Histones are found in
1. proteasomes. 2. lysosomes. 3. vesicles. 4. endosomes. 5. nucleosomes.
Most of a cell’s DNA is located in its
1. Golgi apparatus. 2. lysosomes. 3. ribosomes. 4. nucleolus. 5. nucleus.
The functional units of DNA that contain the instructions for making one or more proteins are ribosomes. RNA. chromosomes. codons. genes.
genes
The nucleus is surrounded by the ________.
nuclear envelope
DNA \_\_\_\_\_.
contains uracil
is processed to remove introns
is non-complementary
is transcribed into RNAis transcribed into RNA
The set of three nucleotides on the mRNA strand that are read by the ribosome is termed the \_\_\_\_\_\_\_. "codon" "tRNA" "anti-codon" "triplet"
codon
Which enzyme transcribes DNA? DNA transcriptase RNA polymerase DNA polymerase RNA reductase
RNA polymerase
Transcription directly results in the formation of \_\_\_\_\_\_\_\_\_\_. DNA messenger RNA histones All of these
messenger RNA
A mature red blood cell lacks a nucleus; therefore, it
1. is malformed. 2. can only divide once more. 3. can repair itself readily. 4. cannot make new proteins and will be worn out within a few months. 5. will be a long-lived cell.
The process of protein formation directed by mRNA is called replication. auscultation. translation. transcription. mitosis.
translation
The anticodon for the triplet UCA is AGC. AGT. TGT. AGU. TCA.
AGU
Before the mRNA transcribed from a gene can be used to translate into a protein, it must be
1. edited to remove introns and transported into the cytoplasm. 2. coated with phospholipids for transport out of the nucleus. 3. edited to remove introns. 4. transported into the cytoplasm. 5. edited to remove exons.
The molecule that brings the proper amino acid into place at the ribosome for the elongation of a new protein is called ATP. mRNA. Na-K. tRNA. rRNA.
tRNA
Thymine is replaced by which nitrogen base in RNA? guanine thymine is not replaced in RNA uracil cytosine ribose
uracil
The duplication of DNA is called ________, the copying of DNA to mRNA is called ________, and the reading of the mRNA by the cell to make a protein is called ________ .
1. reproduction, duplication, initiation
2. replication, transcription, translation
3. mitosis, duplication, protein synthesis
4. replication, translation, transcription
5. interphase, replication, active transportRibosomes are composed of protein and ________.
RNA
The enzyme ________ is required for the synthesis of mRNA.
RNA polymerase
The start of each gene begins with a ________ segment.
promoter
Permanent alterations in a cell’s DNA that affect the nucleotide sequence of one or more genes are called ________.
mutations
Which of the following best explains diffusion?
Which of the following is most likely to move through the cell membrane by facilitated diffusion? CO2 Na+ O2 small lipids
Na+
What is the basic difference between simple diffusion and facilitated diffusion across a cell membrane?
1. In simple diffusion, molecules move down the concentration gradient but in facilitated diffusion molecules move up the concentration gradient. 2. In facilitated diffusion, molecules only move with the aid of a protein in the membrane. 3. Simple diffusion requires molecules to move through special doorways in the cell membrane. 4. Simple diffusion is passive but facilitated diffusion is an active process that uses energy.
Which of the following is least likely to increase the rate of diffusion? small molecule size small concentration gradient higher concentration of molecules high temperature
small concentration gradient
Which of the following is not required for osmosis to occur? water concentration gradient energy selectively permeable membrane
energy