MITOSIS Flashcards
“Where a cell exists, there must have been a pre-existing cell, just as the animal arise only from an animal.”— name and year
Rudolf Virchow, 1855
Omnis cellula e cellula
every cell from a cell
The continuity of life based on the reproduction of cells
cell division
Functions of cell division
- asexual reproduction
- growth and development
- tissue renewal
example of asexual reproduction
amoeba, a single-celled eukaryote
example of growth and development
sand dollar embryo
example of tissue renewal
bone marrow cells
the cell division process is an integral part of—
cell cycle
the life of a cell from the time it is first formed during division of a parent cell until its own division into two daughter cells
cell cycle
why do biologists use the words sister/daughter in relation to cells
there is no relation
crucial function of cell division
passing identical genetic material to cellular offspring
reproduction of cell involves…
distribution of identical genetic material-DNA-to two daughter cells
a cell’s DNA, it’s genetic information is called
genome
in a typical human cell, what is the length of DNA, and about how many times is it greater than its diameter?
2 meters; 250,000 times greater
greek words and their meanings of “chromosomes” and the reason behind it
chroma - “color”
soma- “body”
reason: they take up certain dyes used in microscopy.
building material of chromosomes
chromatin
a eukaryotic chromosome consists of ________ associated with many ______.
one very long, linear DNA; proteins
the units of information that specify an organism’s inherited traits
genes
true or false: The DNA molecule carries several hundred to a few thousand genes.
true
functions of associated proteins of the chromosomes
maintains the structure and help control the activity of the genes
what are somatic cells?
all body cells except the reproductive cells
the nuclei of a human somatic cells contains how many chromosomes?
46
these cells have half as many chromosomes as somatic cells
gametes (reproductive cells)
how many chromosomes (somatic) are there in a
- cabbage plants
- chimpanzees
- elephants
- hedgehogs
- alga
respectively; 18 48 56 90 148
when a cell is not dividing, each chromosome is in the form of..
a long, thin chromatin fiber
after DNA replication, the chromosomes…
condense
each duplicated chromosome consists of ____ which are joined ___
two sister chromatids; copies of the original chromosome.
protein complexes that attaches two identical DNA all along their length _____ - this attachment is called __
cohesins; sister chromatid cohesion
a region made up of repetitive sequence in the chromosomal DNA where the chromatid is attached most closely to its sister chromatids
centromere
other bound proteins condense the DNA, giving the duplicated chromosome a
narrow “waist”
the portion of a chromatid to either side of centromere is referred to as an
arm of the chromatid
the division of the genetic material in the nucleus
mitosis
division of the cytoplasm
cytokinesis
meiosis occurs only in
special cells in the ovaries or testes (gonads)