Review 2 Flashcards
what is genome
the complete genetic material of an
organism (i.e. all DNA)
what is prokaryotic genome
single, double-stranded
DNA molecule in the form of a loop or circle.
what is eukaryotic genome
several double-stranded,
linear DNA molecules bound together with
proteins to form complexes called
chromosomes
* Each species of eukaryote has a different
number of chromosomes in the nuclei of its
cells
* E.g. human body cells (somatic cells) have 46
chromosomes (23 pairs)
what is diploid
when a cell contains two matched
sets of chromosomes
what is haploid
: when a cell has only one set of
chromosomes and is designated n
* Found in sex cells of eukaryotic organisms
* Gametes (sex cells) contain only one set of
chromosomes
* E.g. Human gametes (e.g. egg or sperm) contain
one set of 23 chromosomes
* Somatic cells in some organisms are haploid, but
this is rare (e.g. male bees, ants)
what is homologous chromosomes
the matched pairs of
chromosomes in a diploid organism
what is locus
the location at which specific nucleotide
segments are placed on a chromosome
what is gene
the functional unit of a chromosome,
which determines specific characteristics by
coding for specific proteins.
what is traits
the different forms of a characteristic.
* E.g. in humans: shape of earlobes is a
characteristic, free/attached are traits
* E.g. in humans, eye colour is a characteristic,
blue/green/brown/hazel/etc. are traits
what is the cell cycle
series of events involving cell
growth and cell division that produces two
new daughter cells.
what happens during interphase
the cell grows and DNA is
replicated (longest phase)
The cell undergoes normal processes while also
preparing for cell division.
* For a cell to go from interphase to the mitotic
phase, many internal and external conditions
must be met.
* Three stages of interphase: G1, S, and G2
The first stage of interphase
* Called G1 (or first gap) because little change is
visible.
* At biochemical level, cell is accumulating
building blocks of chromosomal DNA and
proteins, and enough energy reserves to
replicate each chromosome in the nucleus
What happens during Interphase: G1 phase
The first stage of interphase
* Called G1 (or first gap) because little change is
visible.
* At biochemical level, cell is accumulating
building blocks of chromosomal DNA and
proteins, and enough energy reserves to
replicate each chromosome in the nucleus
What happens during interphase: S phase
S phase (synthesis phase)
* DNA replication results in the formation of two
identical copies of each chromosome (called
sister chromatids) that are firmly attached by a
centromere
* Centromere is duplicated, which allows
mitotic spindle to develop
* these orchestrate the movement of
chromosomes in mitosis and helps organize
cell division
What happens during Interphase: G2 phase
- G2 phase (second gap phase)
- cell replenishes its energy stores and makes the
proteins necessary for chromosome
manipulation. - Cell may grow
- Some cell organelles are duplicated, and the
cytoskeleton is taken apart to form the mitotic
spindle
what happens during mitotic phase
he replicated DNA and
cytoplasmic contents are separated and the
cell divides
Divides the contents of the nucleus and
cytoplasm to make two identical daughter
cells
* A process in which duplicated chromosomes
are lined up, separated, and moved to
opposite ends of the cell, and then the cell is
divided into two new identical daughter cells.
