Chapter 2 Flashcards
Cells
what are cells?
smallest unit from which all organisms are made
What is a cell membrane?
thin layer surrounding the cytoplasm of every cell
What does a cell membrane do?
controls what enters and leaves the cell
Is a cell membrane particially permeable?
yes
what does particially permeable mean?
allows some molecules & ions to pass through,but not others
What is a cell wall?
a tough layer outside the cell membrane
What is a cell membrane made of?
protein & fat
What is cell wall made of?
cellulose
What does cellulose look like?
fibers, which criss-crosses over one another
Is a cell wall fully permeable?
yes
what does fully permeable mean?
allows all molecules & ions to pass through
What does animal cells never have?
cell walls
What is cytoplasm?
jelly-like material that fills cells
What takes place in the cytoplasm?
metabolic reactions
What is a vacuole?
fluid-filled space inside a cell
What is a cell sap?
fluid that fills large vacuole in plant cells
What is a vesicle?
a very small vacuole,which contains solutions
What is chromosomes?
a very long,thin lengh of DNA
What is a nucleus?
a structure containing DNA in the form of chromosomes
What is DNA?
a molecule containing genetic info
What is chloroplasts?
small structures found inside plant cells
what does chloroplast contain?
the green pigment called chlorophyll
What does chlorophyll absorb?
energy from sunlight
What is starch grains?
tiny pieces of starch,stored in plant cells
