Chapter 1 Flashcards
Definition of a Cell
Membrane-enclosed units filled with concentrated aqueous substance, endowed with ability to create copies of themselves
There may be up to ______ million distinct species of living things on our plant
100
Calls Vary in Appearance and Function
- A Lactobacillus in a piece of cheese is a few _________ while a frog egg has a diameter of about 1 _________
Micrometers, Millimeter
How are Cells Different?
List 3
1) Size (Lactobacillus vs. Frog Egg)
2) Shape (Nerve Cell vs. Paramecium)
3) Chemical Requirements (Some need O2, for others its deadly)
How are Cells Similar?
List 3
1) Composed of same sort of molecules
2) All contain genetic information in the form of genes that is carried in DNA molecules
3) All carry out Transcription and Translation
4) All obtain energy, grow, and divide
What is the process of a cell reproducing?
Duplicating their genetic material and other compounds, and then dividing in two -> produces a pair of daughter cells
What do proteins do for a cell?
They provide structural support, act as chemical catalysts, molecular motors etc.
How do viruses operate if they cannot replicate by themselves?
They hijack the reproductive machinery of the cells they invade to make copies of themselves
What are mutations?
What do they do to the chances of an organism’s survival?
Mutations are what changes the sequence of nucleotides in the DNA, making daughter cells not an exact replica of their parent
Good Mutation -> Better survival
Bad Mutation -> Elimination of organism
Neutral Mutation -> Tolerates
All Living Cells Have Evolved from the Same Ancestral Cell
Tell the story of this
All living cells inherited their genetic instructions from the same common ancestral cell that existed between 3.5 and 3.8 billion years ago
What is the definition of a Cell’s Genome?
The entire sequence of nucleotides in an organism’s DNA -> provides genetic program that instructs a cell how to behave
How can a Fat Cell, Skin Cell, and Bone Cell have anything in common?
They all stem from the same fertilized cell and contain the same genetic information but express different genes
DNA is identical in every cell
How do Light Microscopes work?
They use visible light to illuminate specimens
How do Electron Microscopes work?
They use beams of electrons because electrons have a shorter wavelength and this allows us to see fine details of cells
What is the Cell Theory
The theory that all living cells are formed by the growth and division of existing cells
Plasma Membrane Definition
An enclosed membrane that separates the interior of the cell from its external enivronment
Cytoplasm Definition
Transparent substance that contains everything within the cell
Ribosome Definition
Complex in which RNA is translated into proteins
Transmission Electron Microscope is used for what?
Looking at thin sections of tissue
What has the simplest structure and comes closest to showing us life stripped down to its essentials?
Bacteria