Biology Keystone Practice Test

The cell is the fundamental unit of life that carries out all basic life processes. All living organisms are composed of one or more cells.

Mitochondria are responsible for producing the majority of a cell's energy in the form of ATP. Their role in energy production is critical for cellular function.

DNA is the molecule that stores and transmits genetic information in living organisms. It contains the instructions needed for growth, development, and reproduction.

Cellular respiration is the process by which eukaryotic cells convert glucose and oxygen into ATP, releasing energy for cellular work. It is a fundamental process that sustains life.

The cell membrane acts as a selective barrier that regulates the exchange of materials between the cell interior and its environment. This function is essential for maintaining cellular homeostasis.

Chlorophyll is the pigment that absorbs sunlight, which is then converted into chemical energy during photosynthesis. Its ability to capture light energy is vital for the production of glucose.

Mitosis is the process through which a cell divides to produce two identical daughter cells. This is critical for growth, tissue repair, and asexual reproduction in eukaryotic organisms.

Ribosomes are cellular organelles that translate messenger RNA into proteins. Protein synthesis is essential as proteins serve as structural components and catalysts in biological processes.

The law of segregation states that allele pairs separate during gamete formation, meaning each gamete receives only one allele of every gene. This is a cornerstone of Mendelian inheritance.

Chlorophyll is the key pigment in photosynthesis that absorbs light energy. Without it, plants would not be able to convert light energy into chemical energy effectively.

Osmosis is the specific type of diffusion that involves the movement of water across a selectively permeable membrane. It is a passive process driven by concentration differences.

A mutation is any alteration in the nucleotide sequence of DNA. This change can lead to variations in protein structure and function, influencing genetic diversity.

High biodiversity means there is a wide variety of species living together in an ecosystem. This diversity is crucial as it indicates a balanced and resilient environment.

Nitrogen fixation is the biological process that converts inert atmospheric nitrogen into ammonia, a form that can be absorbed by plants. This process is vital for incorporating nitrogen into the ecosystem.

Biotic factors refer to the living components of an ecosystem. Plants are living organisms that interact with other species, making them a prime example of a biotic factor.

The electron transport chain is crucial for creating a proton gradient across the mitochondrial membrane. This gradient powers ATP synthase, which produces ATP - the main energy currency of the cell.

A frameshift mutation results from the insertion or deletion of nucleotides that are not in multiples of three, shifting the gene's reading frame. This often results in a completely altered amino acid sequence and a nonfunctional protein.

Limiting factors such as food, water, and space restrict population growth by limiting resources. By doing so, they help maintain the ecological balance within a habitat.

Coevolution refers to the process where two or more species reciprocally affect each other's evolution. This can occur in predator-prey, host-parasite, or mutualistic relationships and shapes the adaptations of the interacting species.

Genetic drift is a random process that causes allele frequencies to fluctuate, particularly in small populations. This can lead to a reduction in genetic diversity and has significant evolutionary implications.