The Nucleus and DNA Replication

Question 1

Nucleus

Answer 1

• largest and most prominent cell organelle
• control center of the cell, stores genetic instructions for making proteins
• in nucleus is the blueprint for eveyrhting a cell will do and products it will make

Question 2

what is nuclear envelope

Answer 2

membrane around nucleus
- covers 2 bilayers with some fluid in between

Question 3

nuclear pore

Answer 3

tiny passageway for passage of proteins, RNA and solutes between brain

Question 4

Nucleolus

Answer 4

region of nucleus that is responsible for manufactorign the RN necessary for construction of ribosomes

Question 5

chromatin

Answer 5

• composed of DNA and associated proteins

Question 6

nucleosome

Answer 6

single wrapped DNA histone copmlex
- like a beaded necklace

Question 7

chromosome

Answer 7

dna and proteins in condensed form a chromatin
- humans have 46 chromosomes

Question 8

what is dna replication?

Answer 8

copying of dna that occurs before cell division can take place

• dna is made of 2 complimentary strands that fit and bind to each other to make double helix
• the two strands are antiparallel
• composed of alternating sugar and phosphate gropus
• adenine – thyamine cytosine – guanine
• mode of replication is semiconservative

Question 9

what are the steps of dna replication?

Answer 9

1. initiation: two strands are seperated (like zipper) using helicase
2. elongation: each strands becomes a template along which a new complementary strand is built
   - uses dna polymerase to bring correct bases to complement template strand
3. termination: once the two original strands are bound to their own and finished, dna replication stops and two near identical dna molecules are done