Glossary
Adaptations
Beneficial traits that enhance an organism's survival and reproduction in a specific environment.
Example:
The thick fur of a polar bear is a crucial adaptation that helps it survive in frigid Arctic temperatures.
Chlorophyll
A pigment found in plants and algae that absorbs light energy for photosynthesis, with different types absorbing various wavelengths.
Example:
Deep-sea algae often possess unique forms of chlorophyll that can absorb the dim blue-green light that penetrates to those depths, enabling photosynthesis where other plants cannot.
Evolution
The change in the genetic makeup of a population over successive generations, driven by mechanisms like natural selection.
Example:
The development of antibiotic resistance in bacteria over decades is a clear demonstration of evolution occurring within a population.
Fitness
An organism's ability to survive and reproduce successfully in its environment.
Example:
A cheetah that is faster and more agile than others in its pride will likely catch more prey, leading to better survival and more offspring, demonstrating high fitness.
Hemoglobin
A protein in red blood cells responsible for oxygen transport, with different types exhibiting varied oxygen-binding properties.
Example:
High-altitude dwellers often have a type of hemoglobin that binds oxygen more efficiently at lower atmospheric pressures, allowing them to thrive in oxygen-scarce environments.
Molecular variation
Differences at the molecular level, such as in the types or sequences of molecules, that allow organisms to respond to different environments.
Example:
The presence of different enzymes in bacteria that can break down various sugars is an example of molecular variation allowing them to utilize diverse food sources.
Natural Selection
A mechanism of evolution where individuals with advantageous traits are more likely to survive and reproduce, passing those traits to their offspring.
Example:
The increasing resistance of bacteria to antibiotics is a classic example of natural selection in action, as resistant strains survive and multiply.
Phospholipids
A type of lipid that forms cell membranes, with variations in their fatty acid tails affecting membrane fluidity and melting points.
Example:
Fish living in extremely cold ocean waters have a higher proportion of unsaturated phospholipids in their cell membranes, which helps keep the membranes fluid and functional at low temperatures.
Variation
Differences in DNA among individuals within a population, providing the raw material for natural selection.
Example:
The diverse shell patterns and colors among snails in a garden illustrate genetic variation within the population.