dna and mitotic cycle

Question 1

semi-conservative replication

Answer 1

each time DNA is replicated half of the original molecule is kept in each new molecules

Question 2

steps of DNA replication

Answer 2

1 unwinding, dna helices breaking hydrogen bonds
2 dna polymerase for copying process adding nucleotides
3 leading strand replicated continuously in 3’ to 5’
lagging strand replicated discontinuously in 5’ to 3’ direction In short sections making Okazaki fragments

Question 3

nucleotides are joined by

Answer 3

phosphodiester bonds

Question 4

what phase does dna replication occur in

Answer 4

s phase

Question 5

rna polymerase is used in

Answer 5

transcription

Question 6

what are Okazaki fragments joined by

Answer 6

DNA ligase

Question 7

purines

Answer 7

double ring structure
adenine
guanine

Question 8

semi conservative replication is good because

Answer 8

it ensure genetic continuity between generations

Question 9

lagging strand

Answer 9

runs in the 5’ to 3’ direction

Question 10

transcription

Answer 10

1 rna polymerase attaches to start of gene and unwinds gene
2 template/transcribes strand is copied
3 nucleotides approach and hydrogen bond with complementary bases +phosphodiester bonds to growing mrna hydrogen broken
mana leaves through nuclear pore

Question 11

translation

Answer 11

tuna transfer amino acids to ribosome anticodon on tRNA complementry to codon

Question 12

modifying mrna

Answer 12

rna processing
rna splicing removes introns and exons joined together
introns help dna regulate activity of genes

Question 13

alternative splicing

Answer 13

results in different Mrnas ebbing made from original primary transcript meaning. that one gene can code for several proteins or diff forms of same protein

Question 14

gene mutation

Answer 14

change in sequence of bases can result in different sequence of amino acid

Question 15

chromosome mutation

Answer 15

Chromosome structure mutations are alterations that affect whole chromosomes and whole genes rather than just individual nucleotides. These mutations result from errors in cell division that cause a section of a chromosome to break off, be duplicated or move onto another chromosome.

Question 16

stop codons

Answer 16

UAG, UAA, UGA

Question 17

start codon

Answer 17

AUG amino acid methionine

Question 18

2 things in early prophase

Answer 18

nuclear envelope breaks down
chromosome condense

Question 19

2 things in late prophase

Answer 19

chromosomes migrate to opposite poles of cell
spindle fibres from

Question 20

2 things in metaphase

Answer 20

chromosomes line up along equator
spindle fibres attach to kinetochores

Question 21

kinetochore

Answer 21

protein structure found at centromere where microtubules attach

Question 22

3 things in anaphase

Answer 22

chromatids separate
spindle fibres attach to centrosome
poles of cell move apart

Question 23

3 things in telophase

Answer 23

chromosomes begin to uncoil
nuclear envelope reforms
spindles disappear

Question 24

telomere

Answer 24

a repetitive sequence of DNA at the end of a chromosome that protects genes from the chromosome shortening at each cell division

Question 25

oncogene

Answer 25

mutated gene that has the potential to cause cancer.

Question 26

transcription

Answer 26

genetic code on DNA is copied into mRNA;
double helix of DNA unwinds (in region to be copied); complementary nucleotides line up along coding strand of DNA; A to U and C to G;
assemble together to make a complementary strand of mRNA; under influence of RNA polymerase;
mRNA unzips from DNA template and passes to ribosomes;

Question 27

translation