Introduction to Biology Flashcards
What was previously believed about biology but soon proven wrong?
spontaneous generation
Recipe for mice - Dr. Jan Bapista von Helmont
Dirty shirt + Wheat + 21 Days = Mice
SOON PROVEN FALSE!!
what is the now readily accepted understanding of how life begins proposed by Francesco Redi?
biogenesis
Redi experiement
Francesco Redi in 1698
He designed an experiment with 3 jars containing meat
jar 1
- Left open, Maggots developed, Flies were observed laying eggs on the meat in the open jar
jar 2
- Sealed from the outside
No maggots developed
jar 3
- Covered with netting, Maggots appeared on the netting, Flies were observed laying eggs on the netting
It was implied that flies were the source of the maggots which lead to the theory of Biogenesis (life from preexisting life)
What are the two types of organisms?
Unicellular: one celled organism (uni=1)
Multicellular: many cells (multi=”many”)
What is the first property of life?
Made up of cells
The cell is the basic unit of life.
A cell is self-contained and possess a barrier (membrane) which separates itself from the environment
The cell is the lowest level of organization that can perform all activities required for life
What is the second property of life?
Living things must reproduce
Must be able to create more of its own kind through reproduction
There are two types of reproduction:
asexual & sexual
What is asexual reproduction?
when a single organism can divide or “bud” to create its offspring without another of its species
What is sexual reproduction?
Sexual: 2 parent organisms combine genetic material to reproduce the offspring
What are two types of reproduction?
asexual & sexual
What is the third property of life?
Living things have genetic material
Instructions for making all the body’s proteins
Located in the nucleus (eukaryotes) or nucleoid region (prokaryotes)
DNA is inherited by offspring from their parents
DNA controls the development and maintenance of organisms
What is the fourth property of life?
Living things must GROW and DEVELOP
What two processes does GROWTH refer too,
in the 4th property
” Living things must GROW and DEVELOP”?
Growth refers to 2 processes:
Increase in the number of cells
Increase in the size of cells
What does DEVELOPMENT refer too,
in the 4th property
” Living things must GROW and DEVELOP”?
Development refers to changes in the organism which occur through its life span including cell differentiation, aging, organ development
What is the fifth property of life?
Living things obtain and use energy:
Energy is used by all living things for development and reproduction
What is sixth property of life?
- Living things must RESPOND (or react) to their environment in some way
Something which causes an organism to react is known as a stimulus (stimuli)
Most responses are geared for maintaining homeostasis
eg. venus fly trap, person responding to heat
