MMSC 490 Exam 1 PQ Questions

The light microscope was used to observe the cellular structure of cork by ____, who named the chambers "cells".

Hooke

Which fish is proving to be a useful model organism for the study of vertebrate development?

Zebrafish

Arabidopsis thaliana is a model organism for studying the molecular biology of

Plants

The original cell was thought to have arisen from the enclosure of self-replicating ____ by a phospholipid membrane

RNA

The feature that most clearly separates eukaryotes from prokaryotes is the presence of ___ in eukaryotic cells

A nucleus

Chloroplasts are thought to have originated from endosymbiosis of ____ by a large host cell

Photosynthetic eubacteria such as cyanobacteria

The simplicity and clarity of Caenorhabditis elegans allowed researchers to

Trace the developmental lineages of all cells in the adult

Solid tissues in animals include epithelial tissues, ___ tissue, nervous tissues, and muscle

Connective

Studies on which model experimental organism led to the initial discovery of important mechanisms controlling the development of the animal body plan?

Drosophilia melanogaster

The diffraction limited resolving power of a standard light microscope is approximately

0.2 um or Om

How many genes does an E. coli have?

4300

The original atmosphere of Earth is thought to have been rich in

CO2, N2, H2S, & CO

The genome of eukaryotes consists of genes derived from

Both archaebacteria and bacteria

Which of the following is a high-resolution light microscope technique for detecting interactions between proteins?

FRET (fluorescent resonance energy transfer)

Organisms that evolved the ability to use H2O as a donor of electron and hydrogen for the photosynthetic conversion of CO2 to organic compounds radically changed earth by producing

O2

Fluorescent-labeled antibodies are used on cells primarily to locate a specific

Protein

At the time life arose on earth, earths atmosphere contained abundant amounts of all of the following except

O2

Organelles such as mitochondria and chloroplasts are thought to have originated in eukaryotic cells via a process called

Endosymbiosis

The method by which cell components are separated by centrifugation at progressively higher speeds is called ____ centrifugation

Differential

The adult nematode worm Caenorhabditis elegans consists of ___ somatic cells

959

An E. coli cell under well-defined laboratory conditions divides about every

20 mins

Which of the following organelles will be concentrated in the first pellet produced by differential centrifugation?

Nuclei

Which of the following is a colonial organism closely related to the evolutionary precursors of present-day plants?

Volvox

Cytoplasmic organelles are

Absent in prokaryotic cells and present in eukaryotic cells

Which energy-producing process is thought to have come first during cellular evolution?

Glycolysis

Mitochondria and chloroplasts resemble bacteria in that they

Have their own ribosomes, have their own DNA, reproduce by simple division into two

How many genes does the haploid yeast nuclear genome contain?

6,000

The bacterial genome is located in a portion of the cell called the

Nucleoid

The growth factor that stimulates fibroblasts to divide around a wound is released by

Platelets

Living cells are commonly visualized by means of ___ microscopy

Phase-contrast

Stanley miller applied electric sparks to a reducing atmosphere of methane, ammonia, water, and hydrogen, and the resulting products showed that under these conditions

Amino acids can form

The initial importance of a membrane enclosing self-replicating RNA molecules and associated proteins was that it

Maintained these molecules as a unit capable of reproduction and evolution

Which of the following are most commonly used mammals for genetic studies?

Mice

Eukaryotic cell nuclei contain genes that are

Partly archaebacterial and partly bacterial in origin

In fluorescence microscopy, the immediate source of the light detected is light that has been ___ the sample

emitted by

The diffraction limited resolution of a standard light microscope is determined by which of the following equations?

R=0.6 (lamda) / (NA)

In a classic experiment that demonstrated the semiconservative nature of DNA replication, cells were grown first in 14N containing media and later in 15N containing media, and DNA was separated by

Equilibrium centrifugation

Which of the following is not a unicellular eukaryote?

Archaebacteria

RNA is believed to have been the initial genetic system because it can

Catalyze the polymerization of nucleotides into another RNA strand

The source of the atmospheric oxygen necessary for the development of oxidative metabolism is thought to have been

Photosynthesis

Cultures grown from cells of a dissociated tissue are called

Primary cell cultures

The feature that most clearly distinguishes eukaryotes form prokaryotes is the presence of ___ in eukaryotic cells

A nucleus

Drosophila melanogaster was an organism of choice for the study of

The process of development

The eukaryotic nucleus contains ___ DNA molecules

Multiple linear

A few sugars joined together are called a

Oligosaccharide

The unique properties of different membranes are primarily a function of their

Proteins

Lipids play a major role in cells as

Components of cell membranes, part of the cell signaling function, a form of energy storage

In the fluid mosaic model of biological membrane structure, transmembrane proteins are

Embedded nearly randomly in the lipid bilayer

The major bonds in glycogen are ___ glycosidic bonds

a (1 --> 4)

Which of the following store most chemical energy per unit weight?

Lipids

Cholesterol affects the fluidity of membranes by

Decreasing membrane fluidity at high temperatures and increasing membrane fluidity at low temperatures

The interaction of the a and B subunits to form the hemoglobin molecule is an example of ___ structure

Quaternary

Fatty acids are stored in fat droplets in the form of

Triacylglycerols

Complementary base pairs form ___ bonds to direct replication of DNA

Hydrogen

Introducing a double bond into a fatty acid has the effect of putting a(n) ___ into the conformation of the molecule

Kink

RNA in cells can serve as a

Carrier of information from the nucleus to the cytoplasm, regulator of gene expression, catalyst, or enzyme

What is the effect of a beta barrel on the permeability of a membrane?

It increased permeability

In DNA,

G binds with C and A binds with T

Proteins can be covalently modified by the addition of phosphate groups to all but which of the following amino acids?

Arginine

The most abundant molecule in cells is

Water

Molecules that are partly water-soluble and partly water-insoluble are

Amphipathic

Nucleotides have an important function in cells as

Building blocks for nucleic acids, carriers of chemical energy, intracellular signal molecules

Cholesterol, a membrane lipid in animals, has a chemical structure similar to

Estradiol

The three-dimensional structure of a protein is analyzed most definitively by

X-ray crystallography

In polysaccharides, sugars are linked together by means of ___ bonds

Glycosidic

Transport across biological membranes is speeded by what class of biological molecules?

proteins

Sugars can cyclize if they contain __ or more carbons

5

Common factors affecting the fluidity of a membrane include

- number of double bonds in the fatty acid chains

- length of the phospholipid fatty chains

- temperature

Which of the following is not one of the four major classes of organic molecules in the cell?

Water

Phospholipids consist of a 3-carbon core to which fatty acids and a phosphate group are linked. The most common 3-carbon core is

Glycerol

Which of the following is not one of the ways in which DNA differs from RNA?

DNA can form hydrogen bonds with complementary sequences

Sphingomyelin contains two hydrocarbon chains linked to

Serine

What is the major carbohydrate-storage molecule in plants?

Starch

The most common molecules in cellular membranes are the

Phospholipids

Lipids with unsaturated fatty acids

Increase the fluidity of membranes

In the primary structure of a protein, amino acids are joined together by ___ bonds

Peptide

Serine, theronin, asparagine, and glutamine are all __ amino acids

Polar

Which of the following is not a basic amino acid?

Glutamine

Which of the following are involved in forming the tertiary structure of proteins?

-Hydrophobic interactions

-Ionic bonds

- H bonds

Proteins are polymers of how many different amino acids?

20

To clone genes, a plasmid vector should contain a(n)

- Antibiotic resistance gene

- Origin of replication

- Restriction nuclease cut site

The technique by which a particular nucleic acid sequence is localized with labeled probes within a cell, tissue, or isolated chromosome is called ____ hybridization

In situ

Transgenic mice are usually produced by

Injecting DNA containing the gene into the pronucleus of a fertilized egg

Deduction of the structure of DNA was based on a series of key X-ray crystallographic studies done by

Wilkins and Franklin

DNA replicates

Semi-conservatively

Proteins are composed of polymers of amino acids. How many different amino acids are there?

20

A dominant negative mutant is typically one that

Produces a protein that interferes with the function of the protein produced by the normal gene

When introduced into living cells, antisense RNA molecules bind

To complementary mRNA sequences and block protein synthesis

Mutations may be introduced into selected genes of living cells by

Homologous recombination with an altered cloned gene

Which of the following would be used to express a human protein in E.coli?

An expression plasmid containing cDNA made from the mRNA for the protein

When thymidine and adenosine interact within the DNA molecule, they form

Two hydrogen bonds

The experimental introduction of DNA into eukaryotic cells is called

Transfection

DNA can be introduced into cells by

-Electroporation of DNA into cells

-Microinjection into the nucleus of cell

-Fusion of DNA-containing liposomes with cells

DNA was identified as the genetic material in experiments done by

Avery, MacLeod, McCarthy

The first enzymatic step in making a cDNA uses which of the following?

Reverse transcriptase

RNA molecules that serve as template for protein synthesis are called ___ RNAs

Messenger

Vectors for expressing a eukaryotic protein in a bacterium must contain which of the following?

Origin of replication

The most common method of DNA sequencing is based on premature termination of DNA synthesis by inclusion of

Dideoxynucleotides

George Beadle and Edward Tatum provided clear evidence that genes specified the structure for enzymes in a series of experiments on the

Fungus Neurospora

Reverse transcriptase is an enzyme that catalyzes ___ synthesis

RNA directed DNA