biology chp 4 Flashcards
cell
smallest unit that can carry out all activities associated with life
cells are
building blocks of complex multicellular organisms
cell theory
a unifying concept
cell size and shape are adapted to
function
blank and white blood cells change shape as they move
amoebas
rectangular epithelial cells
stack like building blocks to form sheet like tissues
first described cells in 1665 using a microscope that he had made
robert hooke
discovered bacteria, protists, blood cells, and sperm cells with small lenses that he made
antonie van leeuwenhoek
Dna is located in a
nucleoid
bacteria and archaea are
prokaryotic cells
eukaryotic cells
characterizedby lightly organized and specialized membrane enclosed organelles
cytoplasm
part of the cell outside the nucleus
cytoskeleton
allows a larger size than prokaryotes
nucleus
control center of the cell
nuclear envelope
double membrane that seperates nuclear contents from the cytoplasm
nuclear pores
regulate passage of materials between nucleoplasm and cytoplasm
nuclear lamina
helps organize nuclear contents dna duplication and regulating the cell cycle
include genes that contain coded instructions for protein production
dna molecules
dna associates with rna and certain proteins
chromatim
the nucleus of each human cell has how many chromosomes
46
organells found free in cytoplasm or attached to certain membranes
ribosomes
a network of organelles that exchanged materials through small membrane enclosed transport vesicles
endomembrane system
synthesizes lipids and breaks down toxins
smooth er
synthesizes secreted and membrane proteins
rough er