The Cell Cycle Flashcards
what are the main stages of the cell cycle?
interphase and mitotic phase
what are the stages within interphase?
G1 phase, S phase, and G2 phase
what are the stages within the mitotic phase?
prophase, metaphase, anaphase, telophase
interphase
- resting between cell division (which is a non-mitotic phase)
- very active
- gearing up for mitotic phase
G1 phase
- normal cellular activities
- normal cell growth
- normal duplication of organelles
- protein synthesis
S phase
- DNA replication occurs
- most vulnerable phase (which can cause DNA damage since replication of DNA occurs during this stage)
G2 phase
-synthesis of protein and microtubules (in the centriole)
mitotic phase
- nuclear division
- cytokinesis: cytoplasmic division
what are some possible fates of mitotic products (daughter cells)?
- differentiate (specialize) –> age –> die
- rest as an “uncommitted” cell
- enter a new cell cycle immediately (which has a rapid mitotic rate)
what two things vary with cell type?
- the capacity to grow and divide
- the rate at which these processes occur
what are the three main cell categories?
- cells that are extremely specialized and have lost their ability to divide
- cells that normally do not divide, but can be induced to do so by a stimulus
- cells which continuously undergo cell division
what are cells with a high mitotic rate subject to?
destruction, irritation, and friction
what are some types of cells that are extremely specialized and have lost their ability to divide? and why?
- red blood cells (matured only) (since it has no nucleus)
- neuron (nerve cell) (bc there’s no centrioles)
- muscle cell (cell may increase in size, not in number)
what are some types of cells that normally do not divide but can be induced to do so by a stimulus?
- liver cells
- lymphocytes (white blood cells)
what are some types of cells which continuously undergo cell division?
- skin (constantly replaced)
- cells of the intestinal lining
- bone marrow cells
what does it mean when cells are continuously undergoing cell division?
- it means that they’re flipping through the S phase
- more chances for error in genetic replication
- may lead to mutations
chromosome
- dark- staining, thread-like body in the nucleus
- composed of DNA and protein
- contains genetic information
chromatid
- duplicated chromosome
- hooked together through centromere
gene
unit of DNA that provides the instructions for the production of a specific protein
centriole
- composed of microtubules
- 2 cylindrical structures
- serves as ongoing center for the mitotic spindle
mitotic spindle composition
composed of microtubules
karyotype
- the number and type of chromosomes an individual has
what do the amount of autosomes you have determine?
how well controlled the body structure and metabolism is
how many chromosomes and autosomes does a normal karyotype have?
- 23 pairs of chromosomes (46 total)
- 22 pairs of autosomes
- -> one is a sex chromosome
autosome
-any chromosome that isn’t a sex chromosome
what is the female’s chromosome letters?
XX
what is the male’s chromosome letters?
XY
prophase
- nuclear membrane disappears
- chromosomes become condensed
- centrioles migrate to opposite poles of the cell
- chromosomes split
metaphase
-the paired chromosomes line up along the equator of the cell
anaphase
-the chromosomes separate and migrate to opposite sides of the cell
telophase
- the nucleus divides into two identical cells that have the same composition of DNA
- cytokinesis occurs
what happens during cytokinesis?
- two cells split
- results in two daughter cells
key features of mitosis
- occurs in most cells body
- results in two daughter cells
- daughter cells contain DNA identical to parent cell
- each has 23 pairs of chromosomes = 46 total (diploid, 2n)
key features of meiosis
- occurs in “sex cells” located in the gonads
- results in four daughter cells
- daughter cells contain half the DNA content of parent cell - 23 total chromosomes (haploid, n)
gonads
an organ that produces gametes
Ex: ovary and testes
why would a cell need to adapt?
- in response to stimuli (ex: hormones)
- injury (ex: mechanical friction)
what are some examples of cellular adaptations?
- hypertrophy
- atrophy
- hyperplasia
- metaplasia
- neoplasm
hypertrophy
increase in size of cells
hypertrophy example
muscle cells
atrophy
decrease in size of cells (not trophy)
atrophy example
- muscle reduction
- after a cast is taken off due to lack of use
hyperplasia
increase in mitotic activity and number of cells
metaplasia
changes in cell in response to disease or chronic irritation which results in the transformation of the cell into a different cell type
metaplasia example
cells start to transform as a result to vaping
hyperplasia example
increase in the size of breasts during pregnancy
neoplasm
- “new cell mass”
- rapid multiplication (abnormal)
benign neoplasm example
benign skin tumor; skin lesions
malignant neoplasm example
cancer
neuron
sends information between regions of the brain
what are liver cells also known as
hepatocytes
