Transcript cellular reproduction

CELLULAR
REPRODUCTION
BINARY FISSION & THE CELL
CYCLE (INTERPHASE – MITOSIS –
CYTOKINESIS)
Vocab you should know…
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Cellular reproduction: the way that cells
reproduce
Asexual reproduction: reproduction that
does not involve the union of gametes;
where one parent produces offspring that
are genetically identical to it
More vocab…
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Binary fission: division of a prokaryotic cell
into two offspring cells
Mitosis: period of nuclear cell division in
which two daughter cells are formed, each
containing a complete set of chromosomes
Interphase: cell growth phase where a cell
increases in size, carries on metabolism,
and duplicates chromosomes prior to
division
More vocab…
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Prophase: 1st & longest phase of mitosis
where chromatin coils into visible
chromosomes
Chromatin: long, tangles strands of DNA
found in the eukaryotic cell nucleus during
interphase
Chromosomes: cell structures that carry
the genetic material that is copied & passed
from generation to generation of cells
More vocab…
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Metaphase: short second phase of mitosis
where doubled chromosomes move to the
equator of the spindle & chromatids are
attached by centromeres to a separate
spindle fiber
Chromatids: one of the two strands of a
chromosome that become visible during
meiosis or mitosis
Centromeres: region of the chromosome
that holds the two sister chromatids
together during mitosis
More vocab…
Anaphase: phase of mitosis where
centromeres split and the chromatid
pairs of each chromosome are pulled
apart by microbtubules
 Microtubules: thin, hollow cylinders
made of protein that provide structural
support for eukaryotic cells
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More vocab…
Telophase: final phase of mitosis
during which nuclear membranes form
around each new set of chromosomes
 Haploid: cell with one of each kind of
chromosome (n)
 Diploid: cell with two of each kind of
chromosome (2n)
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More vocab…
Cytokinesis: cell process following
mitosis in which the cell’s cytoplasm
divides & separates into two new
daughter cells
 Cell plate: precursor of a new plant
cell wall that forms during cell division
& divides the cell into two
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CELLULAR
REPRODUCTION - BASICS
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Two basic types:
Binary fission
 Cell cycle
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Prokaryotic Reproduction
Binary
fission
It’s a form of asexual
reproduction
Most prokaryotic cells
reproduce this way
Binary Fission Owl 154
Eukaryotic Cell
Reproduction: The Cell
Cycle
Interphase: repeating set of events in the
life of a cell, made of 3 phases; time
between cell divisions, duplication of DNA
& cell parts
 Mitosis: reproduction & division of
nucleus
 Cytokinesis: division of cytoplasm &
formation of new cells
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Cell Cycle Simulation
INTERPHASE
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Interphase: Longest phase of cell division;
divided into 3 phases; starts after the last cell
division when daughter (offspring) cells are
about ½ the size of the parent cells
G1 phase: cell growth – offspring cells grow to
adult size
S phase: DNA is copied & cell parts are
duplicated
G2 phase: cell growth & preparation for division
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Kangaroo rat interphase
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Interphase
Interphase:
organelles double
in #, DNA replicates, protein
synthesis occurs,
chromosomes are not visible
b/c DNA appears as uncoiled
chromatin.
Interphase
MITOSIS
Mitosis:
Divided into 4
different phases
follows interphase
Is followed by cytokinesis
Mitosis
Mitosis: Prophase, step 1
 Nuclear
membrane & nucleolus
disappear; chromatin condenses
& chromosomes become visible
as chromatids; sister chromatids
pair up; spindle fibers are
assembled.
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Kangaroo rat prophase
Mitosis: Prophase
Mitosis: Metaphase, step 2
Sister
chromatid pairs line up
along the cell’s equator;
spindle fiber attach to the
centromeres holding them
together.
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Kangaroo rat metaphase
Mitosis: Metaphase
Mitosis: Anaphase, step 3
 Sister
chromatids split apart at the
centromere as the spindle fibers
shorten & “pull” them toward
opposite poles; cleavage furrow
appears.
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Kangaroo rat anaphase
Mitosis: Anaphase
Mitosis: Telophase, step 4
 Chromatids
reach opposite poles,
nuclear membrane & nucleoli
reform, cleavage furrow deepens;
spindle fibers disappear;
chromatids uncoil to chromatin.
Kangaroo rat telophase
Mitosis: Telophase
Cytokinesis; last
phase of cell cycle
Cytokinesis
follows mitosis;
dividing cell separates into
2 diploid daughter cells
Different in animal and
plant cells
Cytokinesis in animal cells
animal cells lack a cell wall and are
surrounded only by a plasma membrane
 Cleavage furrow deepens until the two
furrows meet & pinch apart the cytoplasm
creating two separate cells called daughter
cells
 Cytokinesis real time
 Kangaroo rat cytokinesis
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Cytokinesis in Animal Cells
Cytokinesis in plant cells
plant cells are surrounded by a cell wall in
addition to the plasma membrane
 A cell plate is formed along the equator of the
cell & separates the cytoplasm into two
daughter cells.
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Cytokinesis in plant cells
Cellular Reproduction Quiz
1.
2.
3.
What are the two basic types of
cellular reproduction?
Binary fission is a type of _________
reproduction.
What are the 3 phases of the cell
cycle in eukaryotic reproduction?
Quiz Cont’d
4.
5.
6.
7.
What happens to the DNA during
interphase?
What are the 4 phases of mitosis?
During what phase of mitosis do the
duplicated chromosomes line up at
the equator?
During which phase do the sister
chromatids move towards opposite
poles?
Quiz Cont’d
8.
9.
10.
During which phase does the
nuclear membrane reform?
How many cells are there at the end
of cytokinesis?
What is different in plant cell
cytokinesis than in animal cell
cytokinesis?