Chapter
12
Quizzes:
Self
Activities
Chapter
Cum.
Videos
Movies
Words
Appendix
Summary
Art
Art
Unit 2: The Cell
The Cell Cycle
Review
The continuity of life is based upon
cell
, the
reproduction
of cells. Cell
division
takes place in a sequence of events called the cell
.
Cell
division
is asexual and results in
identical
cells; each of which receives an exact copy of the genetic material,
, from its "parent".
Prokaryotes reproduce by a type of cell division called
fission,
where the DNA is
, and then the two daughter DNA strands actively move apart.
Eukaryotic DNA is packaged
into
, a complex of
and
that
condenses
into
during cell
division.
cells have
sets of chromosomes and reproduce asexually by
, while
(sex cells) have
set of
chromosomes
and reproduce by
.
The cell
cycle
consists of an
and a
phase.
Interphase can be divided into
subphases
,
, and
.
The mitotic phase consists of
, the division of the nucleus, and
, the division of the cytoplasm.
Mitosis
consists of 5
phases,
or stages: 1)
, 2)
, 3)
, 4)
, 5)
.
In
, chromatin condense into visible
, and the
mitotic
arises
from
the
and is made of
.
In
, the nuclear envelope breaks down, and
microtubules attach to the
of chromosomes.
In
, the
microtubules move the chromosomes to the
, or equatorial, plate.
In
, sister
separate, and move along the
kinetochore
toward opposite ends of the cell.
In
, genetically identical daughter
form at opposite ends of the cell.
Cytokinesis:
In animal cells, a
furrow
forms, and a
ring of
splits the
cell.
In
plant
cells,
a cell
, fused from
, grows at the
equator,
then new cell
form between the daughter cells.
Review:
Mitosis and Cytokinesis Animation
Chapter
13
Quizzes:
Self
Activities
Chapter
Cum.
Videos
Movies
Words
Appendix
Summary
Art
Art
Unit 3: Genetics
Meiosis and Sexual Life Cycles
Review
All living organisms can
reproduce,
and transmit
from one generation to the next, with variation.
The units of heredity are
segments
of
called
. Each gene is found at a region on a
called its
. An organism's total
genes
is its
.
In
reproduction, one parent produces
genetically
offspring
by
or
fission.
In
reproduction, two parents produce offspring that have unique combinations of
inherited from each
parent.
A
is an ordered, visual
representation
of the
in a cell.
In humans, each
cell has
chromosomes made up of two sets, with one set coming from each parent.
44 of these are pairs of
chromosomes, or
, and have the same
; each of the pair comes from each of the parents of the individual.
The other two chromosomes are
chromosomes, called X and Y, which determine the
gender
of the individual. Cells having a full
complement
of chromosomes are
.
Each
chromosome
consists of two identical sister
, attached to the
.
are the sex
cells
involved in
reproduction, and are
, containing only one set of chromosomes.
Gametes are produced from
cells in organs called
by
meiosis.
occurs when a sperm fuses with an ovum, forming a diploid
, which grows and develops into an adult
organism.
Since
meiosis
reduces the number of chromosome sets from
to
, two cellular divisions are required.
Meiosis
is the chromosome
division, and
meiosis
produces
haploid daughter cells.
Prophase
I
Metaphase
I
Anaphase
I
Telephase
I
Meiosis
II
Sexual reproduction produces genetic
by several mechanisms:
independent
,
crossing
, and
random
fertilization.
The tremendous genetic variation made possible by
meiosis
and
reproduction provides raw material for evolution by
selection.
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