Chapter 5 : Cell Growth and Division KEY CONCEPT - Section 5.1 Cells have distinct phases of growth, reproduction, and normal functions. The ___________ is a regular pattern of growth, DNA replication, and cell division.

The main stages of the cell cycle are : ______ (G1): cell growth and normal functions ____________ (S): copies DNA ________ (G2): additional growth _________ (M): division of the cell nucleus (mitosis) _____________: division of the cell cytoplasm Mitosis occurs only if the cell is large enough and the DNA undamaged.

The rate of ______________ varies with the need for those types of cells.

Cell volume increases faster than cell surface area limits the _______ of cells materials have to be able to reach all parts of cell efficiently

KEY CONCEPT - Section 5.2 Cells divide during mitosis and cytokinesis. Chromosomes are formed at the start of mitosis. DNA becomes _______________- easier to organize DNA double helix DNA and histones Chromatin Supercoiled DNA

DNA plus proteins is called _____________ One half of a duplicated chromosome is a chromatid. Sister chromatids are held together at the centromere. ____________ protect DNA and do not include genes. chromatid centromere telomere Condensed, duplicated chromosome

cells spend _____ of the cell cycle in interphase cell grows, prepares to divide _____is duplicated Parent cell centrioles spindle fibers centrosome nucleus with DNA

Mitosis divides the cell’s nucleus in four steps: ____________ : chromosomes condense and spindle fibers form.

___________ : chromosomes line up in the middle of the cell.

___________ : sister chromatids separate to opposite sides of the cell.

__________: the new nuclei form and chromosomes begin to uncoil.

____________- splitting of cytoplasm and organelles between two new cells In _______cells, the membrane pinches closed between two cells In ______ cells, a cell plate forms new cell walls between the two new cells

Internal and external factors regulate _______________ KEY CONCEPT - Section 5.3 Cell cycle regulation is necessary for healthy growth. Internal and external factors regulate _______________ External factors include physical and chemical ________ Growth factors are proteins that stimulate cell division. Most mammal cells form a single layer in a culture dish and stop dividing once they touch other cells.

External factors trigger internal factors, which affect the cell cycle. Two of the most important internal factors are ________ and ___________ Cell growth is balanced by cell death in healthy organisms _____________ = programmed cell death. a normal feature of healthy organisms caused by a cell’s production of self-destructive enzymes occurs in development of infants

Cell division is uncontrolled in cancer - “immortal cells” _________cells form disorganized clumps called tumors. Benign tumors remain clustered and can be removed. _______________ metastasize, or break away, and can form more tumors. Cancer cells do not carry out necessary functions. Cancer cells come from normal cells with damage to ____________ involved in cell-cycle regulation. Carcinogens are substances known to promote cancer. - examples : ____________, tobacco, asbestos, exposure to environmental poisons Standard cancer treatments typically kill both cancerous and healthy cells.

________________ must allow for adequate exchange of materials. Cell growth is coordinated with ___________ Cells that must be large have unique shapes so that materials can still be exchanged with the environment efficiently

KEY CONCEPT - Section 5.4 Many organisms reproduce by cell division. ________________ is similar in function to mitosis. Asexual reproduction is the creation of offspring from a single parent. Binary fission produces _____daughter cells genetically identical to the parent cell. method of reproduction in ______________ parent cell DNA duplicates cell begins to divide daughter cells

Some eukaryotes reproduce through mitosis. Environment determines what form of reproduction is most advantageous. __________ reproduction is an advantage in consistently favorable conditions. __________ reproduction is an advantage in changing conditions. Some eukaryotes reproduce through mitosis. __________ forms a new organism from a small projection growing on the surface of the parent. ______________: splitting of the parent into pieces that each grow into a new organism. _____________________ forms a new plant from the modification of a stem or underground structure on the parent plant - type of asexual reproduction

KEY CONCEPT - Section 5.5 Cells work together to carry out complex functions. Multicellular organisms depend on interactions among different cell types. _______________ are groups of cells that perform a similar function. ___________ are groups of tissues that perform a specific or related function. ___________________ are groups of organs that carry out similar functions.

Specialized cells perform specific functions. Cells develop into their mature forms through the process of ____________________ Cells differ because different combinations of genes are expressed. A cell’s location in an embryo helps determine how it will differentiate. Outer: skin cells Middle: bone cells Inner: intestines

___________ are unique body cells. Stem cells have the ability to divide and renew themselves remain undifferentiated in form - they can “turn into” other types of cells develop into a variety of specialized cell types

Stem cells are classified into _______________. totipotent, or growing into ______ other cell type pluripotent, or growing into __________ but a totipotent cell multipotent, or growing into cells of a closely related cell family

Stem cells come from adults and ____________ Adult stem cells can be hard to isolate and grow. The use of adult stem cells may prevent transplant rejection. The use of embryonic stem cells raises ________ issues Embryonic stem cells are pluripotent and can be grown indefinitely in culture. First, an egg is fertilized by a sperm cell in a petri dish. The egg divides, forming an inner cell mass. These cells are then removed and grown with nutrients. Scientists try to control how the cells specialize by adding or removing certain molecules.

The use of stem cells offers many currently realized and potential benefits. used to treat leukemia and _______________ may cure disease or replace damaged organs. may revolutionize the ________________________