Practice Set 1B Flashcards
What is the general name for the network of structures within the cytoplasm which support the cell, determine its shape, and participate in movement?
Cytoskeleton
Which three organelles are not surrounded by membranes?
Centrioles
Centrosomes
Ribosomes
An extensive system of cytoplasmic tubules classified as rough or smooth is called the ______.
endoplasmic reticulum
Which endoplasmic reticulum has tubular, branched cisternae, and lacks ribosomes?
Smooth ER
Which organelle adds carbohydrate groups to proteins produced at the endoplasmic reticulum?
Golgi complex
What are the three types of protein structures that contribute to the cytoskeleton?
Microtubules, Intermediate filaments, Microfilaments
What is an example of a membranous organelle?
Nucleus
( ) are the organelles that digest and dispose of worn-out mitochondria.
Lysosomes, lysosomes, or lysosome.
Which membrane-bound organelle is the site of both protein and lipid synthesis?
Endoplasmic reticulum
In a double helix structure of DNA, what are the components A, T, G, C, or maybe even U defined as?
Nitrogenous bases
What is the function of the rough endoplasmic reticulum?
To synthesize proteins.
In the nucleus of a dividing cell, the chromatin condenses so that each ( ), now made of two sister chromatids, can be seen with a light microscope.
chromosome, or Chromosome
The Golgi complex packages cellular products that will be exported from the cell into which structures?
Secretory Vesicles
What is the general name for the network of structures within the cytoplasm which support the cell, determine its shape, and participate in movement?
Cytoskeleton
Which term refers to the protein “spools” that help organize DNA into nucleosomes?
Histones
Which membrane-bound organelle contains a mixture of enzymes that function in digesting foreign matter, pathogens, and expired organelles?
Lysosome
rRNA is short for ( ) RNA.
ribosomal or Ribosomal
What are the monomeric subunits that comprise a molecule of DNA called?
Nucleotides
In the nucleus of a typical human cell, there are 46 DNA filaments. Which term refers to one of these structures?
Chromosome
How are DNA and RNA different?
RNA contains a sugar called ribose whereas DNA contains a sugar called deoxyribose.
RNA consists of only one nucleotide chain whereas DNA is a double helix.
RNA is much smaller. DNA, by contrast, averages more than 100 million base pairs long.
Which organelle adds carbohydrate groups to proteins produced at the endoplasmic reticulum?
Golgi complex
Histones are ( ).
proteins.
tRNA is short for ( ) RNA.
transfer
Which of the following statements are true regarding the DNA structure?
The nitrogenous bases face the inside and hold the two backbones together with hydrogen bonds.
The basic three-dimensional structure of DNA is the double helix.
Each sidepiece is a sugar-phosphate backbone composed of phosphate groups alternating with the sugar deoxyribose.
How are DNA and RNA different?
DNA molecules tend to be much larger than molecules of RNA.
Reason: Molecules of RNA are usually between 70 and 10,000 bases long. Molecules of DNA on the other hand averages over 100 million base pairs long!
Which of the following statements about codons are true?
The genetic code is expressed as a sequence of codons.
A codon is a three-base sequence of mRNA.
Where does the making of mRNA from DNA take place?
In the nucleus
Which term refers to the protein “spools” that help organize DNA into nucleosomes?
Histones
Which molecule contains introns and exons?
Pre-mRNA
This figure illustrates the mechanism of alternative splicing. What is its result?
One gene can code for more than one protein.
A three-base sequence of mRNA is called a(n)
codon, codons, or Codon
Which of the following is a true statement?
Which proteins a cell makes is determined by which genes are activated in that cell.
Histones are ______.
proteins
Which of the following statements are true regarding introns? Select all that apply.
An intron is a portion of mRNA that must be removed before translation.
An intron is a portion of mRNA that does not code for protein.
Alternative splicing helps explain which of the following?
How one gene can produce more than one protein
Which of the following statements about codons are true?
The genetic code is expressed as a sequence of codons.
A codon is a three-base sequence of mRNA.
Which statement best summarizes the role of DNA in protein synthesis?
DNA contains the genetic code that determines the amino acid sequences of proteins.
Which of the following best describes a histone?
A protein component of chromatin that helps to organize and package DNA
Which molecule carries the genetic code from the nucleus to the cytoplasm?
mRNA
Following transcription, only some portions of the mRNA code for the final protein. The sections of mRNA that contain necessary code are called ( ), whereas the mRNA sections that do not code for the final protein are called ( ).
exons/exon or introns/intron
What is the role of mRNA in protein synthesis?
It carries the genetic code from the nucleus to the cytoplasm.
Which molecule contains introns and exons?
Pre-mRNA
During the cell cycle, G1, S, and G2 collectively make up the phase known as what?
Interphase
Name the correct order of the phases of mitosis from beginning to end.
Prophase, metaphase, anaphase, telophase (PMAT)
Translation occurs in three steps. Place these steps in chronological order.
Initiation, Elongation, and Termination
Where does the making of mRNA from DNA take place?
In the nucleus
Indicate what is NOT part of interphase.
M phase, only G1, S and G2
