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