Cell Theory

Question 1

What is cytology?

Answer 1

scientific study of cells, branch of biology

Question 2

Name the scientist according to the year in order.

1660s - F
_____ - R
1670s - A
1830s - R
(book) 1838 - 1842 (essential experimentations) - M
(book) 1838 (established idea) - T
1850s - R (vs R)
1870s - W

Answer 2

1660s - Francesco Redi
_____ - Robert Hooke
1670s - Anton Van Leeuwenhoek
1830s - Robert Brown
_____ - Mathias Jakob Schleiden
_____ - Theodor Schwann
1850s - Rudolph Virchow (vs Robert Remak)
** RV = 1855 “Omnis cellula e cellula”
1870s - Walther Flemming

Question 3

Who created the first compound microscope and when?

Answer 3

Zacharias Janssen (Dutch spectacle maker), 1590

Microscope - arguably most critical instrument used in cellular biology

Question 4

Francesco Redi

• What happened in 1668?

????

Answer 4

1668

debunked Spontaneous Generation/Abiogenesis Theory (proposed by Louis Pasteur) through biological experimentation (involving maggots, flies, meat, lid covers, etc.

proposed 3 hypothesis, concluded that “all living things can only come from living things”….

Question 5

Robert Hooke

• What happened in 1665?

???

Answer 5

1665

observed cork (dead plant cells), coined the term cells (because what he examined looked like empty enclosed boxes like monastic cells)

also created Micrographia - first illustrated book of microscopic observations and the first picture of a cell

scientists were fascinated, but he couldn’t put his finger on the purpose of the cells (since they were dead)

Question 6

What did Robert Hooke see under the microscope?

Answer 6

dead cell walls (organelles disintegrated) !! remember, this was a plant cell, so the cell wall remained intact??

Question 7

Anton Van Leeuwenhoek

book:

• What did he make and when? How much magnification?
• What was the initial purpose of the thing he made?
• First person to observe what?
• So, he is the father of?
• What happened in 1674? (2 things)
• What did he discover about plants (2 things)

class:

• What did he observe? (2 things)

Answer 7

• Made his own single lens microscopes in the 1670s that could magnify up to 270x
• Examine the quality of cloth (he was an amateur scientist and a fabric merchant)
• Microscopic life
• Modern microscopy
• 1674: discovered microorganisms = animalcules, red blood cells
• demonstrated how sap moves, explained plant structures (roots, stems, leaves)

!!! What he saw then is now properly classified today :) (like bacteria, protozoa, rotifers, etc.)

• Pond water and human fluids (including the sperm cell)

Question 8

Robert Brown

• What happened in 1831?

Answer 8

1831

• examined plant cells
• discovered and coined term cell nucleus (opaque spot)
• “frequently central”

Question 9

TS and MS

Answer 9

TS - animals made up of cells
MS - plants made up of cells

Question 10

Rudolph Virchow

Answer 10

cell division

!! vs Robert Remak

Question 11

Walther Flemming

Answer 11

dye –> increased visibility under microscope

discovered changes during cell division

described mitosis (chromosomal behaviors, saw chromosomes in nucleus)

Question 12

Cell Theory

Answer 12

• product of multiple investigations throughout the years involving the microscope and significant biological contributions

Three Tenants

I. All organisms composed of one or more cells
II. Cell is the basic unit of life
III. All cells come from pre existing cells through cell division

*** there are modern principles too (+3)