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What is Biology?

Biology is the scientific study of life. It examines the structure, function, growth, origin, evolution, and distribution of living organisms.

What are the characteristics of life?

Living organisms typically share several key characteristics:

• Organization (cells, tissues, organs, systems)
• Metabolism (energy processing)
• Reproduction
• Growth and Development
• Response to stimuli
• Adaptation and Evolution
• Homeostasis (maintaining internal balance)

What is the basic unit of life?

The cell is the basic unit of life. It is the smallest structural and functional unit of an organism.

What are the two main types of cells?

The two main types of cells are:

• Prokaryotic cells (lacking a nucleus and other complex organelles)
• Eukaryotic cells (containing a nucleus and other membrane-bound organelles)

What is Biology?

Biology is the scientific study of life. It examines the structure, function, growth, origin, evolution, and distribution of living organisms.

What are the characteristics of life?

Living organisms typically share several key characteristics:

• Organization (cells, tissues, organs, systems)
• Metabolism (energy processing)
• Reproduction
• Growth and Development
• Response to stimuli
• Adaptation and Evolution
• Homeostasis (maintaining internal balance)

What is the basic unit of life?

The cell is the basic unit of life. It is the smallest structural and functional unit of an organism.

What are the two main types of cells?

The two main types of cells are:

• Prokaryotic cells (lacking a nucleus and other complex organelles)
• Eukaryotic cells (containing a nucleus and other membrane-bound organelles)

What is DNA?

DNA (deoxyribonucleic acid) is the hereditary material in humans and almost all other organisms. It contains the genetic instructions for the development, functioning, growth and reproduction of organisms.

What is a gene?

A gene is a unit of heredity that is transferred from a parent to offspring and is held to determine some characteristic of the offspring. Genes are made up of DNA.

What is evolution?

Evolution is the change in the heritable characteristics of biological populations over successive generations. These characteristics are genes that are passed on from parent to offspring.

What is natural selection?

Natural selection is the process by which organisms better adapted to their environment tend to survive and reproduce more successfully. It is a key mechanism of evolution.

What are the levels of biological organization?

The levels of biological organization include:

• Molecules
• Cells
• Tissues
• Organs
• Organ Systems
• Organisms
• Populations
• Communities
• Ecosystems
• Biosphere

What is homeostasis?

Homeostasis is the ability of an organism to maintain a stable internal environment despite changes in external conditions.

What is metabolism?

Metabolism is the set of chemical processes that occur in living organisms to maintain life. These processes include catabolism (breaking down molecules) and anabolism (building molecules).

What is ecology?

Ecology is the study of the interactions between organisms and their environment.

What is a biome?

A biome is a large geographic area characterized by specific climate conditions, animal populations, and plant species.

Photosynthesis is the process by which plants and other organisms convert

What is heredity?

The passing on of traits from parents to offspring. Traits are determined by genes.

What is an allele?

A version of a gene. For example, for the gene that determines pea plant color, there can be a green allele and a yellow allele.

What does homozygous mean?

Having two identical alleles for a particular gene.

What does heterozygous mean?

Having two different alleles for a particular gene.

What is a genotype?

The genetic makeup of an organism (e.g., GG, Gg, gg).

What is a phenotype?

The observable characteristics of an organism (e.g., green pea plant, yellow pea plant).

What is a Punnett square?

A diagram used to predict the genotypes and phenotypes of offspring from a genetic cross.

What is a dominant trait?

A trait that masks the expression of another trait when present in a heterozygous individual.

What is a recessive trait?

A trait that is masked by a dominant trait when present in a heterozygous individual.

What is a pedigree?

A chart that shows the inheritance of traits in a family over several generations.

What is a mutation?

A change in the DNA sequence.

What are the four nitrogenous bases in DNA?

Adenine, Thymine, Guanine, Cytosine

What is cellular respiration?

The process by which cells convert glucose into energy in the form of ATP.

What is the balanced equation for cellular respiration?

C6H{12}O6 + 6O2 \rightarrow 6CO2 + 6H2O + \text{ATP}.

What are the three main stages of cellular respiration?

Glycolysis, Krebs Cycle, Electron Transport Chain

What is glycolysis?

The breakdown of glucose into pyruvate, occurring in the cytoplasm.

What is the Krebs Cycle (Citric Acid Cycle)?

A series of chemical reactions that extract energy from pyruvate, producing ATP, NADH, and FADH2; occurs in the mitochondrial matrix.

What is the electron transport chain (ETC)?

It is a the process that occurs in the inner mitochondrial membrane, using electrons from NADH and FADH2 to produce a proton gradient that drives ATP synthesis.

What is ATP synthase?

The enzyme that synthesizes ATP using the proton gradient generated by the electron transport chain.

What is the total ATP yield in cellular respiration?

C6H{12}O6 + 6O2 \rightarrow 6CO2 + 6H2O + \text{energy}. The net ATP production is 36-38 ATP molecules per glucose molecule.

What is fermentation?

An anaerobic process that regenerates NAD^+, allowing glycolysis to continue in the absence of oxygen.

What are the two main types of fermentation?

Lactic acid fermentation (occurs in animal muscle cells and some bacteria) and alcoholic fermentation (occurs in yeast).

What is cell growth?

The irreversible increase in the size of a cell or the number of cells.

What are the three main processes involved in cell growth?

Cell division, cell enlargement, and differentiation.

What is cell division?

The process where one cell divides into two identical daughter cells.

What are the purposes of cell division?

Asexual reproduction, growth, and repair.

What is the cell cycle?

The cell cycle is the series of events that take place in a cell leading to its division and duplication of its DNA (DNA replication) to produce two daughter cells.

What are the two main phases of the cell cycle?

Interphase (G1, S, G2 phases) and Mitotic phase (Mitosis and Cytokinesis).

What happens during the G1 phase?

The cell grows and performs its normal functions.

What happens during the S phase?

DNA replication occurs.

What happens during the G2 phase?

The cell prepares for mitosis by synthesizing necessary proteins and organelles.

What are the four main stages of mitosis?

Prophase, Metaphase, Anaphase, and Telophase.

What is cell transport?

The transport of substances across the cell membrane.

What are the two main types of cell transport?

Passive transport and active transport.

What is passive transport?

Transport that does not require energy input; substances move down their concentration gradient.

What are the types of passive transport?

Diffusion, osmosis, and facilitated diffusion.

What is a hypertonic solution?

The movement of substances from an area of high concentration to an area of low concentration.

What is osmosis?

The diffusion of water across a selectively permeable membrane from an area of high water concentration to an area of low water concentration.

What is facilitated diffusion?

The movement of substances across the cell membrane with the help of transport proteins, without energy input.

What is active transport?

Transport that requires energy input (ATP); substances move against their concentration gradient.

What are the main types of active transport?

Sodium-potassium pump and endocytosis/exocytosis.

What is the sodium-potassium pump?

Active transport. A protein pump that moves sodium ions out of the cell and potassium ions into the cell, against their concentration gradients.

What is endocytosis?

The process by which cells take in substances by engulfing them in a vesicle.

What is exocytosis?

The process by which cells release substances by fusing a vesicle with the cell membrane.

What is ecology?

The study of the interactions between organisms and their environment.

What are biotic factors?

Living components of the environment.

What are abiotic factors?

Non-living components of the environment (e.g., temperature, light, water, nutrients).

What is an organism?

Individual organism.

What is a population?

A group of individuals of the same species living in the same area.

What is a community?

A group of different populations living and interacting in the same area.

What is an ecosystem?

The community of organisms in an area, along with the non-living components of the environment.

What is the biosphere?

The global ecosystem, encompassing all living organisms and their environments.

Autotrophs (producers) and heter