Cell Communication & Signaling
Earl W. Sutherland discovered that cell signaling involves these three stages.
What are reception, transduction, and response?
These identical copies of a duplicated chromosome are attached along their lengths by cohesins.
What are sister chromatids?
The initial crossovers formed between homologs in meiosis form these x-shaped structures going into metaphase I.
What is/are chiasmata?
This process describes programmed cell death that prevents damage to neighboring cells and is vital in development.
What is apoptosis?
This event restores the diploid number in animal cells.
What is fertilization?
These connections allow direct cytoplasmic exchange/communication between adjacent animal and plant cells.
What are cell junctions (gap junctions or plasmodesmata)?
DNA is duplicated during this specific subphase of interphase.
What is the S phase (synthesis phase)?
Different forms of genes.
What are alleles?
This term describes the spread of malignant cancer cells to other parts of the body.
What is metastasis?
This is the number of possible combinations of chromosomes as a result of meiosis (just gamete formation) in humans.
What is 223 (~8 million)?
This term describes the process where phosphorylation and dephosphorylation act as a molecular switch for protein activity.
What is a phosphorylation cascade?
This enzyme cleaves cohesins during anaphase, allowing sister chromatids to separate.
What is separase?
The process of homologs lining up preparing to exchange genetic information.
What is synapsis?
This part of meiosis separates homologs.
What is anaphase I?
Name three mechanisms of genetic variation that stem from meiosis and/or sexual reproduction.
What are random fertilization, crossing over, and independent assortment?
This small molecule, produced from ATP by adenylyl cyclase, is one of the most common second messengers.
What is cyclic AMP (cAMP)?
This specific site on each chromatid attaches to spindle microtubules during prometaphase.
What is the kinetochore?
This part of meiosis separates sister chromatids.
What is anaphase II?
When crowded cells stop dividing due to limited space, they are demonstrating this type of external regulatory mechanism.
What is density-dependent inhibition?
This cyclin-Cdk complex triggers a cell’s passage past the G2 checkpoint into mitosis.
What is MPF (maturation-promoting factor)?
These two additional second messengers are produced from cleavage of a phospholipid and help release calcium ions into the cytosol.
What are inositol trisphosphate (IP3) and diacylglycerol (DAG)?
These radial arrays of short microtubules extend from each centrosome during mitosis and help anchor the spindle.
What are asters?
The period of time between meiosis I and II divisions.
This process allows bacteria to sense local population density and coordinate behaviors such as biofilm formation.
What is quorum sensing?
A banana cell (3n = 22) is in anaphase of mitosis. At this point, it has this many chromosomes.
What is 44?