Unit 1 - Topic 5 Flashcards
DNA
Deoxyribonucleic acid
Molecule storing genetic info for heritable traits
Directs structures and functions of cells
Genetic material
Found in nucleus
DNA functions
Controls formation of cells
Controls products cells release
Controls everything cells do
Chromosomes
Tightly packed strands of DNA visible under a light microscope during cell division
Structure of DNA
Shape of coiled ladder
Components of DNA
Sides of ladder -> alternating subunits called sugars and phosphates
Rungs of ladder -> pairs of nitrogen bases
Nitrogen bases
Adenine (A)
Thymine (T)
Guanine (G)
Cytosine (C)
Nitrogen base pairs
A forms chemicals bonds w/ T
C bonds w/ G
Nucleotides
Each made of phosphate, sugar, and a nitrogen base
Amount of nucleotides in DNA
Thousands
Gene
Section of DNA on chromosome that codes for specific protein and function
Human genome
Total code for human DNA
Contains about 3.0 x 10^9 pairs of bases
Genes per person
30 000
Typical gene having … base pairs
3000
Chromosomes in dogs and tomatoes
78
24
Cells in multicellular organisms divide for
Growth of organisms
Repair and replacement of tissues
Somatic cells
Body cells, not including reproductive cells
30-50 yrs
Brain cells
120 days
Red blood cells
2 days
Stomach lining cells
200 days
Liver cells