Intro To Bio Flashcards
What is biology?
The study of life
How do we define life?
Life is a term defined by humans currently, we say something is alive if it satisfies Conditions
5 defining characteristics of living things
- Cellular organization.
- Growth and metabolism.
- Homeostasis.
- Reproduction.
- Heredity.
Cellular organization
Original cell theory
– All living organisms are composed of one (Uni cellular) or many (multicellular) functional units called cells
– The cell is the basic unit unit of life
– Cells arise from pre-existing cells
Modern cell theory
As new discoveries are made theories are modified the modern cell theory also includes the following:
– Energy flow occurs within cells
– Heredity information (DNA) is past from cell to cell
– All cells have the same basic chemical composition
Prokaryote (before a nucleus)
Any cellular organism that has:
– No nuclear membrane
– No organelles in cytoplasm except ribosomes
– Genetic material in the form of a single continuous strand, typically in a loop or coil
Includes: bacteria, archeabacteria
Eukaryote (true nucleus)
Any organism that contains:
– Specialized organelles in the cytoplasm
A membrane bound nucleus, enclosing, genetic material, organized into chromosomes
– And a elaborate system of division by mitosis or meiosis
Includes: plant an animal cells, fungi, and protist
Growth and metabolism
All cells need energy to survive and grow
Metabolism – the sum of total chemical reactions occurring in living organisms
Essentially describes how organisms obtain and use energy
Two different ways organisms can obtain energy
Autotroph and heterotrophs
Autotrophs
– Organisms that can make their own food autotroph can synthesize glucose (an organic simple sugar) process called photosynthesis
– Autotroph occupied the producer level in food chain/web
Includes: some bacteria, algae, and plants
Heterotrophs
– Organisms that must consume organic sugars (glucose) and other molecules to obtain energy
– Heterotroph occupy the consumer and decomposer level in food chains/webs
Includes: some bacteria, fungi, herbivores, carnivores, and omnivores
But once an orgasm has glucose, all organisms use the same process to obtain energy
Cellular respiration
Homeostasis
The ability of an organism to maintain a relatively stable internal environment, despite changes to the external environment
Reproduction
The ability of an organism to make a new copy of itself
Heredity
The transmission of characteristics (DNA) from parent to offspring, thereby preserving features that determine what the organism is and it’s various traits
