DNA Flashcards
(14 cards)
what shape is DNA?
Double helix
what do nucleotides consist of?
A sugar (deoxyribose), a phosphate and a nitrogenous base
what are the four types of nitrogenous base?
Adenine, cytosine, guanine, thymine
how are the nucleotides bound together?
by covalent bonds
what is a gene?
a length of DNA that codes for a protein
what is an allele?
A type of gene that codes for different forms of a protein
what is a genome?
one copy of all and organism’s DNA
How many chromosomes are found in diploid body cells?
23 pairs (46)
how many chromosomes does a haploid cell have?
23 chromosomes (half the diploid cell)
XX
female
XY
male
what does mitosis produce
genetically identical daughter cells (diploid)
what is mitosis used for?
growth, repair and asexual reproduction
what does meiosis produce?
Haploid gametes (sperm, eggs, pollen), not genetically identical
