exam 2 HW Q's Flashcards
(98 cards)
Which component of a phospholipid is found in the interior of a lipid bilayer?
fatty acids
A protein on a cell surface that binds to a signaling molecule is an example of which of the following elements of cellular communication?
a receptor protein
Which of the following types of cellular activities can be a response to cell signaling?
Cell division is triggered
gene expression patterns are changed
enzyme activities are changed
cell signals are released to communicate with other cells
How does an ‘activated’ receptor transfer information into the cell?
through a conformational change of the receptor
On early earth, approximately 3.5 billion years ago: the first microbial mats (biofilm aggregations of prokaryotes) likely harvested energy through what?
redox reactions from chemicals found near hydrothermal vents.
Bacteria and Archaea generally can live…
in most environments on earth - including many regions with extreme conditions.
Unlike with animals, artifacts in the fossil record of bacteria and archaea offer very little information for analysis. Fossils of ancient prokaryotes look like tiny bubbles in rock.
How might scientists investigate their evolution and diversity in view of this challenge?
Scientists can make comparisons between DNA sequences in living bacteria and use this information to generate hypotheses about the organisms’ evolutionary relationships.
A theory that the complex eukaryotic cells of today arose through the combination of prokaryotic species into one.
Theory of Endosymbiosis
A type of cell that is lacking a nucleus or any other kind of membrane-bound organelle.
prokaryote
Evidence of earlier life on earth preserved in rock, dirt, or amber
fossil records
A type of cell containing a membrane-bound nucleus as well as other organelles.
Eukaryote
A small circular bit of DNA that is passed between bacteria during conjugation - allowing the exchange of genetic information.
Plasmid
Found in Eukaryotic cells, Examples include the nucleus, lysosome, mitochondria, and chloroplasts.
Membrane Bound Organelles
A type of prokaryote that generally reproduces asexually through binary fission, but can sometimes pass genetic information to other similar prokaryotes.
Bacteria
The process of genetic exchange in bacteria where one donor bacteria passes a plasmid to a recipient.
Bacterial conjugation
Membranes help the cell to maintain different concentrations of some substances on the two sides of the membrane. How could these ‘electrochemical gradients’ be used by the cell in practical ways?
Electrochemical gradients could be used to control the internal chemistry of the cell.
The electrochemical gradients could be harnessed work as a kind of battery for the cell.
Which of the following are parts of the endomembrane system?
The Endoplasmic reticulum
The Golgi Apparatus
The Lysosomes
What are 3 basic functions of membranes?
Act as a barrier to keep some compounds from moving in and out of the cell.
Be permeable in a selective way to receive or transmit certain compounds.
Receive and transmit signals from the environment to the interior of the cell.
What are 3 compounds found in cell membranes?
Phospholipids
Proteins
Cholesterol
Diffusion is an example of _____________ transport into the cell.
Passive
Which of the following components of the cytoskeleton are primarily utilized in cell motility and muscle contractions?
Actin
Cancer can arise from what
Homeostatic imbalances in cell function and failures in cell cycle checkpoints.
Over-active proto-oncogenes Underactive tumor suppressor genes
The cytoplasmic division of a cell at the end of mitosis or meiosis, bringing about the separation into two daughter cells.
Cytokinesis
The result of meiosis: a reproductive cell with a single set of unpaired chromosomes
Haploid Cells