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! – 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

Questions: How is cell division different between bacteria and the radish root tip? Name three reasons why cells would divide? When would mitosis be fastest in a multicellular organism? Which cells in the human body would probably undergo cell division the most frequently? Why?