Lecture 122-124

Who improved the microscope in the 1600s?

Antonie von Leeuwenhoek.

What did Robert Hooke do in 1655?

He was the first person to see, describe, and name cells.

What are the three main principles of cell theory?

1. All organisms are composed of one or more cells.

2. Cells are the basic unit of structure and function in organisms.

3. All cells come from pre-existing cells.

What is spontaneous generation?

The belief that life can arise from non-living matter, which was popular in 400 BC.

What is the typical size range of plant cells?

10-100 µm.

Why do cells need to be small?

To maintain a large surface area/volume ratio.

What is the resolving power of a light microscope?

Approximately 0.2 µm.

What does a prokaryotic cell lack that eukaryotic cells have?

A true nucleus and internal membrane-bound organelles.

What are ribosomes responsible for?

Protein synthesis.

What is unique about eukaryotic cells?

They have a membrane-bound nucleus and internal organelles.

What is the function of the plant vacuole?

Storage of amino acids, sugars, wastes, and maintenance of turgor pressure.

What is the powerhouse of the cell?

Mitochondria.

What is the role of chloroplasts?

Photosynthesis in plants and certain protists.

What is the cytoskeleton?

An interconnected system of fibers that provides structure and movement capabilities to the cell.

What are microtubules?

Long hollow tubules composed of tubulin that make up the cilia and flagella and help with movement of chromosomes.

What are cilia?

Short hair-like structures involved in the movement of food particles or water currents, usually present in large numbers.

What is the function of the contractile vacuole in single-celled organisms?

Regulation of water balance.