The Animal Cell Flashcards
eight (8) unifying themes common to all living organisms differentiating them from non-living things
- Living organisms are organized to a hierarchy
- Living things are made up of cell
- Living things acquire and use materials and energy.
- Living things grow and develop
- Living things respond to stimuli
- Living things maintain internal balance
- Living things are able to reproduce in which organisms are able to pass on biological information
- Living things adapt to its changing environment suited for their mode of existence
manifestations of life readily observable
stimulus response
manifestations of life hidden
conversion of light energy to chemical energy in photosynthesis
all characteristics of life are manifested by the _______
cell
it is the basic structure and function of all life forms
cell
all ______ and _________ life processes are carried out by the cell
biological and chemical
when was the cell formally regarded as the basic unit of life
1839
who proposed the cell theory
Matthias Schleiden & Theodor Schwann
very basic way of classifying a cell is based on the presence or absence of the ______ and other __________ within the cell
- nucleus
- compartmentalized parts (organelles)
fourteen (14) subcellular structure of the cell
- cell membrane
- cytoplasm
- nucleus
- ribosomes
- mitochondria
- endoplasmic reticulum
- golgi complex
- lysosomes
- microbodies
- microtubules
- microfilaments
- centrioles
- vesicles
- vacuoles
a double membrane consisting of lipid bilayers with embedded proteins surrounding the cell
cell membrane
a viscous liquid that surrounds organelles
cytoplasm
it is usually located at the center of the cell; round-shaped
nucleus
small round organelles, either free or attached to endoplasmic reticulum
ribosomes
a sausage-shaped organelle with internal foldings and DNA of its own
mitochondria
folded film with or without ribosomes
Endoplasmic reticulum
cellular foldings located near production sites of the cell
golgi complex
small oval organelle filled with digestive juices
lysosomes
electron-dense cytoplasmic particles bound by a single membrane; self-replicating
microbodies
hollow tubes; wall consist of 13 columns of tubulin molecules
microtubules
two intertwined strands of actin
microfilaments
composed of 9 sets of triplet microtubules arranged in a ring
centrioles
small round membrane-bound organelles
vesicles
small to large cellular sacs
vacuoles
stores food, water, wastes and other by-products of the cell
vacuoles
transport materials to where they are needed
vesicles
help organize microtubule assembly;
important in cellular division
centrioles
maintains cell shape, cytoplasmic streaming and cellular motility (pseudopodia)
microfilaments
maintains cell shape, for cell motility (in cilia and flagella) and movement of chromosome in cell division
microtubules
where conversion of fatty acids to sugar takes place
microbodies
digests materials and, in extreme case, is the suicidal bag of the cell
lysosomes
packages newly synthesized proteins for distribution out of the cell
golgi complex
assists with the production and transport of proteins
endoplasmic reticulum
generate most of the cell’s energy in the form of ATP
mitochondria
production centers that make proteins using DNA
ribosomes
control center of the cell, directing all activities within the cellular system
nucleus
site for important chemical reactions
cytoplasm
maintains homeostasis, regulates entry and exit of materials in and out of the cell
cell membrane
unique characteristics of animal cells as compared to plant and bacterial cells
- Centrioles are only found among animals
- Plants and fungi have additional cell walls either made of cellulose or chitin, respectively
- Cells of animals do not have plastids and chloroplasts (since they are heterotrophs)
- Cells of higher animals may be generally grouped into the: somatic cells and reproductive cells.
contain diploid number of chromosomes (2n)
somatic cells
contain haploid number of chromosomes (n) of the given species
reproductive cells
general pattern where the transition of the cell from its normal state of cellular metabolism and growth to the point of cellular division is seen
cell cycle
two (2) basic phases of the cell cycle:
- Interphase
- M phase
three (3) subdivisions of the interphase
- G1
- S
- G2
part of the cell cycle that consumes about 90% of the entire life span of a cell;
where cells grow and develop, readying themselves for potential cellular division
interphase
in this quarter, the cell increasing in size and develop needed organelles and proteins
gap 1 or G1
when the cell achieves the correct size, it proceeds to replicating its DNA in the _____ stage, along with the proteins associated with the DNA molecule
synthesis or S phase
the cell continues to produce the needed chemicals and further grows into a candidate for _____ phase
M phase
a programmed cell death that is triggered if the cell still falls short of required size at the end of repeated trials
apoptosis
importance of the system of checks
- regulates proper cellular function
- avoid the division of defective cells
during this phase, the cell is ready to divide
M phase
during M phase, somatic cells will undergo ______ while reproductive cells will undergo _______
- mitosis
- meiosis
primary goal of mitosis
growth and development
four (4) substages within mitosis:
- prophase
- metaphase
- anaphase
- telophase
state the sub-stage
- appearance of the chromosomes shortening and thickening
- nuclear envelope begins to disintegrate
- nucleolus disappears
- chromosomes are no longer enveloped within the nucleus
- mitotic spindle fibers are then formed from the two centrioles migrating to opposite poles of the cell
- chromosomes attach to the spindle fibers via their kinetochores
prophase
state the sub-stage
chromosomes are guided by the mitotic spindle fibers towards the cellular equator
metaphase
state the sub-stage:
- chromosomes split at the centromere
- each chromosomes, now called chromatids, are pulled apart by mitotic spindle fibers in opposite directions
anaphase
state the sub-stage:
- chromatids are enclosed in new nuclear membranes on either side of the cell
- cytoplasm is divided into two in a process called cytokinesis leading to the formation of two daughter cells
- all other organelles are replicated and distributed to each of them
telophase
does resulting daughter cells have the same number of chromosomes as the mother cell?
yes
defective mitotic division may result to _____
diseases such as tumor and cancer
this disease is characterized by rapid mitotic division
what does the process of mitosis ensure?
the process of mitosis ensures that the chromosome number is maintained in each of the daughter cells produced
goal of meiosis
to produce reproductive cells with half the number of the characteristic chromosomes of a given species called the haploid number (n)
two (2) divisions of meiosis
- reductional division
- equational division
this meiotic division reduces the number of chromosomes into half
reductional division
meiotic division that doubles the number of daughter cells into four
equational division
unique feature of meiosis
crossing over
during this meiotic event, chromosomes exchange genetic materials resulting to new combinations of alleles on a chromosome
crossing over
process of meiotic division in the reductional phase
- prophase I - leptotene, zygotene, pacyhtene, diplotene, diakinesis
- metaphase I
- anaphase I
- telophase I
percentage of time spent during prophase I
90%
important events in prophase I during the reductional phase
- leptotene
- zygotene
- pacyhtene
- diplotene
- diakinesis
chromosomes now move to the equator
metaphase I
bivalent chromosomes disjoin and each of them migrates randomly to opposite poles of the cell;
stage at which random and independent assortment of paternal and maternal chromosomes occur
anaphase I
chromosomes are assembled at the opposite poles as the cytoplasm undergoes cytokinesis;
each daughter cell has the haploid number of chromosomes
telophase I
important event in the reductional phase in which:
- chromosomes condense, thicken and begin to coil up and become visible
- alternating thick areas called chromosomes begin to appear on each chromosome
leptotene
important event in the reductional phase in which:
chromosomes have located their homologs and have paired up to form bivalents
zygotene
important event in the reductional phase in which:
- chromosomes are much thicker and chromatids are now in fours called tetrads;
- non-sister chromatids have exchanged genetic materials in a process called synapsis
pacyhtene
important event in the reductional phase in which:
- paired chromosomes begin to disengage and move apart;
- the side of genetic exchange called the chiasmata move apart
diplotene
important event in the reductional phase in which:
chromosomes move apart in preparation for metaphase
diakinesis
this phase ensues right after telophase I
meiosis II
_______ among males produce four viable sperms at the end of meiosis II
spermatogenesis
______ in females produce one viable egg cell, quipped with all cellular investments, and three other polar bodies which will eventually be re-absorbed
oogenesis