Prokaryotes, Eukaryotes, and Cell Evolution: Key Concepts in Biology

What are the two main classes of cells?

Prokaryotes and Eukaryotes

What domains do prokaryotes belong to?

Bacteria and Archaea

What is a key feature of prokaryotic cells?

They do not have a nucleus or membrane-bound organelles.

What is the primary structure that supports prokaryotic cells?

The cell wall and internal rigid protein framework.

How do prokaryotes reproduce?

By binary fission.

What is the genetic material of bacteria typically like?

It is contained in a circular chromosome, often folded into loops.

What additional DNA do bacteria often have?

Plasmids.

What is the main characteristic of eukaryotic cells?

They have a membrane-bound nucleus.

Which domains are included in Eukarya?

Protists, Fungi, Plants, and Animals.

What is the cell theory?

1. All living organisms are composed of one or more cells. 2. Each cell is the structural and functional unit of life. 3. Cells can arise only from pre-existing cells.

Who proposed the first two tenets of the cell theory?

Schleiden and Schwann.

Who proposed the third tenet of the cell theory?

Virchow.

What are exceptions to the cell theory?

Viruses, Viroids, and Prions.

What is a virus?

A small amount of nucleic acids with a protein coat that requires a host cell for reproduction.

What are viroids?

Small circular RNA lacking a protein coat that need host machinery to replicate.

What are prions?

Proteinaceous infectious particles that do not contain nucleic acids.

What is the cytoplasm?

The jelly-like internal fluid environment of a cell, excluding organelles.

What is the central dogma of molecular biology?

The process of DNA being transcribed to RNA, which is then translated into protein.

What is the function of ribosomes?

They are the site of protein synthesis.

What is the structure of ATP?

Adenosine triphosphate, consisting of adenine, ribose, and three phosphate groups.

What distinguishes fungi from other eukaryotes?

They have cell walls made of chitin and are heterotrophs.

What are protists?

A diverse group of mostly single-celled organisms, some of which form colonies.

What is the role of the cell membrane?

It acts as a physical barrier enclosing the cell.

What is the jelly-like internal fluid of a cell called?

Cytosol.

What is the significance of the cell wall in prokaryotes?

It provides structural support and protection.

What is binary fission?

A method of asexual reproduction in which a cell divides into two identical cells.

What type of organisms are included in the domain Archaea?

Microorganisms that often inhabit extreme environments.

What is the primary energy acquisition method for plants?

Photosynthesis, converting light energy into chemical energy.

What is a cell

fundamental unit of life, all organisms are made up of cells

Robert Hooke

first to observe "small chambers" in cork and call them cells.

Anton van Leeuwenhoek

Early light microscopist, improved the magnifying power of microscope lenses

How do we see cells

Light microscopy, electron microscopy, and fluorescence microscopy.

endomembrane system

Builds, modifies and transport cellular materials

Model organisms

non-human species used extensively in research

Model organisms example

Eucherchia coil (bacteria) DNA replication, gene transcription, translation