D2 Continuity and Change : Cells Flashcards
Cell and nuclear division, gene expression and water potenial
cell plate
A structure that forms during cytokinesis in plant cells that eventually develops into the cell wall that separates the daughter cells.
oogenesis
The production of mature ovum.
polar body
A small cell that is formed during oogenesis containing a discarded set of chromosomes and minimal cytoplasm.
budding
A form of asexual reproduction in which a new individual organism develops as an outgrowth or bud from the parent organism, eventually detaching to become an independent organism.
diploid cells
Cells that contain two copies of each autosome and two sex chromosomes. Diploid cells have an even number of chromosomes.
haploid cells
A haploid nucleus contains a single set of chromosomes. Gametes are haploid.
homologous pair
Paired chromosomes that have the same genes at the same locations.
biavelant
A pair of homologous chromosomes that come together during prophase I of meiosis. Also known as a tetrad.
phases of mitosis
- prophase
- metaphase
- anaphase
- telophase
non-disjunction
Failure of homologous chromosomes to separate correctly during meiosis I, or failure of sister chromatids to separate correctly during meiosis II.
chiasmata
The physical link between two non-sister chromatids belonging to homologous chromatids, where crossing over occurs.
non-recombinant chromatids
Chromatids that have not undergone crossing over.
recombinant chromatids
Chromatids that have undergone crossing over, resulting in new combinations of alleles.
proliferation
The process of cellular division and replication.
stages of cell cycle
interphase
- G1
- synthesis
- G2
mitosis
cytokinesis
gene expression
The process by which genetic information is used to produce RNA and proteins.
promoter
A non-coding region of DNA to which RNA polymerase binds to initiate transcription.
enhancer
A non-coding region of DNA to which activator proteins bind, facilitating the binding of RNA polymerase to a promoter.
transcription factors
A group of proteins that impact gene expression.
operon
A group of genes that share a promoter.
repressor proteins
Transcription factors that can block the binding of RNA polymerase or other transcription factors to a promoter, downregulating gene expression.
epigenetics
The process by which cells and organisms differentiate through the interaction between DNA and environmental factors.
2 ways epigenetic impact gene expression
- DNA methylation
- histone modification
proteomes
Entire set of protein within a cell or organism.
imprinted genes
Genes that retain their epigenetic tags - about 1% of mammals
hydration shell
The water molecules surrounding and forming hydrogen bonds with dissolved ions in a solution.
hypertonic
A solution that has a higher solute concentration than another solution.
hypotonic
A solution that has a lower solute concentration than another solution.
isotonic
A solution that has the same solute concentration as another solution.
crenated
The state of an animal cell shrivelling and shrinking as a result of water loss.
plasmolysis
The shrinking of the cell membrane away from the cell wall in plant cells due to a loss of water from the cell.
solvent
The medium into which solutes dissolve through solvation.
solute
A substance that is dissolved in a solvent to form a solution.
contractile vacuoles
Organelles found in certain unicellular organisms, such as protoctists, that collect and expel water to maintain an osmotic balance.
water potential
A measure of the potential energy of water, resulting from the solute potential and pressure potential.
potential energy
The stored energy in a system.
root pressure
A hydrostatic pressure generated when mineral ions are actively transported into the root hair cell of a plant, which in turns draws water in by osmosis, creating a pressure which pushes water up the xylem.
formula for water potential
pressure potential plus solute potential
