Download Reproduction Chapter 5

Reproduction
Chapter 5
B. Gillis
Science 300
Famous Cell Biologists
(5.1)
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Robert Hooke (1665) –first used the term “cell”
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Anton van Leeuwenhoek (1680) – first to
observe tiny living organisms; known as the
father of microbiology
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Robert Brown (1820) - discovered the nucleus
in a cell
The Cell Theory
(5.1)
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1) All living things are composed of one or
more cells
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2) The cell is the fuctional unit of life
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3) All cells come from pre-existing cells
Types of Microscopes
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(5.1)
1) Compound Light Microscope- uses light and
two lenses, less than 2000X magnification,
able to see entire cell and living organisms
2) Transmission Electron Microscope- uses
beams of electrons, up to 2,000,000X
magnification, able to view organelles
3) Scanning Electron Microscope- up to
400,000X magnification, 3D images
Two Types of Cells (5.2)

Prokaryotic cells have no organized nucleus.
These are found in simple organisms like
bacteria. Unicellular-one cell organisms
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Eukaryotic cells have an organized nucleus
and organelles. They can be found in complex
organisms like humans.
Multicellular-many cell organisms
Animal and Plant Cell
(5.2)
View the following animal and plant cell and pay
attention to 1) what organelles are in both and
2) which can only be found in one
http://www.cellsalive.com/cells/cell_model.htm
Gillis Lecture Notes
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Cell division within the human body ( cells
actively dividing)
Cell division in both Plants and Animals;
primitive forms of life and complex forms
Different division rates (rapidly vs. no division)
Mitosis vs. Meiosis
3 Functions of Cell Division (5.4)
( Why do cells divide?)
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1) To Repair and Heal Tissue -Replacement of
damaged cells and birth of new cells
2) To Grow -Increase the number of cells
(adulthood), growth relies on division not size
3) To Reproduce the Organism- continue the
species,
The Cell Cycle
(5.5)
The cell cycle represents the entire life of a cell.
Mitosis
(5.5)
Mitosis Video
http://www.cellsalive.com/mitosis.htm
http://www.johnkyrk.com/mitosis.html
Difference between
Asexual Reproduction and
Sexual Reproduction

Asexual Reproduction- creating offspring that
are genetically identical to the parent

Sexual Reproduction- offspring the result of
two sex cells uniting to form a zygote
–
Zygote- fertilized egg
Asexual Reproduction
Types of Asexual Reproduction

Binary Fission- an organism splits into two
equally sized offspring each having a copy of
the parent’s genetic material
Bacteria
Types of Asexual Reproduction

Budding- offspring begin as an outgrowth of
the parent, then break off on their own
Hydra
Types of Asexual Reproduction

Fragmentation- a new offspring is formed from
a piece that broke apart from the parent.
Starfish
Types of Asexual Reproduction

Spore Formation- small, identical cells (spores)
are created within the parent. Each spore has
the capability to develop into a mature
organism.
Spores
Types of Asexual Reproduction

Vegetative Reproduction- organisms produce
runners which have the ability to develop
another organism.
Strawberry plants
Answers to Section 5.8 pg. 161
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1. Asexual Reproduction- one parent, one cell divides
into two identical cells
Sexual Reproduction- two parents, two cells fuse to
form a unique cell
2. Each new cell requires a copy of the original
information. Each cell has the complete genetic info to
be any of the specialized cells of the body.
3. The zygote has a combination of genes from both
parents, while the cell that undergoes mitosis is
identical to its parent.
5.8 Answers continued
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4. Binary Fission- organism splits into two equal-size offspring
Budding- the offspring begin as an outgrowth of the parent.
Spore Formation- the organism undergoes cell division to produce
a duplicate cell. The spore is usually housed within the parent
cell.
Fragmentation- a part of the organism breaks off from the parent
and forms a new organism
Vegetative Reproduction- a section of a plant is used to grow a
new plant. The section does not need to be removed from the
original plant.
5. a) fragmentation b) vegetative reproduction c) budding
Hormones

Hormones- chemical
messengers
produced in one part
of the body and can
affect cells in other
parts of the body
Hormones
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A hormone is released by one of about a
dozen glands, travels through the blood until it
reaches a cell with a receptor that it fits. Then,
like a key in a lock, the hormone molecule
attaches to the receptor and sends a signal to
the cell. The signal may tell the cell to increase
or decrease cell division and reproduction.
Do questions 1-5 on page 165
Answers to Section 5.10 pg. 165
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1. Hormones are chemical regulators produced in one
part of the body that affect cells in other parts of the
body.
2. The release of plant hormones can be stimulated by
light or temperature. The release of human hormones
can be stimulated by cell damage, stress, and blood
sugar.
3. Auxins are plant hormones that cause plant cells to
elongate. Cytokinins are plant hormones that stimulate
cell division.
5.10 Answers continued
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4. Growth hormone triggers cell division and
increases the production of new proteins. Low
production in childhood can result in dwarfism.
High production can result in giantism.
5. Calluses form only in areas where cell
damage has occurred the damage cells
release chemical messengers, causing cells in
the same area to begin dividing.