the cell Flashcards
cell is the _____________ & ____________ unit of life
structural
functional
true or false? a cell undergoes repeated division to give rise to an organism
true
example of the cell performing a specialised function in the body
cells of the retina of the human eye convert the light striking it into electric signals that are relayed to the brain. these signals are then translated into the images that a person sees
why are cells called the building blocks of life?
because any function performed by the body is due to the activity of cells in the body
what latin word is the word “cell” derived from? what does it mean, and who first discovered and named it?
the word is cellula
it means small compartment
it was robert hooke
true or false? all life processes take place inside atoms
false. all life processes take place inside cells
four basic features of modern cell theory
1- all living things are made up of one/more cells
2- cells are the basic structural and functional units of all living beings
3- all cells are basically same in chemical composition and metabolic processes
4- all new cells arise by division of preexisting cells
define unicellular organism
living organisms composed of one cell, like amoeba
define multicellular organism
organisms composed of millions of cells, like humans
prime components of a cell?
cell membrane, nucleus, cytoplasm, cell organelles
function of cell membrane
forms an outer boundary; allows only certain substances to enter and move out of the cell; elastic and thus provides stretchability to some extent
cell membrane is also called what in plant cells?
plasma membrane
only __________ cells possess cell wall
plant and bacterial
what is the cell wall made up of
cellulose
function of cell wall
gives shape and rigidity
t/f: cell wall is selectively permeable
false, cell membrane is selectively permeable/cell wall is highly permeable
define nucleus
a small spherical mass present in the centre of the cytoplasm
nuclear membrane is filled with dense __________.
nucleoplasm
nuclear membrane contains thread like structures called ______________________.
chromatin fibre
