Biological Science: The Study of Life

Flashcards to review key vocabulary and concepts from the lecture on Biological Science.

Hypothesis

A testable and falsifiable statement that scientists use to make predictions about the natural world.

Natural Selection

A mechanism of evolution wherein individuals best adapted to their environment are more likely to survive and reproduce.

Genotype

The genetic makeup of an organism, represented by its allele pairs.

Phenotype

The observable physical or biochemical characteristics of an organism, as determined by both genetic makeup and environmental influences.

Mitosis

The process by which a cell divides its nucleus, generating genetically identical daughter cells.

Meiosis

The type of cell division that reduces the chromosome number by half, resulting in the formation of gametes.

Allele

An alternative form of a gene that may occur at a specific locus.

Dominant Trait

A trait that is expressed in the phenotype even when only one allele is present.

Recessive Trait

A trait that is masked in the phenotype by a dominant trait and requires two copies to be expressed.

Ecology

The scientific study of interactions among organisms and between organisms and their environment.

Biotic Factors

Living components of an environment that affect organisms, including other organisms.

Abiotic Factors

Non-living chemical and physical parts of the environment that affect living organisms.

Cell Transport

The process by which substances move into and out of cells, maintaining homeostasis.

Active Transport

The movement of substances across a cell membrane against their concentration gradient, requiring energy.

Photosynthesis

The process by which green plants use sunlight to synthesize foods with the help of chlorophyll.

Cell Respiration

The biochemical process in which cells convert glucose and oxygen into energy, producing carbon dioxide and water.

Genetic Drift

Random changes in allele frequencies in a population, often having a significant effect in small populations.

Gene Flow

The transfer of genetic material between populations, often as a result of migration.

Pedigree

A diagram that shows the occurrence and appearance of phenotypes of a genetic trait from one generation to the next.

Gene Expression

The process through which the information encoded in a gene is used to direct the synthesis of a specific protein.

Mutation

A change in the DNA sequence that can lead to variation in traits and may drive evolution.

Eukaryotic Cell

A complex cell characterized by membrane-bound organelles, including a nucleus.

Prokaryotic Cell

A simple cell lacking membrane-bound organelles, with genetic material not contained within a nucleus.

Define biochemistry.

Biochemistry is the branch of science that explores the chemical processes within and related to living organisms.

What are enzymes?

Enzymes are biological catalysts that speed up chemical reactions in cells without being consumed in the process.

What role do nucleotides play in biochemistry?

Nucleotides are the building blocks of nucleic acids like DNA and RNA, essential for storing and transmitting genetic information.

What is metabolism?

What is gene expression?

Gene expression is the process by which information from a gene is used to synthesize functional gene products such as proteins.

What is the role of RNA in protein synthesis?

RNA, particularly messenger RNA (mRNA), carries the genetic information from DNA to the ribosome, where proteins are synthesized.

Describe the process of transcription.

Transcription is the process in which the DNA sequence of a gene is copied into messenger RNA (mRNA).

What happens during translation?

Translation is the process where ribosomes read the sequence of mRNA to synthesize a polypeptide chain, forming a protein.

What is natural selection?

Natural selection is the process by which organisms better adapted to their environment tend to survive and produce more offspring.

What are adaptations?

Adaptations are characteristics or traits that enhance an organism's ability to survive and reproduce in its environment.

What is survival of the fittest?

Survival of the fittest refers to the concept that individuals best suited to their environment are more likely to survive and reproduce.

How does variation contribute to natural selection?

Variation among individuals in a population provides the raw material for natural selection, as some traits may confer a survival advantage

What is the function of enzymes?

Enzymes facilitate biochemical reactions by lowering the activation energy required for the reaction to occur.

What is a substrate in enzyme activity?

A substrate is the reactant molecule upon which an enzyme acts during a chemical reaction.

What factors affect enzyme activity?

Factors such as temperature, pH, and substrate concentration can influence the rate of enzyme-catalyzed reactions.

What is enzyme specificity?

Enzyme specificity refers to the tendency of an enzyme to catalyze a specific reaction for a specific substrate.

What are coenzymes?

Coenzymes are organic molecules that assist enzymes in their function, often by carrying chemical groups between enzymes.

What is the cell cycle?

The cell cycle is the series of phases that a cell goes through to grow and divide, including interphase and mitotic phase.

Describe the stages of interphase.

Interphase consists of three stages: G1 (cell growth), S (DNA synthesis), and G2 (preparation for mitosis).

What occurs during DNA replication?

DNA replication is the process of copying the DNA molecule, resulting in two identical DNA strands for cell division.

What is mitosis?

Mitosis is the process of cell division that results in two daughter cells, each with the same number of chromosomes as the parent cell.

What is the significance of the S phase in the cell cycle?

The S phase is critical because it is when the cell's DNA is replicated, ensuring that each daughter cell receives an accurate copy of the genome.

What enzymes are involved in DNA replication?

Key enzymes include DNA helicase (unwinds the DNA), DNA polymerase (synthesizes new DNA strands), and DNA ligase (joins Okazaki fragments).