DNA

Question 1

What are the universal features of all cells in terms of DNA?

Answer 1

1. Hereditary information is stored in DNA as a nucleotide sequence.
2. DNA is replicated by the template-directed polymerisation- make ‘life’ possible.
3. Sections of DNA are transcribes into RNA, which carries the information to make proteins.
4. Proteins are predominantly used as catalysts (RNA catalysts also exist)
5. Proteins are produced by translation of RNA
6. Basic mechanism of translation is the same, including tRNA and ribosomes.

Question 2

What is the central dogma?

Answer 2

The central dogma is a flow chart representing the flow of hereditary information in a cell. DNA is replicated, transcribed to RNA and RNA is translated to protein. It fails to describe that information can flow from RNA to DNA.

Question 3

How many bases in each human cell?

Answer 3

3 billion

Question 4

Is the size of DNA related to complexity of the organism? Does it relate to the number of genes?

Answer 4

No. Newts, amoeba and some plants have more bases in each cell than humans do. No.

Question 5

What is the smallest genome?

Question 6

How many genes do humans have?

Answer 6

20 000-25 000

Question 7

How much of the human genome encodes for protein?

Answer 7

2%

Question 8

Whats an example of a highly conserved gene?

Answer 8

Gene coding for cytochrome C- important for generation of ATP during ETC in mitochondria.

Question 9

What are pseudogenes?

Answer 9

Inactive variants of genes that arose as a result of mutation which prevent functional expression of gene product. They may still recombine with related active genes to form novel genes or deletion derivatives.

Question 10

What is satellite DNA?

Answer 10

Perfect or near perfect tandem short repeats (

Question 11

What are mobile DNA sequences?

Answer 11

DNA elements which can replicate themselves and move around the genome. Include transposons and retrotransposons.

Question 12

What is microsatellite DNA?

Answer 12

1-14 bp long DNA units repeated in tandem up to 10 times.

Result of replication errors and can exist within genes. Changes in repeat number can lead to disease.

Question 13

What is minisatellite DNA?

Answer 13

14-500bp length units repeated in tandem hundreds of times.

Used in DNA fingerprinting.

Question 14

What kind of chromosome does mitochondria have and how many?

Answer 14

One circular chromosome.