78 terms

Biology Chapter 5 Test

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synthesis
during which stage of the cell cycle is the DNA copied?
the ratio of cell surface area to volume; an increase in size could result in a surface area too small for the exchange of materials
what limits the maximum size of a cell?
they stimulate cell division
how does growth factor influence the cell cycle?
cancer cells don't contribute to functions of the body and can't be stopped by growth factors
how do cancer cells differ from healthy cells?
they are similar because they both methods of cell division where two daughter cells that are genetically identical to the parent cell; they are different because the processes differ as well as if they are prokaryotic or eukaryotic
how are mitosis and binary fission similar and different?
to maintain homeostasis, a cell has to be able to communicate between cells of different types; a brain cell has to send signals to the body to keep processes going
how do multi cellular organisms depend upon interaction among different cell types?
so that you can have complex systems and grow; if you didn't have cell differentiation you wouldn't have arms, legs, heart, organs, etc
why is cell differentiation important?
can divide and renew themselves
remain undifferentiated
develop into a variety of cells
what are the characteristics of stem cells?
cells, tissues, organs, organ systems
explain the order of cells to organ systems
G1, S, G2, and M
what are the four main stages of the cell cycle?
prophase, metaphase, anaphase, and telophase
four phases of mitosis
mitosis
process of dividing the nuclei into two genetically identical nuclei
cytokinesis
where the cell cytoplasm actually divides
prophase
where the duplicated chromosomes condense tightly
binary fission
process in which prokaryotes' reproduce; a cell divides into two equal parts
location
much of cell differentiation is determined by the _________ of the cell
by looking how degraded the telomere is, longer=younger shorter= older, new cells are smaller, nucleus takes up more space in cell=younger
how would you visually distinguish between newly formed cells and older cells?
Cell Cycle
a regular pattern of growth, DNA duplication, and cell division that occurs in eukaryotic cells
Mitosis
the division of the cell nucleus and its contents
Cytokinesis
the process that divides the cell cytoplasm
Chromosome
one long continuous thread of DNA that consists of numerous genes along with regulatory information
Histones
a protein that DNA wraps around at regular intervals in order to become more compact in size.
Chromatin
loose combination of DNA
Chromatid
the name for one half of a duplicated chromosome
Sister Chromatid
the name for two identical chromatids
Centromere
region where sister chromatids are held together.
Telomeres
the ends of DNA molecules which are made of repeating nucleotides that do not form genes.
Interphase
the resting phase between successive mitosis
Growth factors
broad group of proteins that stimulate cell division.
Apoptosis
programmed cell death; when internal signals activate genes that help produce self destructive enzymes
Cancer
common name for a class of disease characterized by uncontrolled cell growth.
Benign tumor
the cancer cells typically remain clustered together
Malignant tumor
the cancer cells break away from the tumor
Metastasize
breaking away and spreading of tumor cells throughout the body
Carcinogens
substances known to produce or promote the development of cancer; uv rays, tobacco, radiation
Asexual reproduction
production of offspring from a single parent and does not involve the joining of gametes.
Binary fission
type of asexual reproduction by which the cell divides into two cells of the same size; used by most prokaryotes
Tissues
groups of cells that work together to perform a similar function; muscle, skin, and fat
Organs
groups of tissues that work together to perform a specific function or related function; heart, lungs, and kidney
Organ system
organs that carry out similar functions; circulatory, nervous, and respiratory
Prophase
phase of mitosis when chromatin condenses into two sister chromatids, nuclear envelope breaks down, and spindle fibers grow from the centrioles.
Metaphase
phase of mitosis where spindle fibers attach to a protein structure on the centromere of each chromosome. Chromosomes align along the cell equator.
Anaphase
the phase of mitosis where sister chromatids separate and are moved to opposite sides of the cell.
four phases of mitosis
PMAT
Telophase
the phase of mitosis where two identical chromosomes is positioned at each pole of the cell. The nuclear membranes start to form, the chromosomes begin to uncoil, and the spindle fibers fall apart.
Gap 1 Stage
1st stage of the cell cycle where a cell carries out normal cell functions, cell grows, and organelles are duplicated.
Synthesis stage
2nd stage of the cell cycle where the cell makes a copy of its nuclear DNA.
Gap 2 stage
3rd stage of the cell cycle where the cell continues normal functions but there is additional growth. This stage includes a critical checkpoint for size and undamaged DNA.
cell differentiation
process by which unspecialized cells develop into their mature forms and functions
stem cells
unique type of body cells that have the ability to divide , remain undifferentiated, and develop into a variety of cell types
nonchanging
a ____________ environment is good for asexual organisms
changing
a ______________ environment is better for sexual organisms
totipotent
stem cell that can grow into any other cell type; fertilized egg
pluripotent
stem cell that can grow into any cell type except totipotent; embryo
multipotent
stem cells that can only row into cells of closely related family
external and internal
two types of factors that regulate cell division
physical and chemical
two types of external factors that regulate cell division
chemical factor
when there are signals sent to trigger a cell to stop dividing
physical factor
cells touching creates contact inhibition
contact inhibition
when a cell decides to stop growing because it touches another
erythropoetin
trigger an increase in red blood cell production
kinases and cyclins
two types of internal factors
kinases
enzyme that, when activated, takes a PO4 and adds it to its target
cyclins
proteins that are made and destroyed at certain points in the cell cycle that help a cell advance to different stages of the cell cycle
phagocytize
"gobble up"
necrosis
when a cell dies that has been injured
your body needs some cells more than others so the demand is higher; skin cells and intestine cells receive more wear and tear so they need to regenerate quicker
why do cells divide at different rates?
smaller
the surface area to the volume ratio of a cell gets __________ as a cell gets larger
prophase
what stage of mitosis is this cell in?
metaphase
what stage of mitosis is this cell in?
anaphase
what stage of mitosis is this cell in?
telophase
what stage of mitosis is this cell in?
telophase
what stage of mitosis is this cell in?
the child would not be able to produce new cells and tissues at the proper rate and the height and weight would be affected
how would a child being born with growth hormone receptors that do not work properly affect the child's development?
HeLa cells
cell lined used for scientific research from henrietta lacks
because in order for the cancer cells to divide and multiply the would need spindle fibers for mitosis, so if there was no spindle fibers the cancer cell would die
why would anticancer drugs that prevent microtubules from forming spindle fibers be effective for cancer treatment?
the destruction of human embryos
what is the ethical problem with stem cells?
each piece would become a new flat worm not kill it (fragmentation)
briefly explain why cutting a flat worm into pieces wouldn't kill it.