Cell: Unit of Life Flashcards
Define Cytology
Study of cell and cellular structure
What is the difference between unicellular and multicellular organisms?
Unicellular: Single-celled, Independent existence, can perform all the essential functions of life.
Multicellular: Component of many cells
Give an example of unicellular organisms
Bacteria or Amoeba
Give an example of multicellular organisms
Humans, buffalo, etc.
Who discovered the cell?
Robert Hooke
What type of cell did Robert Hooke discover?
He saw a cell wall of a dead cell and not the cell.
Did Robert Hooke observe a living cell?
No
Who first saw and described the living cell?
Anton von Leeuwenhoek
Who discovered the nucleus?
Robert Brown
Who were the three scientists who formulated the cell theory?
Matthias Schleiden, Theodore Schwann and Rudolf Virchow
Whats was the cell theory?
- All living organisms are composed of cells and their products
- Cell is the structural unit of life.
- New cells arise from preexisting cells.
Which statement described by Rudolf Virchow explained the formation of new cells?
Omnis cellula-e-cellula
Name the smallest cell
Mycoplasma
What are the features of mycoplasma?
Mycoplasma can survive without O2 and without a cell wall.
What is the largest cell?
Ostrich’s egg
Name the smallest cell in the Human body
RBC
Name the largest cell in the human body
Ovum
Name the longest cell in human body
Nerve cell
Difference between Prokaryotic and Eukaryotic cell, INCLUDE EXAMPLES
Prokaryotic Cell 1. Lacks membrane-bound nucleus. 2. Lack membrane-bound cell organelle Eg: Cyanobacteria/BGA, Bacteria and Mycoplasma Eukaryotic Cell 1. Have a membrane-bound nucleus. Have a membrane-bound organelle Eg: ER, Mitochondria, Golgi Bodies, Lysosomes.
Bacteria are of what types and what are their shapes?
Bacillus (Rod-shaped)
Coccus ( spherical shaped)
Vibrio (comma-shaped)
Spirillum (Spiral shaped)
What is the cell envelope made out of? list in order, first being the outer shell and last being the inner shell.
- Glycocalyx
- Cell Wall
- Plasma Membrane
What are the different ways glycocalyx can be around the cell?
Glycocalyx can be LOOSELY packed —> SLIME LAYER
Glycocalyx can be TIGHTLY packed —–> CAPSULE
What is a dense membrane-bound structure?
Nucleus
What are chromosomes?
they are genetic material (DNA) inside the nucleus
Which types of cells have membrane-bound nuclei?
Eukaryotic
A semi-fluid matrix occupying the volume of cell
Cytoplasm
Which types of cells lack membrane-bound nuclei?
Prokaryotic
Which organelle is non-membrane-bound and is in both prokaryotic as well as eukaryotic cells?
Ribosomes
Name all the non-membrane-bound organelles in animal cells.
Ribosomes and centrosome
Which organelle helps in cell division
centrosome
What is the length of Mycoplasma
0.3 micrometer (µm)
What are the different types of shapes of cells?
Disc-like, polygonal, columnar, cuboid, thread-like, or even irregular.
What is an example of mycoplasma?
PPLO
Pleuro Pneumonia like organism
What is the cell wall made of?
Peptidoglycan
What makes up the plasma membrane?
phospholipid and protiens
Some basic features of the prokaryotic cells…
- cytoplasm, cell organelles, and inclusion bodies
2. Naked genetic material, genomic DNA (single-stranded)
Describe the features in the cell wall of prokaryotic cells
- It determines the shape of the cell
- Provides strong structural support to the cell
- Prevents bacteria from collapsing or bursting
Describe the features in the plasma membrane
- semi-permeable membrane
2. structure similar to eukaryotes (phospholipids and proteins)
“Many bacteria have small circular DNA outside the genomic DNA. These smaller DNA are called _________”
Plasmid
“These Plasmids contain___________ characteristics to bacteria” give an example
Phenotypic
Eg: they give resistance to antibiotics to bacteria
What is the essential folding in the prokaryotic cells called?
Mesosomes
how are mesosomes formed?
They are formed by the extensions in the plasma membrane into the cell. They are formed in the form of vesicles, tubules, and lamella.
What are the functions of mesosomes?
Helps in
- cell wall formation
- DNA replication and distribution to daughter cells
- In respiration
- secretion
- Increase the surface area of the plasma membrane
- Increase in enzymatic content.
What are chromatophores?
They are membranous extensions in the cytoplasm