Molecular basis of genetics

Question 1

Karyotype

Answer 1

ordered display of chromosomes

Question 2

Telomeres

Answer 2

The ends of a chromosome

Question 3

Kinetochore

Answer 3

The part of the chromosome that the spindle fibres attach to during metaphase

Question 4

What are the 5 stages of Mitosis?

Answer 4

Prophase, Prometaphase, Metaphase, Anaphase, Telophase

Question 5

What is the role of the centromere?

Answer 5

To act as a site of assembly of the kinetochore

Question 6

What are the differences between RNA and DNA

Answer 6

can exist as either single or double stranded, has uracil instead of Thymine and a hydroxyl group on C2 making it more reactive and susceptible to degradation

Question 7

What bonds link nucleotides together?

Answer 7

Phosphodiester bonds

Question 8

Histone

Answer 8

A protein that associates DNA in the nucleus and helps condense DNA into a smaller volume

Question 9

Chromatin

Answer 9

a complex of DNA and proteins that forms chromosomes within the nucleus of eukaryotic cells

Question 10

Euchromatin

Answer 10

less condensed and can be transcribed

Question 11

Heterochromatin

Answer 11

more condensed and typically not transcribed

Question 12

Nucleosome

Answer 12

The subunit of chromatin

Question 13

Histone octamer

Answer 13

8 histone proteins

Question 14

What is the charge of histone proteins?

Answer 14

Positive (made up of positive amino acids)

Question 15

Linker DNA

Answer 15

links two nucleosomes together

Question 16

Chromatin remodelling

Answer 16

When a cells chromatin ‘opens up’ to allow gene expression to take place

Question 17

ATP dependent chromatin remodelling

Answer 17

complexes restructures the nucleosome- requires energy

Question 18

Why do we need to control how DNA is used?

Answer 18

Different cells have different functions, an animal has different needs throughout their life and they need to adapt to their environment

Question 19

What are some examples of histone modification enzymes?

Answer 19

acetyl transferases, methyl transferases, kinases

Question 20

What does acetylation do?

Answer 20

activates the gene

Question 21

What does methylation do?

Answer 21

inactivates the chromatin

Question 22

epigenetics

Answer 22

inherited traits that do not represent a change in genetic information

Question 23

What are some amino acids with positive charges?

Answer 23

Lysine, Arginine

Question 24

What is mitosis?

Answer 24

When a cell splits into two genetically identical daughter cells

Question 25

where is histone H1 located?

Answer 25

in the nucleosome linker DNA

Question 26

What proteins are found in the nucleosome?

Answer 26

two copies of each of H2A, H2B H3 and H4

Question 27

What is a fibre formed from?

Answer 27

Nucleosomes folded around each other

Question 28

Which histone protein does fibre formation require?

Answer 28

H1

Question 29

What are chromatin fibres folded into?

Answer 29

loops

Question 30

what does HAT do?

Answer 30

removes the positive charge from lysine therefore making the histone neutral so it has less affinity for the sugar phosphate backbone

Question 31

What is the charge of a histone protein?

Answer 31

positive

Question 32

How long is each base pair?

Answer 32

around 0.34 nanometres long

Question 33

What is the unit of genetics?

Answer 33

The gene (length of DNA that contains the instructions to produce RNA and therefore a protein)

Question 34

Chromatosome

Answer 34

when linker DNA binds nucleosomes together

Question 35

What is the physical role of the centromere?

Answer 35

To act as a site of assembly for the kinetochore