History of Cells Flashcards
What length is a pearl-string of 20 million ribosomes?
1 metre
Order the following from smallest to largest:
- Fibroblast
- Red blood cell
- Haemoglobin
- Glucose
- Bacteria
- Viruses
- Mitochondria
- Ribosome
- Glucose (smallest)
- Haemoglobin
- Viruses
- Ribosome
- Mitochondria
- Bacteria
- Red blood cell
- Fibroblast
What did Robert Hooke observe under the microscope?
Cork
What did Anthony van Leeuwenhoek discover?
- Bacteria
- Sperm cells
- Free-living protists
- Muscle fibres
Who wrote, in the cell theory, that cells form by free-cell formation?
Matthias Schleiden & Theodor Schwann
Who corrected the free-cell formation theory by stating that all cells arise from pre-existing cells?
Rudolph Virchow
What happens in mitosis during:
a) M-phase?
b) G1-phase?
c) S-phase?
d) G2-phase?
a) M-phase = Chromosome inheritance, cell division
b) G1-phase = Cell growth
c) S-phase = DNA replication
d) G2-phase = Cell growth
Approximately how many cells make up the human body?
10^14
How many neurons make up the cerebral cortex of humans?
10^11 (neurons in the cerebral cortex)
How many red blood cells do humans have?
2-3 x 10^13 (red blood cells in the human body)
What is the five-kingdom classification of life based on?
Morphology
Who introduced the three-domain classification of life?
Carl Woese
What is the three-domain classification of life based on?
Ribosomal RNA sequencing
What happened 4.5 billion years ago?
Formation of the solar system
What happened 4.0 billion years ago?
- Water condensation as Earth cools down
- Formation of Earth’s crust
- Formation of organic molecules
What happened 3.4 billion years ago?
Stromatolites (sediments of fossil cyano-like microbes) indicate first life.
What happened 3.0 billion years ago?
- Photosynthesis developed in cyano-like microbes.
- Oxygen became present in the atmosphere.
What happened 2.0 billion years ago?
Development of eukaryotic cells containing symbiotic prokaryotes.
What happened 1.2 billion years ago?
Appearance of multi-cellularity.
What happened 0.5 billion years ago (500 million years ago)?
The Cambrian Explosion
What happened 230-65 million years ago?
Dinosaurs dominated the Earth.
When did Homo sapiens develop?
0.4-0.25 million years ago
Who developed the ‘central dogma’ model?
Francis Crick
What is a ribozyme?
A catalytic RNA molecule.
