Studying Life Flashcards
What does an organism need to be capable of doing to be considered alive?
Metabolism, reproduction and evolution
What is metabolism?
It’s the total chemical activity in a cell/metabolism.
Meaning of “anabolism”:
Building
Meaning of “catabolism”:
Breaking
What is the role of genes in the chemical reactions that compose the metabolism?
They provide control and coordination.
Definition of Homeostasis:
Homo: same
Stasis: spot
“Same spot”, cell/organism does the necessary chemical reactions to come back to a stable internal condition.
What is reproduction?
A process in which a cell/organism makes a new individual.
How are variations a major characteristic of life?
- The combination of reproduction and errors in the duplication of genetic information = EVOLUTION (biological)
- Variations in the environment = Diversification of life
- Enables cell/organism to adapt in different environments and have different life styles.
Definition of adaptation:
Internet or external changes that allow a cell/organism to adapt to a certain environment.
Advantages of sexual reproduction:
1.Organisms exchange genetic information=Offspings genetically variable
2.having genetically different offsprings= more chances in surviving in changing environment
Why are asexuel cell/organism at a disadvantage?
-They can only make a clone of themselves. This means that if that cell/organism is not able to survive in a certain environment, its offsprings won’t be able to survive either.
They can’t adapt.
How did life first arose?
It came from nonliving molecules that interacted with each other and formed the first molecule that made a copy of itself (nucleic acids/DNA)
What created the cellular membrane?
Lipids because they are hydrophobic. When reacting with water, they close onto themselves. So they accidently closed onto some DNA.
What was the name of the first cell?
Prokaryotic cell
Name a particular characteristic of the prokaryotic cell?
It has no nucleus.
Where did the prokaryotic cells live, and why did they live there ?
In the water, which protected them from the UV light (makes cell vibrate, which can break bonds) and infrared radiation (heat)
What did the prokaryotic cells develop into?
Cyanobacteria
What special ability does cyanobacteria have, and what is the result of this ability?
They do photosynthesis, and a by-product of this is O2 gas, which allowed aerobic metabolism (cellular respiration)
Apart from aerobic metabolism(cellular respiration), what else did the production of O2 bring?
It created ozone.
What was the impact of an ozone barrier on Earth? Explain the property of ozone and then answer the question.
Property of ozone:
- Prevents excess UV light from the sun from reaching Earth
This protection against UV light shielded enough that some organisms moved to land
What is the second evolution of prokaryotic cells?
Eukaryotic cells
What mainly differentiates prokaryotic and eukaryotic cells?
Eukaryotic cells have a nucleus, and the prokaryotic cells don’t
How did the prokaryotic cells evolve to be eukaryotic cells?
Some prokaryotic cells were big enough to engulf and digest smaller ones. But, some prokaryotic cells survived within the bigger prokaryotic cells, which created the first eukaryotic cells.
What are the advantages for the bigger prokaryotic cells and the smaller prokaryotic cells when merged?
- The bigger prokaryotic cell protects the smaller one
- The smaller prokaryotic cell gives energy to the bigger one
What are the 3 major domains of the provisional tree of life?
Bacteria, Archaea and Eukarya
Name the parts of a scientific name?
Genus (first name): Refers to a group of species that have a recent ancestor
Specific epithet (second name): identifies a specific species within the genus.
What are the five parts of the scientific method?
- Making observations
- Asking questions
- Forming hypotheses (tentative answer to question)
- Making predictions based on these hypotheses (ex. if… then…)
- Testing the predictions by conducting experiments
What is an independent variable?
The variable being manipulated. The “x” value. (What fo I change?)
What is a dependant variable?
The response that is measured. The “y” value. “y” is a function of “x”. (What do I observe?)
What are controlled variables?
One or more variables that are held constant in both the experimental and control groups
What is a positive control?
It’s when you know how a certain substance will react to the experiment and it can be used to compare with the other results
What is negative control?
It is when you know a substance in the experiment will not react at all.
