Chapter 1 - Science Of Life Flashcards
How long ago did life arise on earth?
Approximately 3.5 billion years
Describe the first organisms:
Single celled, the only life on earth for millions of years
Organisms change or ______ over long periods of time
Evolve
Today, millions of ______ of organisms exist on earth
Species
The ______ is the basis unit of life and makes up all ______
Cell, organisms
______ organisms are made of a single cell and are genetically ______ to their parent cell
Unicellular, identical
Many-celled organisms are called ______ and they may be made of ______ types of cells
Multicellular, different
All cells are not alike, have different characteristics
What is the size of a cell?
Very small, in general all are small, large organisms just have more organisms
Are cells organized?
highly organized even though they’re chaotic
Specialized structures in cells are called ______
Organelles
What surrounds cells?
Plasma membrane
All cells must contain a set of ______ or DNA
Instructions
Tells the cell how to do its role + reproduce, genetic coding
Organisms maintain stable internal conditions called ______
Homeostasis
Very stable internal conditions
Example of homeostasis:
Temperature, water content, blood sugar, etc.
For a species to continue, some of its members must be able to ______ and pass on their traits to their ______
Reproduce, offspring (inheritance)
What does DNA stand for?
Deoxyribonucleic Acid, genetic information in all cells
DNA’s instructions are called ______ and code for the complex ______ necessary for life
Genes, proteins
______ cells or body cells each have a full set of DNA or hereditary information from ______ parents
Somatic, both
Not every cell uses the coding they have
______ reproductions combine hereditary information from ______ parents
Sexual, both
Two different organisms combined
When a sperm and egg join, a fertilized egg or ______ forms and contains DNA from ______ parents
Zygote, both
In ______ reproduction, only a single parent cell reproduces and the new cells are genetically ______ to each other and the original cell.
Asexual, identical
______, not individual organisms, change or evolve over many generations
Species
______ ______ is the driving force for evolution
Natural Selection
Pushes better organisms to reproduce
According to natural selection, which individuals in a population are more likely to survive and be able to reproduce?
Organisms with favorable traits, “survival of the fittest”
A change in population due to the survival & reproduction of organisms with favorable traits is known as what?
Survival of the fittest
Define ecology:
Interaction of organisms with one another and with their environment
Three things that organisms need from their environment:
Nutrients, water, and gases
