Part 4 Flashcards
(22 cards)
What is DNA?
A long molecule that consists of hundreds or thousands of genes inherited from parents
What happens to DNA during mitosis?
A copy of its DNA is passed to the next generation of cells
What encodes all of a cell’s activities?
The structure of the DNA molecule
What are the components of a nucleotide?
Nitrogenous base, five-carbon sugar, phosphate group
What is the five-carbon sugar in DNA?
Deoxyribose
What are the two families of nitrogenous bases in DNA?
- Pyrimidines
- Purines
What is a pyrimidine?
There’s one ring (six member ring) and their smaller with two nitrogen atoms
Which bases are classified as pyrimidines?
- Cytosine (C)
- Thymine (T)
What are purines?
Two rings (a six member one fused to a 5 member ring) there larger and have 4 nitrogen atoms
Which bases are classified as purines?
- Adenine (A)
- Guanine (G)
What forms the backbone of the nucleotide strands?
Deoxyribose sugar and phosphate groups
What is base pairing?
The process where two nucleotide chains bond together by their nitrogenous bases
Which bases pair together in DNA?
- A always binds with T
- G always binds with C
Who discovered the structure of DNA?
Watson and Crick
What shape does the DNA molecule form?
A spiral shape called a double helix
What makes up a chromosome?
A DNA molecule and a variety of proteins
How many chromosomes do humans have?
46 chromosomes (23 pairs)
What is a gene?
A series of nucleotides on the DNA molecule that makes up a coded message
What determines the genetic code?
The sequence of nucleotides in a gene
What do groups of genes determine in an organism?
Certain traits
How are traits inherited?
A copy of nucleotide sequences is passed from parent to offspring
What does evolutionary theory suggest about related species?
Closely related species share a greater proportion of their DNA sequences
