The Microscopic World of Cells

Flashcards covering key concepts about cells and their structures for exam preparation.

Organisms can be classified as __ or multicelled.

single-celled

All living things are composed of __ according to cell theory.

cells

Prokaryotic cells include __ and Archaea.

Bacteria

Eukaryotic cells include protists, plants, fungi, and __.

animals

Prokaryotic cells are usually __ than eukaryotic cells.

smaller

Eukaryotic cells have __ that perform specific functions.

organelles

The __ is the most important organelle in a eukaryotic cell.

nucleus

A prokaryotic cell lacks a __.

nucleus

The region enclosed by the plasma membrane and nucleus is called __.

cytoplasm

The plasma membrane is composed mostly of __.

phospholipids

Cell walls in plant cells are made from __ fibers.

cellulose

Most animal cells secrete a sticky coat called the __.

extracellular matrix

Ribosomes are responsible for __ synthesis.

protein

The nucleolus is the site where components of __ are made.

ribosomes

The structure that controls what enters and exits the cell is the __.

plasma membrane

Prokaryotes first evolved approximately __ billion years ago.

3.5

Eukaryotes first evolved approximately __ billion years ago.

2.1

The __ of the nucleus allows certain materials to pass in and out.

nuclear envelope

Fibers made of the protein __ hold cells together in tissues.

collagen

The plasma membrane is described as a __ mosaic.

fluid