Diversity Flashcards
What are the characteristics of living organisms?
– Composed of cells
– Growth and development.
– able to reproduce
– respond to their environment
– adapt to their environment
– obtain and use energy
– produce wastes
In which kingdom would you place viruses?
•Viruses do not belong in any of the six kingdoms.
Why
– because they cannot survive outside of living cell
– they have DNA or RNA but need a host cell to replicate
– They are not cellular . They have no cell membrane cytoplasm or organelles.
• outside of a cell viruses are lifeless chemicals
Viral infection– lytic cycle
Viruses must enter a cell in order to replicate (make copies of themselves). This is called the lytic cycle. When the host cell bursts and release the viruses (called lysis) it dies
Viral infection – lysogenic cycle
– Sometimes the viral DNA enters the cell and becomes part of the house DNA. This new unit is called a provirus.
– the viral DNA remains dormant and does not cause disease.
– the viral DNA may be activated breaking off the host, DNA and entering the lytic cycle, causing disease.
The four major groups of macromolecules are:
- Carbohydrates.
- Lipids.
- Proteins.
- Nucleic acids.
Carbohydrates
– Based upon a carbon ring with hydrogen and oxygen
– Most are polymers of the monomer glucose
Monosaccharides
Single ring sugars very quick energy source
– Glucose(fuel to power, cellular, respiration in nearly all living things)
– Fructose (fruit sugar)
– Galactose (milk sugar)
Polysaccharides
From 10–1000s of monosaccharides joined together
Starch – storage form of glucose in plants ex breads, rice, potatoes
Cellulose – tough material used in plant cell walls. Humans can’t digest fibre
4 different classes of lipids
a) triglycerides
– what we typically call fatty acids
– contain twice as much energy per gram and carbs or proteins
b) phospholipids.
– Naturally formed by layers when placed in water
c) steroids
– Cuticle of plants made up of fatty acids to reduce loss of water from leaves
– Bees use waxes to build honeycombs
Proteins
– chains of similar monomers called amino acids
– Form the most complex molecules in living things
– There are 20 different amino acids we use in our body
Functions :
– Control the movement of material in and out of the cell
– Enzymes – speed up the rate of biochemical reactions in cells
– Structural component of hair, nails, muscles, collagen, etc.
Nucleic acids
– A polymer of similar monomers called nucleotides
– 100s -> millions of nucleotides long per molecule
Comparison between RNA and DNA
– DNA replicates and stores genetic information
– RNA converts the genetic information to a format used to build proteins
What is biodiversity?
■ From simple beginnings, life on Earth has become more diverse and more complex over time
○ Original single-celled ancestors of all living things has given rise to millions of species
○ Macroevolution: the large scale evolutionary changes that gave rise to new species
■ Biodiversity relates to the number of species on Earth
○ The more, the better!
○ More unique species=less competition as individuals become uniquely adapted to specific ecological niches
Taxonomy
Definition:
■ science of classifying organisms
(both living & extinct)
Purposes of Taxonomy:
1. to identify organisms
2. to represent evolutionary relationships among them
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Levels of classification
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
