Lesson 1 - DNA Flashcards
1
Q
the structure of DNA
A
- has a spiral shape (helix)
- the two “supports” are sugar-phosphate molecules
2
Q
how DNA is packaged
A
- dna is tightly coiled around proteins called histones
- the dna and histone packages form structures called nucleosomes
- as a cell prepares to divide, the chromatin thicken and shorten to become chromosomes
3
Q
how is DNA is replicated
A
- the DNA unwinds and unzips
- the appropriate bases pair up with each strand, these joined to their sugar - phosphate backbone, create two perfect DNA copies
4
Q
mutation
A
a change in DNA of an organism
5
Q
mutagen
A
a substance or factor that can cause mutation in DNA
6
Q
karyotype
A
photograph or chart
7
Q
somatic
A
human body with 46 chromosomes
8
Q
autosomes
A
non-sex chromosomes
9
Q
how many chromosomes do humans have
A
46 chromosomes
23 pairs
