Unit 5.3 Genes and alleles

• Biologie
• Middelbare school
• vwo
• Leerjaar 2

Unit 5 

Heredity and evolution

Basic 3

Genes and alleles

DO YOU REMEMBER?

DNA

4 different bases (nucleotides)

cytosine

guanine

adenine

thymine

double helix (ladder)

information is stored in code

AATCCGGACGAATTCCGGAAAAAATTTTTTTTTTTTTTTTTTCGCGCGAATTCATATATATCGGACGGACGAACCGGAAAAAATTTTTTTCGCGCGAATTCATATATACCGGACGAATTCCGG..............

etc etc etc it would be a very thick book 

Gene: section of DNA with complete code for a protein

for example: gene for hair colour 

proteins

Lots of functions

E.g. enzymes, hormones, antibodies, cell structure

gene = code for 1 protein

Genes determine your characteristics

copying

you start with one fertilised egg with 46 chromosomes... (egg+sperm)

you end up with billions of cells with the same 46 chromosomes => all of them a copy from the original.....

during cell division the DNA has to be duplicated and sometimes things can go wrong during duplication, the DNA is different => mutations

from DNA code to proteins

3 bases = 1 amino acid

proteins are made up of amino acids. 

ACC is code for one kind of amino acid.

AAG is code for another kind of amino acid. 

21 different amino acids.

string of amino acids = protein

amino acids -> protein

Practice

Read paragraph 5.3

The molecule
shown in the
picture is called ...

1. DNA
2. single stranded DNA
3. an amino acid
4. a ribosome

This is a picture of ..

1. chromosome
2. gene
3. DNA
4. cell

Below are a few codes with 4 letters.
Which of these codes show a piece ofDNA?

1. ABCDBDCA
2. CAEFEAFC
3. GACTATGC
4. TACDDTAC

What do you call the part of a chromosome that carries the information for 1 heriditary trait?

1. DNA
2. a gene
3. a mother cell
4. an egg cell

Does the information for hereditary traits change when a cell is copied?

1. yes
2. no

this is a picture of ........

1. cell
2. chromosome
3. DNA
4. gene