BIO Flashcards
pairs of epidermal cells that control gas diusion by
regulating the opening and closure of stomatal pores.
GUARD CELLS
provide an internal hydrophobic surface facilitating water
transport as well as mechanical strength.
XYLEM CELLS
uptake of water and nutrients from the soil
ROOT HAIR CELLS
this enables them to collect more nutrients and water.
Lateral elongation
process of cell growth and division in eukaryotes that is
divided into phases based on what is happening in the
cell at a given time.
The Cell Cycle
the cell is engaged in growth and metabolic activities
and can be further broken down into three discrete
phases called g1, S, and g2.
Interphase
cell grows during the?
G1 PHASE
○ dna replication occurs producing two copies of each chromosome so future cells will each have a
complete set of the genetic instructions in the dna.
S PHASE
after DNA replication is complete, cells enter the g2
phase, they continue to grow & prepare for cell division.
G2 PHASE
cells are not actively preparing to divide.
G0 PHASE
check for nutrients, growth factors, and dna damage
g1 checkpoint
check for nutrients, growth factors, and dna damage
g1 checkpoint
check for cell size and dna replication
g2 checkpoint
check for chromosome spindle attachment
metaphase checkpoint
a complex series of events move the dna so that a
complete set of genetic instructions will be sent to
each daughter cell.
M Phase
the longest phase of mitosis.
PROPHASE
refers to each identical copy of a single chromosome.
SISTERM CHROMATIDS
begin to fan out from two sets of paired structures called
centrioles.
SPINDLE FIBERS
attaches the sister chromatids together.
CENTROMERE
begin to fan out from two sets of paired structures called
centrioles.
SPINDLE FIBERS
⤻ double stranded chromosomes line up along the
equator of the cell.
METAPHASE
⤻ begins when the sister chromatids of each chromosome begin to separate.
ANAPHASE
the longest phase of mitosis.
chromosomes become visible and condense becoming shorter and thicker.
PROPHASE
the longest phase of mitosis.
chromosomes become visible and condense becoming shorter and thicker.
PROPHASE
process of mitosis is assessed at a checkpoint during
the m phase and once this checkpoint is passed, the
cell will complete mitosis as well as begin the?
CYTOKINESIS
4 STAGES OF MITOSIS (PMAT)
PROPHASE
METAPHASE
ANAPHASE
TELOPHASE
grows until it joins with the existing cell membrane
separating the two halves of the cell into daughter cells; over time new cell walls form between the two daughter cells.
cell plate
● sometimes called reduction division
● is the type of cell division that produces gametes; cell
division in sexually reproducing organisms that reduces
the number of chromosomes in gametes.
MEIOSIS
○ sperm cells in males
○ egg cells in females
GAMETES
somatic cells (body cells)
MITOSIS
1 cell division
MITOSIS
two diploid cells (2n) that are genetically identical to
each other
MITOSIS
skin, heart, muscle, liver, and fat cells
MITOSIS
gametes (sex cells)
MEIOSIS
2 cell divisions
MEIOSIS
four haploid (n) gametes that are genetically unique
from each other
MEIOSIS
sperm cell and egg cell
MEIOSIS
● starts with a diploid cell, its chromatin contains two uncoiled spread out sets of chromosomes, one from each parent.
PROPHASE I
process where each chromosome pairs up with and binds to its corresponding homologous chromosome forming a tetrad.
synapsis
is the group of four sister chromatids in paired homologous chromosomes.
tetrad
chromosomes containing genetic information.
were inherited from each parent
genes
different versions of the same gene on each chromosome.
alleles
chromatids from each homologous chromosome exchange segments of alleles, also called recombination
crossing over
results in genetic variety in offspring, this is why children are different from their biological parents as well as from their biological siblings.
crossing over
the homologous chromosomes line up at the equator
and attach to spindle fibers from opposite poles.
METAPHASE I
spindle fibers separate the homologous chromosomes
in each tetrad and pull them to the opposite poles of
the cell
ANAPHASE I
the cell enters telophase one with one chromosome from each homologous pair at separate poles; however each chromosome still consists of sister chromatids.
TELOPHASE I
meiosis one ends with two genetically different haploid
daughter cells, each haploid cell contains only one set
of chromosomes consisting of paired sister chromatids.
CYTOKINESIS
the nuclear membrane disappears and spindle fibers fan out from the two sets of paired centrioles
PROPHASE II
the chromosomes in each cell line up at the equator
and attach to spindle fibers from both poles
METAPHASE II
the sister chromatids of each chromosome separate
and move to opposite poles
ANAPHASE II
spindle fibers disappear and nuclear membranes reform
and cytokinesis occurs in both cells
TELOPHASE II
