Comprehensive Guide to Earth Science and Evolution
Continental Drift Theory
Paleolithic evidence: Identical fossils of land-based organisms were found in continents situated far apart.
Geological evidence: Continents fit together along their coastlines and continental shelves. Rocks of the same age and type appear on each side of the line where they were joined.
Paleoclimatic evidence: Continents situated in the South Pole of Pangea have glacial moraines from the same age.
Wilson Cycle
Two cyclical processes of rifting and reuniting of supercontinents
Read MoreMutations and Genetic Variation
Mutations
Mutations alter DNA sequences and are the basis of alleles, the source of genetic variation in populations (fuel for evolutionary change), the cause of genetic diseases and disorders, and useful tools for understanding biological processes.
Mutations occur in somatic and germ cells, but only germline mutations are passed down to offspring.
Types of Mutations Based on Protein Function
- Gain-of-Function (GOF) Mutations: Increase gene/protein activity or produce new activity. Often dominant. Example:
Understanding the Cell Cycle and Mitosis
The Cell Cycle
The first stage of cell division is interphase, which is divided into three phases: G1, S, and G2. During interphase:
- DNA is present as uncondensed chromatin (not visible under a microscope).
- DNA is contained within a clearly defined nucleus.
- Centrosomes and other organelles have been duplicated.
- The cell is enlarged in preparation for division.
Phases of Interphase
- G1 (Gap phase 1): The cell grows larger.
- S (Synthesis): The genome is replicated.
- G2 (Gap phase 2): The second growth phase,
Comprehensive Guide to Earth Science and Evolution
Continental Drift Theory
Paleontological Evidence: Identical fossils of land-based organisms were found in continents situated far apart.
Geological Evidence: Continents fit together along their coastlines and continental shelves. Rocks of the same age and type appear on each side of the line where they were joined.
Paleoclimatic Evidence: Continents situated in the South Pole of Pangea have glacial moraines from the same age.
Wilson Cycle
Two cyclical processes of rifting and reuniting of supercontinents
Read MoreFrom DNA to Protein: A Deep Dive into Protein Synthesis
The Polymerase Chain Reaction (PCR)
The polymerase chain reaction (PCR) is an artificial method of replicating DNA under laboratory conditions. The process involves the following steps:
- Denaturation: The DNA sample is heated (~90ºC) to separate the two strands.
- Annealing: The sample is cooled (~55ºC) to allow primers to anneal. Primers designate the specific sequence to be copied.
- Elongation: The sample is heated to the optimal temperature for a heat-tolerant polymerase (Taq) to function (~75ºC).
Cellular Respiration and Photosynthesis: The Energy Cycles of Life
Why ATP is Useful to Cells
ATP can easily release and store energy by breaking and re-forming the bonds between its phosphate groups.
Energy
The ability to do work
ATP Stands for…
Adenosine triphosphate
ATP Consists of…
Adenine, a 5-carbon sugar called ribose, and three
phosphate groups
ADP Stands for
Adenosine diphosphate
Difference Between ATP and ADP
ADP has two phosphate groups, while ATP has three phosphate groups.
(ATP, ADP) Can Contain More Energy
ATP
Cells Release Energy by…
Breaking the bonds between
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