Exam 2 Ch. 8 Flashcards
How is asexual production involved in growth
Allows a cell to duplicate quickly and effectively. Cells duplicate themselves and split in half.
How is asexual production involved in healing
If you cut yourself, new cells form by asexual cell division to heal the cut
What is chromatin
DNA and associated histone proteins that have the appearance of thin threads.
DNA in its resting phase
What are chromosomes
Tightly packaged chromatin
When is the term sister chromatid used?
When duplicated chromosomes are attached by a centromere (sister chromatids have identical DNA)
What is Interphase and why is it the longest cycle
A period in which the cell is not actively dividing and is carrying out its normal functions. A cell is in Interphase all the the time it is not dividing.
What happens during G1
A cell doubles its organelles
Accumulates materials for DNA synthesis
Makes a decision whether to divide or not
What happens during S phase?
DNA is replicated
What happens in G2 Phase?
Growth phase
Protein synthesized as needed for cell division
Prepare to divide
What does Mitosis mean
period of nuclear division
Major events in Prophase
Chromosomes are condensing
Spindle begins to assemble
Nuclear envelope dissolves
Major events in Metaphase
Chromosomes line up at the metaphase plate
Major events in Anaphase
Sister chromatids separate as their pulled to opposite poles
Major events in Telophase
Spindle disappears
New nuclear envelope forms
Daughter cells are identical to parent cells
What does cytokinesis mean
Division of non-nuclear contents
How is cytokinesis different from plant to animal cells
Animal cells furrow whereas plant cells wall prevents a cleavage furrow. A plant cell plate forms to separate cells
What are the cell cycle checkpoints?
G1
G2
M
What is checked at the G1 checkpoint
DNA integrity checked. If repair is not possible cell undergoes apoptosis
What is checked at G2 checkpoint
Verifies DNA replicated
DNA damage repaired
What is checked at the M checkpoint
All chromosomes must be attached to spindle to pass
Example of a signal that would promote movement through the cell
Epidermal Growth Factor (EGF) stimulates skin near an injury to finish cell cycle and repair injury
Example of a signal that would slow/stop cell cycle
Contact inhibition- cells stop dividing when they touch
What is apoptosis
programmed cell death
unleashed by internal or external signals
How is the cell cycle changed in cancer cells
Cellular reproduction occurs repeatedly without end
Cells dont respond to inhibitory signals
Cells dont undergo apoptosis
What is an ongogene
Mutated proto-onco gene that has become cancer causing
What is a proto-onco gene
Code for proteins that promote the cell cycle and inhibit apoptosis
(Accelerate cell cycle)
What are tumor suppressor genes
codes for proteins that inhibit the cell cycle and promote apoptosis
