QUIZ 4 Flashcards
Any sexually reproducing multicellular organism begins as a ____ entity.
single-celled
___ relies on cellular events to produce more cells, the early stage of which is shown in the blastula
single-celled entity
Almost every cell in our bodies has genetic material in the form of _____
deoxyribonucleic acid (DNA).
the primary genetic material of living organisms, stores genetic information in the sequences of its nucleotides.
DNA
Positively charged ____ proteins aid in DNA packaging
histone
___ DNA is found in the form of chromatin, a complex of DNA and proteins.
Interphase
Chromatin will sometimes need to further condense into a highly coiled and compact structure. This highly condensed form of DNA is known as a
chromosome.
Humans have __ individual (or ___ pairs of) chromosomes.
46, 23
___ condenses into ____. Each half of the _____ is a _____.
Chromatin, chromosomes, chromosome, chromatid
The life cycle of a cell is known as the ___
cell cycle
involves different phases that constitute a series of preparations for a cell to divide to produce new cells.
Cell cycle
3 Stages of Cell cycle
● Interphase
● M-phase
● Cytokinesis
Events on the interphase
● Gap 1 phase
● S phase
● Gap 2 phase
● Gap 0 phase
● Growth of cytoplasm and doubling of organelles
● Produce proteins, enzymes, nutrients, and energy
● Highest rate of protein synthesis
● Movement of centrioles of the centrosomes away to await and assist the events of mitosis
GAP 1 PHASE
● This stage is named so because it is when the cell synthesizes a copy of its DNA in a very notable process called DNA replication.
S-Phase
This refers to the event when an existing DNA produces another copy of itself.
DNA replication
DNA REPLICATION
- Portion of DNA
- DNA seperate
- Nucleotides attract to their complementary bases
- Nucleotides have lined up
- All nucleotides are joined
● Continued growth and the production of materials that are necessary for cell division to occur
● Protein synthesis but not at the rate similar to that of the G1 phase
GAP 2 PHASE
involves either one of two processes, namely, mitosis and meiosis.
M-PHASE
___ (somatic / body cells)
mitosis
____ (sex cells /gametes)
meiosis
● is marked by the formation of a cleavage furrow in animal cells.
● is marked by the formation of a cell plate in plant cells.
● refers to the division of the cytoplasm.
● can only occur once the genetic material is properly distributed to the daughter cells.
Cytokinesis
refers to the division of the nucleus and genetic material.
Mitosis & Meiosis
Cell cycle check points
- G1-to-S checkpoint
- G2-to-M Checkpoint
- Metaphase Checkpoint
● Is there any damage in the cell’s DNA?
● Is the cell large enough with all the necessary energy reserves and doubled organelles?
G1-to-S Checkpoint
● Are the environmental conditions favorable for cell division to take place?
● Is the DNA properly replicated?
● Is there a presence of DNA damage?
G2-to-M Checkpoint
● Are the spindles properly attached?
M Checkpoint
