cell gentics

Question 1

Interphase/ Mitotic phase

Answer 1

Cell grows and carries on
its usual activities
mitotic phase: Cell divides into two

Question 2

three subphases

Answer 2

G1 (gap 1): vigorous growth and metabolism
S (synthetic): DNA replication occurs
G2 (gap 2): preparation for division

Question 3

DNA replication

Answer 3

the cell makes a copy of
DNA
Double-stranded DNA helices unwind and
unzip
Replication fork: point where strands
separate
Replication bubble: active area of
replication
Each strand acts as a template for a new
complementary strand
RNA starts replication by laying down short
strand that acts as a primer

Question 4

DNA polymerase

Answer 4

attaches to primer and
begins adding nucleotides to form new strand
DNA polymerase synthesizes both new
strands at one time

Question 5

End result

Answer 5

two identical “daughters”
DNA molecules are formed from the
original

Question 6

Mitosis

Answer 6

Prophase
Metaphase
Anaphase
Telophase

Question 7

Interphase

Answer 7

Dung interphase, nuclear material is in uncondensed chromatic state

Question 8

Semi conservative replication

Answer 8

Each new double- stranded DNA is composed of one old strand and one New strand

Question 9

Semi conservative replication

Answer 9

Each new double- stranded DNA is composed of one old strand and one New strand

Question 10

Early prophase

Answer 10

Chromatin condenses, forming visible chromosomes
•Each chromosome and its duplicate (called sister chromatids) are held together by a centromere
•Centrosome and its duplicate begin synthesizing microtubules that push each centrosome to opposite poles of cell

Question 11

Late prophase

Answer 11

Nuclear envelope breaks up
•Special microtubules attach to specific area on centromeres called kinetochore and serve to pull chromosomes to center of cell
•Remaining nonkinetochore microtubules push against each other, causing poles of cell to move farther apart

Question 12

Metaphase

Answer 12

Centromeres of chromosomes are precisely aligned at cell’s equator

Question 13

Anaphase

Answer 13

‘Centromeres of chromosomes split simultaneously—each sister chromatid now becomes a separate chromosome

Question 14

Telophase

Answer 14

chromosome movement stops
•Each set of chromosomes (at opposite ends of cell) uncoils to form chromatin
•New nuclear membranes form

Question 15

Cytokinesis final phase

Answer 15

Begins during late anaphase and continues through mitosis Two daughter cells are pinched apart

Question 16

Protein Synthesis

Answer 16

DNA is master blueprint that holds the code for protein synthesis

Question 17

Transcription

Answer 17

‘DNA information coded in mRNA

Question 18

Translation

Answer 18

mRNA decoded to assemble polypeptides

Question 19

Translation

Answer 19

mRNA decoded to assemble polypeptides

Question 20

Transcription factors

Answer 20

protein complex) activate transcription ‘

Loosening histones from DNA in area to be transcribed so DNA segment can be exposed
•Binding to special sequence of gene to be transcribed, called promoter (starting point)
‘
•Mediating binding of RNA polymerase, enzyme that synthesizes mRNA, to promoter region

Question 21

Initiation

Answer 21

RNA polymerase separates DNA strands

Question 22

Elongation

Answer 22

RNA polymerase adds complementary nucleotides to growing mRNA matching sequence of based on DNA template strand

Question 23

Termination

Answer 23

Transcription stops when RNA polymerase reaches special termination signal code

Question 24

-Anticodon

Answer 24

. at other end (head) is triplet code that determines which amino acid will be bound at stem

Question 25

Translation. Initiation

Answer 25

Small ribosomal subunit binds to a special initiator tRNA (methionine) and then to the mRNA to be decoded

Question 26

Translation
Elongation

Answer 26

►Codon recognition: tRNA binds complementary codon in A site of ribosome
►Peptide bond formation: Ribosomal enzymes transfer and attach growing polypeptide chain from tRNA in P site over to amino acid of tRNA in A site

Question 27

Translation
Termination

Answer 27

When one of three stop codons (UGA, UAA, UAG) on mRNA enters A site, translation ends’Final polypeptide product will be further processed by other cell structures into functional 3-D protein