Theme 2d

Question 1

What happens in the G1 and G2 phases

Answer 1

Synthesis of proteins, RNA, metabolites and other DNA
Duplication of chromatids and centrioles between phases

Question 2

What happens in the s phase

Answer 2

DNA replication

Question 3

What happens in the M phase

Answer 3

Mitosis

Question 4

What happens in cytokinesis

Answer 4

Cell division

Question 5

What is the G0 phase

Answer 5

Resting phase, exits cell cycle

Question 6

What does progression of the cell cycle depend on

Answer 6

Activation of cyclin-dependant kinase

Question 7

What are the 3 check points of the cell cycle

Answer 7

1) G1/S (DNA damage checkpoint)
2) G2/M (DNA replication checkpoint)
3) M (mitotic spindle checkpoint)

Question 8

What is an oncogene

Answer 8

Positive regulators of cell cycle (gain of function)
Gene amplification

Question 9

What is a tumour suppressor gene

Answer 9

Negative regulators of cell cycle (loss of function)

Question 10

What are homologous chromosomes

Answer 10

Maternal and paternal pair of chromosomes
Have the same number and order of genes but alleles are different

Question 11

Mitosis look at textbook

Question 12

What happens in binary fission

Answer 12

-begins at origin
-cell elongated and bacterial chromosome separates
-cell splits in half
-mitosis evolved from this

Question 13

After meiosis how are the chromosomes attached

Answer 13

By a protein structure called the synaptonemal complex

Question 14

What happens after meiosis one (reductional division)

Answer 14

Number of homologous pairs of chromosomes is reduced from 2 in the parental cell to 1 in the daughter cell (haploid but 2 chromatids per chromosome)
Sister chromatids are not identical due to crossing over

Question 15

What happens during mitosis 2

Answer 15

Same as mitosis 1 but centromere and sister chromatids separate during anaphase 2
Result is 4 cells with haploid number of chromosomes (1 chromatid per chromosome that are not identical) due to crossing over and random assortment

Question 16

Germline vs somatic mutations

Answer 16

Germline: inherited (occurs in gametes)
Somatic: not inherited (occurs in any other cell)

Question 17

What is a base substitution mutation

Answer 17

Single nucleotide change

Question 18

What is an insertion mutation

Answer 18

One or more base pairs added in sequence during DNA replication resulting usually in a frame shift mutation

Question 19

What is a deletion mutation

Answer 19

One or more base pairs skipped during replication (frame shift mutation)

Question 20

What is the difference between transition and transversion mutations

Answer 20

Transitions: purine to purine or pyrimidine to pyrimidine
Transversions: purine to pyrimidine or pyrimidine to purine

Question 21

What is a missense mutation

Answer 21

Causes a change in amino acid

Question 22

What is a nonsense mutation

Answer 22

Sense codon changes into a stop codon

Question 23

What is a silent mutation

Answer 23

Codon change doesn’t change amino acid

Question 24

What is a frameshift mutation

Answer 24

Insertion or deletion of base pairs that changes the reading frame

Question 25

What is a large scale deletion mutation

Answer 25

Loss of genes

Question 26

What is a duplication/amplification mutation

Answer 26

Increasing dosage of genes

Question 27

What is a translocation mutation

Answer 27

Interchange of genetic parts from non homologous chromosomes

Question 28

What is an inversion mutation

Answer 28

Reversing orientation of a segment of the chromosome

Question 29

What are base analogs

Answer 29

Mimic bases and incorporates into DNA (can cause mispairing during replication)

Question 30

What is the wildtype allele

Answer 30

Normal form of the gene

Question 31

Loss of function vs gain of function mutant alleles

Answer 31

LOF: reduce/eliminate gene function/expression GOF: enhance gene expression

Question 32

What is an allele

Answer 32

Different forms of a gene (sequence variation)