Transcript Growth and Development

Do Now: discuss the difference
between cellular growth and
development.
• Homework: finish 10-2
The American Robin is about 10
inches long (25 cm), and has a
brick-red breast, with gray
wings, head and back.
The female typically lays
two clutches of eggs
each year. Each clutch
typically has 3 or 4 eggs.
After the eggs hatch, the
young stay for about 2
weeks then leave.
Babies are born hairless with
their eyes closed. One mother
mouse can produce over 100
babies a year.
As adults, their long thin
bodies are from 2.8 to
13 centimetres long.
They eat plants such as
grains, fruits and seeds.
The polar bear or the
sea/ice bear are the
world's largest land
predators. Male polar
bears may grow 10 feet
tall and weigh over 1400
pounds. Females reach
seven feet and weigh 650
pounds.
The babies are much smaller
than human babies when
they're born. They are the size
of a rat and weigh little more
than a pound.
Baby Pictures - Northern Resident Killer Whale
This little transient killer whale was just a few days old
when I took these baby pictures. When orca whales
are born their white patches are actually orange.
As this baby pictures showing, a killer whale can
swim within 30 minutes of its birth and by a few days
old is partly able to keep up with the rest of the pod.
This baby is just the
5th elephant born as
a result of artificial
insemination. The
little guy weighed
325 pounds at birth.
He may weigh as
much as 13,000
pounds someday.
The whale shark is the world's largest
living fish. Its massive, body reaches
lengths in excess of 46' (14m). The
whale shark is a live-bearer. Pregnant
females were recently found to contain
hundreds of young, up to about 2'
(60cm) long.
How organisms grow, heal and
reproduce
Growth and Development
• Each of these animals began as a single
fertilized cell.
• Cell division or Mitosis allows organisms to
grow
– an organism’s cells do not actually get larger,
they make more cells!
– http://nobelprize.org/educational_games/medicine/2001/cellcycle.html
• Development occurs when the cells
change shape to become new structures
Growth—Like in Radish Seedlings
Healing and Replacement
• Mitosis allows
new cells to
replace the old
ones.
• Mitosis will occur
even quicker if
cells are lost
because of a
wound.
Regeneration—Replacing limbs
Reproduction
• Unicellular organisms rely on cell division for
Asexual Reproduction
Characteristics of Mitosis
• New cells produced by mitosis or cell
division are “CLONES.”
– They have identical DNA
– They originated from a single parent
– The new cells are called daughter cells
Cells Divide!!
Limitations to Cell Growth
1. Larger a cell becomes, the more demand
on DNA. Why?
-The larger a cell becomes, the harder it is for a
cell’s DNA to keep up with the entire cell.
-Compare it to a growing town…
-…….Library has enough books for a small town,
when it continues to grow the library can no longer
keep up with the demands of the citizens.
Limitations to Cell Growth
2. Exchanging of materials.
- water, food, oxygen come in the cell.
- wastes leave the cell.
- not always at the same rate because
water, food, oxygen aren’t always used at
the same rate.
Division of the Cell
-Cell Division- the process by which a cell
divides into 2 daughter cells.
-Parent Cell- original cell
-Daughter Cells- 2 cells produced after the parent
cell divides.
-Before a cell divides DNA copies or replicates
itself. 1 set of DNA for each daughter cell.
-Cell division solves the problem of a cell getting
too large
Cell Division
2 stages of Cell Division:
- Mitosis- Division of the cell nucleus
- Cytokinesis- Division of the cell cytoplasm
Before cell division can occur, chromosomes
need to replicate!
- chromosomes aren’t visible in cell until cell
division.
- at beginning of cell division the
chromosomes become visible contract into
dense, visible structures.
What is the cell cycle?
Series of events that cells go
through as they grow and
develop.
What are the stages of OUR
life cycles?
Link: Cells Alive Cell Cycle