DNA
Scientists often compare the shape of DNA to a twisted ladder.
What is the scientific name for this shape?
Double helix
DNA stays in the nucleus, but the instructions need to get to the ribosome.
Which molecule carries the instructions from DNA to the ribosome?
mRNA
Before a cell divides, it needs to make another copy of its DNA.
What process does this?
DNA replication
A cell spends most of its life growing, carrying out normal functions, and preparing to divide.
What stage is this?
Interphase
A cell divides and produces two daughter cells that are genetically very similar to the original cell.
Which process is this most likely describing?
Mitosis
A DNA nucleotide has three basic components. Name two of them.
RNA uses a nitrogen base that DNA does not normally use.
What is it?
Uracil
During DNA replication, the two sides of the DNA molecule separate.
What happens next?
New nucleotides based off the pairing rules
During cell division, chromosomes become tightly coiled and visible.
Which phase begins with this major change?
Prophase
Which type of cell division produces cells used in sexual reproduction, such as sperm and eggs?
Meiosis
A DNA strand contains the sequence:
A – T – G – C – C – A
T-A-C-G-G-T
A scientist finds a nucleic acid that contains ribose and uracil and is usually single-stranded.
Is it DNA or RNA?
RNA
If one strand of DNA contains:
C – G – A – T
What sequence would be added to make the complementary strand?
G-C-T-A
The chromosomes line up across the middle of the cell.
What phase is this?
Metaphase
A human body cell normally has 46 chromosomes. How many chromosomes should a normal human sperm or egg cell have?
23
A scientist discovers a section of DNA that contains instructions for making a particular protein.
What is this section of DNA called?
Gene
A cell needs to make a protein. First, it makes an RNA copy of information stored in DNA.
What is this process called?
Transcription
Why is DNA replication important before a cell divides?
New copy is identical to old copy
Sister chromatids are pulled apart and move toward opposite sides of the cell.
What phase is this?
Anaphase
One process involves one cell division, while the other involves two divisions.
Which process involves two divisions?
Meiosis
Explain the relationship between DNA, genes, and chromosomes.
DNA is the molecule containing genetic information. A gene is a section of DNA that contains information for a particular function, often making a protein. A chromosome is a packaged structure made largely of DNA
The ribosome uses the information carried by mRNA to assemble amino acids into a protein.
What process is this?
Translation
A cell begins dividing but its DNA was not copied correctly beforehand.
Why could this cause a serious problem for the new cells?
New cell will not have complete genetic info, can cause errors in normal function
The chromosomes have reached opposite ends of the cell and begin to uncoil. New nuclear membranes form.
What phase is this?
Telophase
Why does meiosis produce cells with half the usual chromosome number?