Exam 1 Flashcards
What modern evidence is consistent with the hypothesis that mitochondria & chloroplasts arose through endosymbiosis?
- DNA structure & cell division of mitochondria & chloroplasts are similar to those in bacteria
- Mitochondria & chloroplasts transcribe and translate their own DNA
- Their ribosomes are more similar to bacterial ones and synthesize their own proteins
- Eukaryotic cells cannot make more mitochondria or chloroplasts
What caused Snowball Earth to become warmer and melt?
Volcanoes protruded through the ice, released greenhouse gases which in turn heated the earth
From which method do we know approximately what the Earth was like when it was formed?
analysis of meteorites
Ingredients for the origin of life include:
- Basic elements
- Basic organic compounds
- Complex biomolecule(s) capable of replication
- A membrane enclosure
Why are stromatolites important to our understanding of early life on Earth?
They provide evidence of ancient microbial life and early photosynthesis.
What were the two first essential elements required to form other common building elements for living organisms?
Hydrogen and helium
T & F: The Cambrian explosion was caused by impact on Earth of a large meteorite
False
The current leading hypothesis about the first system of inheritance in the earliest life forms involves:
self-replicating RNA molecules with ribozyme activity
In the context of astrobiology and the search for extraterrestrial life, Fermi’s Paradox raises intriguing questions. Which of the following best summarizes Fermi’s Paradox?
It questions why, given the vast number of potentially habitable planets, we have not yet observed signs of advanced extraterrestrial civilizations.
What did the early experiments (from the video in class) demonstrate about the role of light in photosynthesis?
Light is required for plants to produce oxygen.
Which of the following best describes why emergent properties are difficult to predict?
They result from interactions between components, making it hard to foresee the overall outcome.
T & F: Viruses do not evolve.
False
T &F: Anaerobic bacteria existed earlier than aerobic bacteria
True
Where are Archaea found?
Often found in extreme habitats such as low acidity and high temperature
Zircons are important because:
their appearance in the geological record is the earliest evidence of liquid water on Earth
T &F: The simplest known bacteria evolved from a virus.
False
During the Hadean Eon, ~4 BYA, which of these was likely to emerge?
Protocells
A nucleus of a cell:
has its own membrane
In addition to light energy from the sun, what two substances are needed in order for photosynthesis to take place?
carbon dioxide and water
T & F: The first fossil evidence dates from about 1 billion years coinciding with the appearance of the first eukaryotic cells.
False
The Cambrian Period was characterized by unprecedented proliferation of species & phyla including an explosion
of animal diversity. Identify the one FALSE statement below.
The Cambrian Period occurred during the late Hadean eon.
What compounds and conditions did Stanley Miller use to perform his 1953 experiment to simulate the atmosphere of early Earth to test the hypothesis of abiotic synthesis of organic molecules?
water vapor, H2 (hydrogen gas), CH4 (methane), NH3 (ammonia), spark for lightening
Banded iron formations arise from
O2 reacting with iron, causing it to rust out of the oceans about 2.4 BYA
Which scientific evidence allows us to reconstruct the origins of Earth and evolution of life?
Analysis of rocks: meteorites, volcanic rocks/sediment, stromatolites, sedimentary rocks
The Stanley Miller experiments
The discovery of RNA with catalytic activity, ribozymes
Technological advances in modern telescopes to observe and study the birth of a solar system and planets
