CHAPTER 20: MITOSIS & ASEXUAL REPRODUCTION

20-1: MITOSIS

Why do cells need to divide?

·       ________________ organisms à _____________

·       ________________ organisms à __________________

·       Cells become __________________________ themselves 

2 Forms of Reproduction:

Chromosome Structure

·       In Nondividing cells,

·       In Dividing cells (cells in mitosis),

The Cell Cycle – Period of time from the ________________ _______________________________. Cycle of growth & division in cells. There are 5 Phases:

1.  G1: “First Gap” –

2.  S: “Synthesis” –

3.  G2: “Second Gap” –

4.  M: “Mitosis” – Nuclear division.

5.  C: “Cytokinesis” –

STAGES OF CELL DIVISION (MITOSIS)

Interphase: Resting stage – _____________________!

·       __________________ in size

·       More ________________, _____________, & ___________ __________________ are produced

·       ______________________________, become doubled chromosomes with _______________________

·       _______ appears as a ____________________________ _________________________ (spagetti)

·       ______________________________ – they replicate also

Prophase: Doubled _______________ visible; they _________ ___________________________________.

·       Pairs of __________________________________________

·       _________________ extend from centrioles to form star-shaped structures called ______________

·       Spindle microtubules go from pole to pole

·       _________________________________________________

·       ________________ begin to _________________________

·       _______________________________________________

Metaphase: ________________________________________.

·       _____________________________

·       _________________ on chromosomes ________________, giving rise to ­­­­­­­­­­­­­­_____________________________________.

Anaphase:

Telophase: 2 new nuclei exist, each with a complete set of chromosomes

·       _______________________, get _____________ and take a ______________ appearance of ________________

·       ___________________________________

·       ____________________ around each new daughter nucleus

·       _________________________

Cytokinesis in Animal Cells

·       Cell _____________________, _____________________

·       ___________________________, each with a ___________ _______________________________

Cytokinesis in Plant Cells

·       ______________________

·       __________________________

·       ________________________________________ à grows outward and joins the old cell wall, ____________________.

TIME SPAN OF MITOTIC CELL DIVISION

Human cells in tissues culture spend approximately ________ in _____________, and ______________ in ______________, preparing for division.

More specialized cells divide less often:

à

à

CONTROL OF THE CELL CYCLE

Cyclin:

S-Cyclin –

M-Cyclin –

_________________________________. They ____________ _________________ in an uncontrolled fashion. This is a ________________________________________.

20-2:ASEXUAL REPRODUCTION

·       _____________________________________________ undergo asexual reproduction.

·       Each _____________ has the ________________________ _________________ (DNA) as the _________________.

·       Results in ___________________________________

TYPES OF ASEXUAL REPRODUCTION

Binary Fission –

Ex: ______________, _____________, many ____________

Fission in Bacteria:

·       Occurs every ________________ (appx)

·       Single ________________________ attaches to plasma membrane and ________________

·       ___________________________________ and its copy

·       Cell _____________________________________________, each containing 1 chromosome (sometimes the cells do not separate, forming a chain of bacteria)

·       Each __________________________________________

Fission in Amoeba (Protozoan)

Divides by ___________________

Fission in Paramecium

·       Paramecium has 2 nuclei: a _________________________ ________________________

·       _______________ divides by _____________, ___________ divides by a _____________________________

·       _________________________________________________

·       ___________________________, 2 new _______________ ______________________________

·       Middle of cell pinches in à __________________

·       Paramecium may __________________________

Budding –

·       _______________________________________________ on outer surface of parent organism

·       ____________________________ and live independently ____________________________, forming a colony

·       __________ and __________ are ____ the ______________

·       Ex: ___________, ___________, sponges & worms

Budding in Hydra:

·       _____________________________ on the side of the parent undergo ___________, producing a ____________________

·       These _______________________, and in a few days a small ________________ with mouth and tentacles is _____

·       _________________________________

·       Hydra may ___________________________

Budding in Yeast:

·       _______________________ to a certain size

·       _______________________________________ of the cell

·       _________________________________ near the nucleus so that it _______________________________________

·       _________________________________

·       __________________ moves into the _______, __________ _____________ remains in the ______________

·       ____________________ between _____________________

·       ______ may _____________ or _______________________

·       ____________________________, can increase in size and ____________________

·       Yeast may _____________________________

Spore Formation

·       Spore:

·       Spores have most _______________. They may also have a __________________________ or _____________.

·       Formed ______________ or _______________

·       Ex: ___________, ________ & _____________ form spores

Spore formation on Bread Mold (Fungus)

·       Spores _____________________ in _______________ on specialized __________ that grow upward from the surface

·       _________________________________ when spores are fully grown à ___________________________________

·       ________________________________________________ ________________ to form a ________________________.

Regeneration –

(hydra, planarian, starfish, earthworm).

The power of ____________________________________ as ______________ become more __________________.

Vegetative Reproduction –

·       ___________________________ (cambium & epidermal cells) _______________________ and ________________ to become an ____________________________.

·       The _____________ has the _____________ as the parent

Natural Vegetative Reproduction

Artificial Vegetative Reproduction

Advantages to Artificial Vegetative Reproduction

·       Produces ________________________________ to maintain _____________________

·       ___________________________ than seeds

·       ____________________________

·       _______________________

·       _______________________ of fruits or nuts