Biology Practice Final Vocabulary

Prokaryotic Cells: These are defined as cells that do not contain a nucleus or any other membrane-bound organelles. They are structurally simpler than eukaryotic cells.
Eukaryotic Cells: These are cells containing a nucleus and other membrane-bound organelles. This category includes both plant and animal cells.
Cellular Differences (Plant vs. Animal): - Plant cells possess a cell wall, which provides structure and support. Animal cells do not have a cell wall. - Cytoplasm, mitochondria, and ribosomes are found in both animal and plant cells.
Organelles and Their Functions: - Mitochondria: Responsible for producing energy (ATP) within the cell. They regulate energy by converting energy found in nutrients into a usable form for the cell. This is the primary site of cellular respiration. - Cell Membrane: This structure controls what enters and leaves a cell. Its main purpose is selective permeability, ensuring only specific molecules can pass through. - Nuclear Membrane: Specifically controls the movement of materials into and out of the nucleus. - Ribosomes: The site of protein synthesis. - Vacuoles: Used for storage; specific types like the contractile vacuole in protists help eliminate excess liquid by "pumping," a process that requires energy in the form of $ATP$ to prevent the cell from bursting. - Chloroplasts: Organelles found in plants that absorb and convert energy from the sun (photosynthesis).

Life is organized in a hierarchy from simplest to most complex: - $Atoms \rightarrow Cells \rightarrow Tissues \rightarrow Organs \rightarrow Organ Systems \rightarrow Organisms$
A cell is the smallest and simplest basic unit of life.

There are four major classes of macromolecules essential for life:

Carbohydrates: - Composed of the elements Carbon ( $C$ ), Hydrogen ( $H$ ), and Oxygen ( $O$ ). - The chemical formula for glucose, a common carbohydrate, is $C_{6}H_{12}O_{6}$ . - Function: Used as the primary source of short-term energy.
Lipids: - Function: Their main function is to store energy (long-term storage).
Proteins: - Building Blocks: Composed of monomers called amino acids. - Enzymes: Specialized proteins that increase the rate of chemical reactions inside cells. The specific shape of an enzyme determines its function, as enzymes are specific to a particular substrate.
Nucleic Acids: - Components: Made of nucleotides, which consist of three parts: a sugar, a phosphate group, and a nitrogen base. - Function: To store and transmit genetic information. They work together to form DNA and RNA.

ATP (Adenosine Triphosphate): The energy currency of the cell. - Storage: Energy is stored when a phosphate group is added to a molecule to create $ATP$ . - Source: The source of energy for active cellular processes (like pumping a contractile vacuole) is $ATP$ .
Photosynthesis vs. Cellular Respiration: - There is a direct relationship between the two processes: The products of photosynthesis (glucose and oxygen) serve as the reactants in cellular respiration to provide chemical energy for the cell.
Active Transport: Process of moving materials into or out of a cell that requires the expenditure of energy ( $ATP$ ). This is distinct from passive movement.
Osmosis and Diffusion: - Osmosis: The movement of water across a membrane. During osmosis, water moves from an area of high concentration to an area of low concentration without the use of energy. - Tonicity Effects: - Hypertonic (Salty) Solutions: If an animal cell or a freshwater plant cell is placed in a hypertonic/saltwater solution, the cell will shrink because water moves out of the cell toward the higher solute concentration.

DNA (Deoxyribonucleic Acid): - Structure: Double-stranded. - Sugar: Contains deoxyribose. - Nitrogen Bases: Adenine, Thymine, Guanine, Cytosine.
RNA (Ribonucleic Acid): - Structure: Single-stranded. - Sugar: Contains ribose. - Nitrogen Bases: In RNA, Uracil pairs with Adenine. Thymine is not present.
Messenger RNA (mRNA): The specific type of RNA that carries the genetic code from the DNA in the nucleus out to the ribosomes.
Transcription: The process of transcribing DNA into RNA. - Base Pairing Rules (DNA to RNA): - $A \rightarrow U$ - $T \rightarrow A$ - $C \rightarrow G$ - $G \rightarrow C$ - Example 1: DNA sequence TAGGCA pairs with RNA sequence AUCCGU. - Example 2: DNA sequence TAG GGA CCT AAC transcribes to RNA AUC CCU GGA UUG.
Cell Cycle: Before a cell divides, DNA must replicate to ensure the proper division and distribution of chromosomes to daughter cells.

Genotype: Refers to the possible combinations of alleles in a gene (the genetic makeup).
Phenotype: Refers to the physical appearance of a trait (how an organism looks).
Allele Combinations: - Heterozygous: Carrying two different alleles (e.g., $Tt$ or $Gg$ ). - Homozygous Dominant: Carrying two dominant alleles (e.g., $TT$ ). - Homozygous Recessive: Carrying two recessive alleles (e.g., $tt$ ).
Predicting Inheritance (Probability): - In a cross between two heterozygous organisms ( $Tt \times Tt$ ): - Probability of homozygous dominant ( $TT$ ) offspring: $25\%$ - Probability of heterozygous ( $Tt$ ) offspring: $50\%$ - Probability of homozygous recessive ( $tt$ ) offspring: $25\%$ - Dominance Example: If $G$ is the allele for gray and $g$ is the allele for blue, an organism with the genotype $Gg$ will appear Gray due to the dominant allele.
Blood Typing: - Blood type is determined by antigens found on the surface of red blood cells. - Universal Donor: Blood type $O$ . - Universal Recipient: Blood type $AB$ .

Evolution: The gradual change in a species over time.
Natural Selection: The process by which individuals better suited to their environment survive and produce offspring with more favorable genes. This is often summarized as "survival of the fit enough."
Variation: Differences within a population. Importantly, variation is NOT goal-oriented.
Evolutionary Units: Populations evolve over time; individuals DO NOT evolve.
Adaptations: Inherited traits that help an organism survive. There are three types: 1. Behavioral: Responses or actions (e.g., migration). 2. Structural: Physical features (e.g., beak shape). 3. Physiological: Internal processes (e.g., venom production).
Natural Selection Types: - Directional Selection: Occurs when natural selection favors one extreme of a given trait.

Skeletal Muscles: Also known as voluntary muscles because they are under conscious control.
Digestive System: Responsible for breaking down food into smaller molecules and passing nutrients into the bloodstream.