Cell Bio Exam 3 Week 10

What are HeLa cells?

-immortal because they are from a tumor

-used to study mitosis

-taken unknowingly from Henrietta Lacks

Cell States

-alive, but not dividing

-Alive, dividing

Description of a cell that is alive, but not dividing

-terminally differentiated (changing shape but not making new cells)

-cells waiting for a signal

-ex. muscles, many neurons, resting spores

Description of a cell that is alive and dividing

-progresses through the cell cycle

-cells duplicate at regular intervals

-progressing through an extra division to create a new organism

-ex. root tips, stem cells, repair cells

G0

-terminal differentiation

-alive but not dividing

-become a specific type of cell and cannot go back to become another type

-leaves G1 in response to signals

• dormant or differentiated into typical activities

What is cell division good for?

-differentiation/maturation

-growth (multicellular)

-replacement

-reproduction

Why is differentiation/maturation important in cell division?

-range of genes expressed becomes more narrow

-cells do more specific jobs

Why is growth (multicellular) important in cell division?

-increase size of organism

-increase amount of particular tissue

-as we get bigger, we need more cells

Why is replacement important in cell division?

-replacing cells lost due to cell death

Why is reproduction important in cell division?

-production of new organism

-asexual or sexual or both

What are the two major time periods of a cell’s life?

-interphase

-M phase

Basic description of interphase

-cells undergo a wide variety of normal cell activities

-overall cell organization is usually stable

-broken up into several stages (G1-S-G2)

Basic description of M phase

-cell structures/chromosomes are completely reorganized

-actually doing the division

-left with 2 new daughter cells

What happens if G1 is really short?

little to no growth

Which type of cell has the shortest G1?

gut epithelial cells