nucleus

Question 1

usually what shape

Answer 1

spherically

Question 2

how big

Answer 2

between 10 and 20 um

Question 3

what parts are there in the nucleus

Answer 3

• nuclear envelope
• nucleur pores
• nucleoplasm
• chromosomes
• nucleolus

Question 4

nuclear envelope

Answer 4

double membrane that surrounds the nucleus. its outer membrane is continuous with the endoplasmic reticulum of the cell and often has ribosomes on its surface. It controls the entry and exit of materials in and out of the nucleus and contains the reactions taking place within it

Question 5

Nuclear pores

Answer 5

Allows the passage of large molecules, such as messenger RNA, out of the nucleus. There are typically 3000 pores in each nucleus, each around 40 - 1000 NM in diameter.

Question 6

Nucleoplasm

Answer 6

Granular, jelly-like material that makes up the bulk of the nucleus.

Question 7

Chromosomes

Answer 7

Consist of protein-bound, linear DNA.

Question 8

Nucleolus

Answer 8

Small spherical region within the nucleoplasm. It manufactures ribosomal RNA and assembles the ribosomes. Could be more than one.

Question 9

Functions

Answer 9

• Act as the control center of the cell, through the production of mRNA and tRNA and hence protein synthesis.
• Retain the genetic material of the cell in the form of DNA and chromosomes
• Manufacture ribosomal RNA and ribosomes.