine