Science: What does DNA look like?
When the base on one side of a DNA ladder rung is adenine, the other side of the rung is always
thymine
In what direction does a DNA molecule split during replication?
Down the middle
What happens to DNA every time a cell divides?
It is copied
What are hte four bases of a nuceotide in DNA?
Adenine, thymine, guanine, and cytosine are the four bases.
Who found that adenine is always equal to thymine, and guanine is always equal to cytosine in DNA?
Erwin Chargaff
In a DNA molecule what base sequence is complementary to the sequence CGAC?
GCTG
When Chargaff separated the parts of a sample of DNA, what did he find out about the matching bases?
He found that the matching bases were always in equal amounts.
What two things must the material that makes up genes be able to do?
It must be able to give instructions for building and maintaining cells and be able to be copied when each cell divides.
Why must genes be copied each time a cell divides?
So that each cell contains identical genes and needed information.
What do the four letters scientists often use to refer to the bases of nucleotides stand for?
The four letters are A, T, G, and C and they stand for adenine, thymine, guanine, ,and cytosine
What allows the genetic material for genes to give instructions and be copied before a cell divides?
The structure of DNA allows this to occur.
What did Watson and Crick learn about the fit of the correct pairs of bases within the width of the DNA ladder?
They found that the width of each DNA ladder matches the combined width of the matching bases.
The rungs of the double helix DNA ladder are made of a pair of
bases
In a DNA molecule, pairs of bases are ________________ to each other, since each base always bond with only one other base.
complementary
When the base on one side of a DNA ladder rung is guanine, the other side of the rung is always
cytosine
The twisted shape of DNA is called a
double helix
The subunits that make up DNA are claled
nucleotides
The two sides of the double helix DNA ladder are made of alternating sugar parts and
phosphate parts
The pairing of bases allows the cell to _____________, or make copies of DNA
replicate
What does a nucleotide in a nucleic acid chain consist of?
It consists of a sugar, a phosphate, and a base.
In the cell, what does the job of unwinding, copying, and rewinding the DNA?
Proteins
Who built a model of DNA that helped explain how DNA is copied and its functions?
Watson and Crick
Structures made of protein and DNA and found in the nucleus of cells are called...
Chromosomes
As a DNA molecule splits, what is added to the exposed bases on the original molecule?
Complementary nucleotides
Inherited characteristics are determined by...
Genes
What is another way to say deoxyribonucleic acid?
DNA
Who used x-rays to make images of the DNA molecules, suggesting that DNA has a spiral shape?
Rosalind Franklin
What is DNA?
DNA stands for deoxyribonucleic acid and is the genetic material of all living things that determines the traits. The structure is a double helix shaped like a twister ladder. DNA is made up of sugar and phosphates.
