Key Concepts in Biology and Human Systems

Cellular Organization

All living things are made up of cells.

Metabolism

Living things use energy to carry out life processes.

Homeostasis

Living things maintain a stable internal environment.

Growth and Development

Living things grow and develop over time.

Reproduction

Living things produce offspring.

Response to Stimuli

Living things can respond to their environment.

Heredity

Living things pass on genetic information to their offspring.

Evolution

Living things change over time through evolution.

Prokaryotic Cells

Simple cells lacking a nucleus and membrane-bound organelles.

Eukaryotic Cells

Complex cells with a nucleus and membrane-bound organelles.

Plant Cell

Cell type that has a cell wall, chloroplasts, and a large central vacuole.

Animal Cell

Cell type that lacks a cell wall and chloroplasts, and has small or absent central vacuoles.

Nucleus

Control center of the cell.

Mitochondria

Powerhouse of the cell, produces ATP.

Ribosomes

Sites of protein synthesis.

Endoplasmic Reticulum (ER)

Smooth ER synthesizes lipids, rough ER modifies proteins.

Golgi Apparatus

Processes and packages proteins and lipids.

Lysosomes

Digest cellular waste.

Cytoskeleton

Provides structural support and aids in cell movement.

Centrioles

Involved in cell division.

Chloroplasts

Site of photosynthesis in plant cells.

Cell Wall

Provides structural support in plant cells.

Central Vacuole

Stores water and nutrients in plant cells.

Hydrolysis

Breaking down molecules by adding water.

Dehydration Synthesis

Building up molecules by removing water.

Carbohydrates

Energy source and structural support (e.g., glucose, starch, cellulose).

Lipids

Energy storage, insulation, and cell membrane components (e.g., triglycerides, phospholipids, cholesterol).

Proteins

Structural support, enzymes, hormones, and transport (e.g., amino acids).

Nucleic Acids

Store and transmit genetic information (e.g., DNA, RNA).

Alimentary Canal

Mouth, esophagus, stomach, small intestine, large intestine, rectum, anus.

Accessory Organs

Salivary glands, liver, gallbladder, pancreas.

Digestion

Breaks down food into nutrients.

Absorption

Nutrients are absorbed into the bloodstream.

Cellular Respiration

Cells use oxygen to convert nutrients into energy.

Aerobic Respiration

Requires oxygen, produces more ATP.

Anaerobic Respiration (Fermentation)

Does not require oxygen, produces less ATP.

Chemical Level

Atoms and molecules.

Cellular Level

Cells.

Tissue Level

Groups of cells with similar functions (epithelial, connective, muscle, nervous).

Organ Level

Groups of tissues working together (heart, lungs, kidneys).

Organ System Level

Groups of organs working together (digestive, respiratory, circulatory, etc.).

Organismal Level

The entire organism.

Insulin

Hormone that lowers blood glucose levels.

Glucagon

Hormone that raises blood glucose levels.

Diabetes

A disease characterized by high blood glucose levels.

Type 1 Diabetes

Autoimmune destruction of insulin-producing cells.

Type 2 Diabetes

Insulin resistance or insufficient insulin production.

Gestational Diabetes

Temporary diabetes during pregnancy.

Lungs

The primary organs of respiration, where oxygen is absorbed and carbon dioxide is released.

Alveoli

Tiny air sacs within the lungs where gas exchange occurs.

Heart

Pumps blood through the circulatory system.

Blood Vessels

Arteries carry blood away from the heart, veins carry blood towards the heart, and capillaries connect arteries and veins for gas and nutrient exchange.

Heart Disease

Conditions affecting the heart, such as heart attack, stroke, and heart failure.

Vascular Disease

Conditions affecting blood vessels, such as atherosclerosis and hypertension.

Cholesterol

A type of lipid found in cell membranes.

LDL (Low-Density Lipoprotein)

"Bad" cholesterol, linked to heart disease.

HDL (High-Density Lipoprotein)

"Good" cholesterol, helps remove LDL from the bloodstream.

Saturated Fats

Solid at room temperature, linked to heart disease.

Unsaturated Fats

Liquid at room temperature, generally considered healthier.

Reasons for Cell Division

Growth, repair, and reproduction.

Sexual Reproduction

Involves the fusion of gametes (sperm and egg) to produce offspring with genetic variation.

Asexual Reproduction

Involves a single parent and produces genetically identical offspring.

Chromosomes

Thread-like structures made of DNA, carrying genetic information.

Cell Cycle

Includes interphase, mitosis, and cytokinesis.

Cancer

Uncontrolled cell growth caused by mutations in genes that regulate cell division.

Natural Selection

The process by which organisms with advantageous traits are more likely to survive and reproduce.

Artificial Selection

Selective breeding of organisms by humans.

Bacterial Genetic Transfer

Includes conjugation, transformation, and transduction.

Antibiotic Resistance

Bacteria can develop resistance to antibiotics through genetic mutations.

Viruses

Non-living particles that can infect cells and replicate.

Lytic Cycle

Virus replicates immediately, killing the host cell.

Lysogenic Cycle

Virus integrates its genetic material into the host cell's DNA, remaining dormant.

Defensive Elements

Physical barriers, innate immune system, adaptive immune system.

Physical Barriers

Skin, mucous membranes, cilia.

Inflammatory Response

A localized response to infection or injury.

Lymphatic System

Filters lymph fluid and transports immune cells.

Non-specific Immunity

General defenses against pathogens.

Specific Immunity

Targeted response to specific pathogens.

Antigen

A foreign substance that triggers an immune response.

B Cells

Produce antibodies to fight infection.

T Cells

Attack infected cells and regulate the immune response.

B Cells and T Cells

B cells produce antibodies, T cells attack infected cells.

Vaccines

Weakened or inactivated pathogens that stimulate the immune system.

Double-Blind Studies

Neither the participants nor the researchers know who is receiving the treatment or placebo.

Coronaviruses

A large family of viruses that can cause respiratory infections.

mRNA Vaccines (Moderna, Pfizer)

Introduce mRNA to produce viral spike protein, triggering an immune response.

Viral Vector Vaccine (Johnson & Johnson)

Uses a modified virus to deliver viral genetic material.

Meiosis

Cell division that produces gametes.

Meiosis I

Homologous chromosomes separate.

Meiosis II

Sister chromatids separate.

Genetic Variation

Independent assortment, crossing over, random fertilization.

Mitosis vs. Meiosis

Mitosis produces two identical diploid cells, meiosis produces four genetically different haploid cells.

Nondisjunction

Failure of chromosomes to separate properly during meiosis.

Reproductive System

Male and female reproductive organs produce gametes and facilitate fertilization.

Human Development

Fertilization, zygote, embryo, fetus, birth.

Infertility

Various factors can contribute to infertility, including hormonal imbalances, blocked fallopian tubes, and low sperm count.

Assisted Reproduction

Techniques to help couples conceive, such as artificial insemination, in vitro fertilization, and intracytoplasmic sperm injection.

Eukaryotic Nucleus

Contains chromosomes and nucleolus.

Mendelian Inheritance

Simple inheritance patterns governed by dominant and recessive alleles.

Non-Mendelian Inheritance

Complex inheritance patterns, such as incomplete dominance, codominance, and polygenic traits.