Nucleus

Question 1

Where do you see Barr bodies in samples?

Answer 1

small attachment to the nuclear envelope of epithelial cells or a drumstick appendage to PMN’s

Question 2

What does the nucleolus do?

Answer 2

ribosomal RNA synthesis and ribosomal assembly

Question 3

What are the 3 regions of the nucleolus and what do they do?

Answer 3

Fibrillar centers: loops of chromosomes contain DNA (look like holes)
Fibrillar material: genes being actively transcribed (dark areas)
Granular material: densely packed preribosomal particles (grainy)

Question 4

What is the nuclear envelope?

Answer 4

2 membranes with a perinuclearcisternal space between them

Question 5

What is the nuclear lamina?

Answer 5

network of protein filaments that serves as scaffolding/support

Question 6

the nucleoplasm includes everything in the nucleus except what?

Answer 6

the chromatin and the nucleolus

Question 7

What are the 2 checkpoints for G1?

Answer 7

Restriction point CP: mediated by retinoblastoma susceptibility protein
G1 DNA damage CP:mediated by tumor suppressing protein p53

Question 8

What is the checkpoint for S phase?

Answer 8

S DNA damage CP

Question 9

What are the checkpoints for G2?

Answer 9

G2 DNA damage CP

Unreplicated DNA damage CP

Question 10

What are the checkpoints for M phase?

Answer 10

Spindle assembly checkpoint

chromosome segregation CP

Question 11

What proteins power cells through the checkpoints?

Answer 11

Cyclin and clycin-dependent kinase

Question 12

What are the sequential phases of Phophase I in Meiosis I?

Answer 12

Leptotene, Zygotene, Pachytene, Diplotene, Diakinesis

Question 13

What is the difference between necrosis and apoptosis?

Answer 13

Necrosis is pathological and apoptosis is physiolgical