Flashcards in Mitosis & Meiosis Deck (52)
Types of cell division in eukaryotic organisms
Types of cell division in prokaryotic organisms
What are the functions of mitosis, in both multicellular organisms and in some protists, fungi, plants and animals?
Growth, cell replacement
Some protists, fungi, plants, animals:
List the steps of interphase
G1, S, G2
List the steps of mitosis
prophase, metaphase, anaphase, telophase
The time of normal self functioning and growth
Time when proteins are made for cellular division
What keeps cellular division in check?
Inbuilt molecular break in the G1 phase; once S phase begins, cycle generally runs through G2 and then meiosis. Cancer involves the malfunction of this G1 molecular break, cousin a runaway in the cycle.
What occurs during early, then late prophase?
Early prophase: duplicated chromosomes begin to condense.
Late prophase: new microtubules are assembled, one centriole pair is moved towards opposite pole, nuclear envelope starts to break up.
When does the spindle form?
During the transition to metaphase.
Where do the spindle microtubules attach to the chromatids?
The kinetochore, one on the side of each of the two sister chromatids of each chromosome.
During what phase of mitosis are chromosomes maximally condensed?
During what phase do spindle microtubules become attached to the kinetochores?
Transition to metaphase
During which phase are all chromosomes lind up at the spindle equator?
What are separated chromatids called?
Doing which phase are sister chromatids of each chromosome pulled apart?
What occurs during telophase?
Chromosomes de-condense; two nuclear membranes form: one around each set of under duplicated chromosomes
What are the results of mitosis?
Two daughter nuclei, each with the same chromosome number as the parent cell, in unduplicated form.
When does cytoplasmic division occur?
Generally between late anaphase and the end of telophase.
What is the mechanism for cytoplasmic division in plants?
cell plate formation
What is the mechanism for cytoplasmic division in animals?
cleavage: A contracting ring of actin and myosin microfilaments create a cleavage furrow as they pinch off the phospholipid bilayer.
Pairs of chromosomes that have the same genes but can possess different alleles
(Greek karyon = kernel, seed or nucleus) The number and appearance of chromosomes in the nucleus of a eukaryotic cell, under a light microscope
DNA fibres in a loose state, composed of roughly equal amounts of DNA and protein molecules.
Period of cell growth, when new organelles and molecules are synthesised. By late interphase, much of the DNA has been duplicated, but cannot be seen individually because it is still loosely packed as chromatin.
Miotic spindle begins to form, discreet chromosomes form, appearing no duplicated forms as two sister chromatids connected at the centromere.
Nuclear envelope disappears, microtubules attach to the new kinetochore on each side of the centromere from each end of the miotic spindle.
Miotic spindle fully formed, chromosomes converge equidistantly from the poles of the spindle, known as the metaphase plate. Kinetochores of each chromatid face the poles.