DNA Lesson 6.1 Genetic Variation

• Biologie
• Middelbare school
• vwo
• Leerjaar 4

Review of transcription and translation

After I have given you the answer, be sure to write down the answers of the questions for yourself!

Answers:

D24: No also inside the mitochondria (and for plants chloroplasts)

D25: It is stored in the nucleus, because there is too much genetic information 

D26: 23 pairs so 46 chromosomes

D27: The structure and visible appearance of chromosomes changes during the phases of the cell cycle as the chromosomes become more or less compacted.

D28: Genes. Genes can vary in length 

D29: A sequence of DNA called the promoter, found near the beginning of a gene

D30: 1. Template strand 2. Coding strand

D31:  1. 5' --> 3'   2. 3' --> 5' 

D32: Ribosomal proteins

D33: There are 64 different codons: 61 specify amino acids and 3 are used as stop signals.

D34: 1. AUG 2. Methionine 3. TAC

D35: 1. Peptide bond 2. peptide

       Cancer being caused by mutagenic factors

Mutagenic radiation

DNA change influenced by radiation

Chemical substances

Virus

                          Cancer

Normal cell division is regulated by:

- tumor suppressor genes: Encode for proteins that inhibit cell     division

- proto-oncogenes: Encode for proteins that stimulate cell            division

Together they regulate a balanced cell division

                           Cancer

Origin of cancer:

- mutation in suppressor gene: cell division is out of

   control

- mutation in proto-oncogene: becomes oncogene so cells keeps dividing

A tumor develops after multiple mutations in one cell

Cancer cells: cells gone wrong after a mutation

Cell proliferation

Uncontrolled cell division

The development of cancer

Proto-oncogene --> mutation/exte gene expression --> oncogene

--> extra cell growth and extra cell division --> tumor suppressor gene --> apoptosis (cell death) 

If the cell doesn't die -->

TUMOR

Cancer causing genes are called ________.

1. transformation genes
2. tumor suppressor genes
3. oncogenes
4. mutated genes

Benign tumors  are capsulated, slowly growing and non-invasive

Malignant tumors spread, grow rapidly and are invasive

Metastasis!

                 Benign vs. malignant

Homework

Work on worksheet lesson 5

Work on worksheet lesson 6 (for now only 39 - 42)

00:18

Is all genetic material present in the nucleus?

00:18

Why is the genome stored in the nucleus?

00:24

How many chromosomes?

23 pairs so 46 chromosomes

00:32

Do they always look like this, the chromosomes?

00:41

What is it exactly that we see here?
Is it all the same size?

00:52

Where does RNA polymerase exactly attach? How is this called?

a sequence of DNA called the promoter, found near the beginning of a gene

00:59

What is the name of the single strand of DNA where the mRNA is being made on? And what is the name of the complementary strand?

Template strand

Coding strand

01:00

1. What is the direction of the mRNA synthesis?
2. What is the direction of the DNA strand that is being read?

01:46

What are ribosomes made of?

02:04

If there are 20 amino acids and 4 basepairs. How many different codons are there?
How does this work?

There are 64 different codons: 61 specify amino acids and 3 are used as stop signals.

02:08

What is the first codon of the mRNA that is being read?
What is the first amino acid that is connected to the tRNA?
What is the codon of this tRNA?

02:18

What are the bonds that are being formed between the amino acids?
How do we also call the molecule that is being formed?