Exam 2 Study Guide Flashcards
(54 cards)
What is the estimate of Earth’s age?
4.6 billion years ago
Which is more inclusive when describing the time since earth formed, an Era or a Period?
Era
Which Eon contained the largest biodiversity of life?
Phanerozoic Era
What are four components believed to have made up the majority of early earth’s atmosphere?
- Proteins
- Nucleic Acid
- Carbohydrates
- Lipids
What most important component did earth’s early atmosphere lack?
The evolution of cells
Whose experiment in 1953 demonstrated that indeed, the building blocks of life could have arisen from the components available on early earth?
The Miller-Urey experiment.
What were they building blocks of the Miller-Urey experiment?
Methane, ammonia, hydrogen, and water.
They created organic compounds including amino acids.
Which component likely drove the great temperatures of early earth?
The rocky mantle melted, causing atmospheric temperatures of > 2000 C
How old are the oldest microfossils found on earth? What do they resemble?
3.5 billion years old.
Resembles prokaryotes.
If you had a fossil believed to be over 3 billion years old, would it be better to use carbon or potassium isotopes to measure its age? Why?
Potassium isotopes, have a 1.25 billion year half-life while carbon isotopes have a 5700 year half-life.
How do weathering rocks result in decreased atmospheric CO2. Where does the carbon go?
The CO2 in the atmosphere combined with H2O to form carbonic acid.
Then the carbonic acid reacts with rocks.
Then the carbon is carried by rivers.
Precipitates when calcium and bicarbonate form calcium carbonate.
Earths temperature is decreased as CO2 decreases.
Did plants contribute to glaciations?
Growing evidence suggests that plants contributed to two glaciations.
Plant colonization was followed by gradual cooling and glaciations 488-444 mya
Vascular plant diversification was concurrent with the second glaciation 400-360 mya; phosphorous was released through weathering.
What are the 3 domains of life on earth?
Life eventually evolved into three monophyletic domains.
- Eubacteria
- Archaea
- Eukaryotes
Each of these is a clade.
What are the six supergroups of domain Eukaryote?
- Chromalveolates
- Rhizaria
- Archaeplastida
- Excavata
- Amoeboza
- Opisthokonta
What characteristic primarily differentiates prokaryotes from more complex eukaryotes?
Prokaryotes lack compartmentalization. Eukaryotes developed extensive endomembrane system with their compartmentalization.
What is ecology?
The study of how organisms relate to one another and to their environments.
What are the 4 primary elements of the environment?
Temperature: specific range
Water: required, rainfall dictates life
Sunlight: required by all? For photosynthesis
Soil: can limit terrestrial growth
What is the difference between a short and long term response? Give a physiological response that might apply to both.
Short term response: from a few minutes to an individual’s lifetime; physiological response is sweating
Long term response: natural selection can operate to make a population better adapted to the environment;
How are Allen’s and Bergmann’s rules related?
Allen’s rule of reduced surface area states that mammals from colder climates have shorter ears and limbs.
Bregmann’s rule states that larger species are found in colder environments while species of smaller size are found in warmer environments.
What is a population?
A group of individuals of a species in one place
What are the 3 characteristics of population ecology?
- Population range: area throughout which a population occurs
- Pattern of spacing of individuals
- How population changes in size through time
Describe source-sink metapopulations.
Some areas are suitable for a long-term habitat while others are not. Populations in better areas (source) bolster the population in poorer areas (sink).
Why don’t males generally affect population dynamics?
Number of births relates to the number of females. Females give birth and are therefore necessary for birth.
House flies progress through a complete life cycle in about 14 days and produce 700 eggs in their lifetime. Which would apply to fecundity and which to generation time?
Fecundity is the number of offspring produced in a standard time “per year”
Generation time is the average interval between egg to egg
