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
Sexual reproduction: reproduction where
gametes from two parents unite to form
offspring
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:
Asexual
 Sexual
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Prokaryotic Reproduction
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Binary fission
It’s a form of asexual reproduction
 Most prokaryotic cells reproduce this
way
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Binary Fission
Eukaryotic Cell Reproduction:
The Cell Cycle
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Cell cycle: repeating set of events in the life
of a cell, made of 3 phases
Interphase: time between cell divisions,
duplication of DNA & cell parts
Mitosis: reproduction & division of nucleus
Cytokinesis: division of cytoplasm &
formation of new cells
Cell Cycle Simulation
INTERPHASE
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Longest phase of cell division; divided into 3
phases; After cell division: 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
G2 phase: cell growth & preparation for
division
Kangaroo rat interphase
Interphase
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Interphase: organelles double in #, DNA
replicates, protein synthesis occurs,
chromosomes are not visible b/c DNA appears
as uncoiled chromatin.
MITOSIS
Divided into 4 different phases
 Follows interphase
 Is followed by cytokinesis
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Mitosis: Prophase, step 1
Nuclear membrane & nucleolus
disappear; chromatin condenses &
chromosomes become visible as
chromatids; sister chromatids pair up;
spindle fibers are assembled.
 Kangaroo rat prophase
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Mitosis: Metaphase, step 2
Sister chromatid pairs line up along
the cell's equator; spindle fiber attach
to the centromeres holding them
together.
 Kangaroo rat metaphase
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Mitosis: Anaphase, step 3
Sister chromatids split apart at the
centromere as the spindle fibers
shorten and “pull” them toward
opposite poles;
cleavage furrow
appears.
 Kangaroo rat anaphase
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Mitosis: Telophase, step 4
nuclear membrane & nucleoli reform,
cleavage furrow deepens; spindle
fibers disappear;
chromatids uncoil to
chromatin.
Kangaroo rat telophase
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Cytokinesis; last phase of
cell cycle
Follows mitosis;
 dividing cell separates into 2 diploid
daughter cells
 Different in animal and plant cells
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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
 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
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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.
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6.
7.
What happens to the DNA during
interphase?
What are the 4 phases of mitosis?
During what phases of mitosis do the
duplicated chromosomes line up at
the equator?
During which phases do the sister
chromatids move towards opposite
poles?
Quiz Cont’d
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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?