bio chapt 11: cell growth and division
steps used to repair damaged heart tissue
1. stem cells are filtered from bone marrow removed from a patient's hip 2. the stem cells are injected into the heart's damaged area 3. the environment of the heart stimulates injected stem cells to differentiate into new heart muscle cells
how long do embryonic cells take to go through the cell cycle
30 minutes
what needs to be duplicated before a cell can go through cell division?
DNA
phases of cell division
Interphase-G1, S phase, G2; M phase- mitosis and cytokinesis (also known as cell division)
explain the cause of limited cell size
The cause of limited cell size is decreased flow of nutrients/wastes and limited DNA in the cell needed to provide information for cell functioning, and the effect is cell division
wha happens to the surface-area-to-volume ratio as the cell increases in size? Will the cell continue to function efficiently as the cell size gets larger and larger?
The ratio decrease. The cell will function less efficiently
cancer
a disorder in which cells do not respond to regulatory factors, resulting in uncontrolled growth and division
tumor
a mass of cancerous cells that can benign or malignant
benign tumor
a noncancerous cell that doesn't spread to the rest of the body
describe an organism that uses both asexual and sexual reproduction
a strawberry plant forms a runner, which is a form of asexual reproduction, and it forms seeds from the flowers, which is a form of sexual reproduction
Differentiation in mammals
adult mammal cells reach a point where they can no longer differentiate
about how long does one cell cycle last in fertilized clam eggs?
around 27 minutes
what kind of fission do prokaryotes go through
binary fission
stem cells
cells that are unspecialized and can be found in an embryo
anaphase
chromosomes separate, and the sister chromatids move along spindle fibers to opposite sides of the cell
how does the concept of a circle relate to cyclins?
cyclins regulate the cell cycle, which occurs in a circular pattern
issues regarding the stem cells research
destruction of human embryonic life to harvest embryonic stem cells
defining differentiation
how cells become specialized to carry out specific functions
how do chromosomes differ in prokaryotes and eukaryotes?
in prokaryotes, a single circular chromosome holds most of the DNA, but eukaryotes have multiple coiled chromosomes
the steps of mitosis
interphase goes into prophase, then metaphase, then anaphase, then telophase
malignant tumor
invade and destroy surrounding healthy tissue
sexual reproduction
joining of two reproductive cells from each of two parents, offspring have some genetic material from each parent cell, more time needed for sexual reproduction, genetically diverse offspring
which type of tumor, benign or malignant, causes more damage to the body?
malignant
what occurs when MPF cyclin levels are highest?
mitosis
asexual and sexual reproduction
produce offspring, pass on genetic information to new cells
what are the four steps that occur during the M phase?
prophase, metaphase, anaphase, and telophase
benefits regarding the stem cells research
providing treatments for damaged cells, tissues, and organs
regenerative medicine
scientists are researching organisms that can regrow limbs in an effort to use the same steps in human medicine
induced pluripotent stem cells
scientists can modify existing skin cells to become pluripotent
asexual reproduction
simple, efficient, effective in increasing population quickly, genetically identical cells produced from single parent, lacking genetic diversity
metaphase
spindle fibers guide the centromeres of the duplicated chromosomes to line up across the center of the cell
human stem cell development
the first stage is a zygote; this develops into a blastocyst, which has two cell layers. The inner cell layer is pluripotent, which can become any cell type in the body
prophase
the nuclear envelope begins to break down, chromatids become visible and attach at the centromeres, spindle fibers form at the centrioles, and the centrioles begin to move to opposite poles of the cell
what occurs during telophase that signifies the end of mitosis?
the nuclear membrane reforms around the divided chromosomes
cell division
the process by which a cell divides into two new daughter cells
cell differentiation
the process by which cells become specialized
telophase
visible chromosomes begin to spread out into a cluster of chromatin, and the nuclear envelope forms around each mass of chromatin
ethical issues
when scientists harvest stem cells, the embryo is destroyed
