II. Life Science

Prokaryotes

Single-celled organisms with no nucleus (e.g., bacteria).

Eukaryotes

Organisms with cells that have a nucleus and membrane-bound organelles (e.g., animals, plants, fungi).

Nucleus

The control center of eukaryotic cells (i.e animal, plant, fungi etc.) containing DNA.

Mitochondria

Powerhouse of the cell; site of cellular respiration.

Cell Membrane

Protects the cell and regulates what enters/exits.

Cytoplasm

Jelly-like substance where cell processes occur.

Chloroplasts

Site of photosynthesis in plants; contain chlorophyll.

Cellular Respiration

Process by which cells convert glucose and oxygen into energy (ATP), carbon dioxide, and water.

Photosynthesis

Process by which plants use sunlight to synthesize foods from carbon dioxide and water.

Circulatory System

Transports blood, nutrients, and oxygen throughout the body.

Respiratory System

Facilitates gas exchange (O2 in, CO2 out) through lungs.

Digestive System

Breaks down food into nutrients that can be absorbed by the body.

Excretory System

Removes waste from the body, including kidneys, bladder, and urinary tract.

Nervous System

body’s control system that coordinates actions and transmits signals between different parts of the body.

Endocrine System

Regulates hormones and controls processes like growth, metabolism, and reproduction.

Immune System

Defends the body against pathogens (viruses, bacteria).

Sexual Reproduction

Involves two parents; produces genetically diverse offspring.

Asexual Reproduction

Involves one parent; offspring are genetically identical.

Mitosis

Cell division resulting in two identical daughter cells.

Meiosis

Cell division that produces four non-identical sex cells (gametes).

Double Helix

The shape of DNA, consisting of two strands coiled together.

Nitrogen Bases (A. T. C. G)

Adenine (A), Thymine (T), Cytosine (C), Guanine (G).

Sugar-Phosphate Backbone

The structural framework of DNA.

Dominant Traits

Traits expressed in the presence of one dominant allele.

Recessive Traits

Traits expressed only when both alleles are recessive.

Punnett Square

Tool to predict offspring genotypes and phenotypes.

Natural Selection

Concept proposed by Charles Darwin that organisms with favorable traits are more likely to reproduce.

Adaptation

A characteristic that improves an organism's ability to survive in its environment.

Mutation

A change in DNA that may lead to new traits.

Fossils

Preserved remains of ancient organisms; provide evidence of past life and evolutionary changes.

Kingdoms (B. P. F. P. A)

biological classification groups:

Bacteria (prokaryotes), Protists (eukaryotes), Fungi (decomposers), Plants (photosynthetic), Animals (heterotrophic),

Taxonomy (D. K. P. C. O. F. G. S)

Classification hierarchy:

Domain → Kingdom → Phylum → Class → Order → Family → Genus → Species.

Producers

Organisms that produce their own food (e.g., plants).

Consumers

Organisms that eat other organisms (primary, secondary, tertiary).

Decomposers

Organisms that break down dead matter (e.g., fungi, bacteria).

Mutualism

A symbiotic relationship where both organisms benefit.

Commensalism

A symbiotic relationship where one organism benefits and the other is unaffected.

Parasitism

A symbiotic relationship where one organism benefits at the expense of the other.

Carrying Capacity

The maximum number of individuals an environment can support.

Limiting Factors

Resources or conditions that limit the growth of a population (e.g., food, water, space).

Plant Life Cycle (S. G. G. R)

Stages: Seed → Germination → Growth → Reproduction.

Animal Life Cycle (E. L. P. A)

Stages of metamorphosis: Egg → Larva → Pupa → Adult.

Homeostasis

organisms maintain a stable internal environment despite external changes.

Amino Acid

Organic compounds that combine to form proteins; building blocks of proteins.

Cell Division

When a parent cell divides to form two or more daughter cells.

Genes

Segments of DNA that determine traits.

Gregor Mendel

Father of genetics; known for experiments with pea plants that established basic principles of heredity.

Law of Segregation

Mendel's law stating that each organism has two alleles for each trait, which segregate during gamete formation.

Law of Independent Assortment

Mendel's law stating that genes for different traits are inherited independently.

Regulation

The process of controlling or managing biological functions, such as homeostasis and gene expression.

Ectothermic

Cold-blooded Organisms that regulate their body temperature based on external environmental conditions.

Open Circulatory System

where blood flows freely within the body cavity, directly bathing organs.

Closed Circulatory System

where blood circulates within vessels, separated from the surrounding tissue.

Interdependence of Organisms

The reliance of different organisms on each other for survival, often seen in ecosystems.

Food/Energy Pyramid (P. PC. SC. TC)

A graphical representation of the flow of energy through an ecosystem.

Producers, Primary Consumers, Secondary Consumers, Tertiary Consumers

Symbiosis

A close relationship between two different species that live together, benefiting at least one organism.

Bacteria

Single-celled microorganisms that can be beneficial or harmful.

Virus

Microscopic infectious agents that can only reproduce within living host cells.

Animal Cells

Eukaryotic cells that make up animals, lacking a cell wall but containing organelles.

Plant Cells

Eukaryotic cells that make up plants; contain cell walls and chloroplasts.

Cell Reproduction

The process by which cells divide to create new cells.

Benefits of Sexual Reproduction over Asexual Reproduction

Sexual reproduction introduces genetic diversity; asexual reproduction creates identical offspring.

Trisomy

A genetic condition where an individual has three copies of a chromosome.

DNA

Deoxyribonucleic acid, the molecule that carries genetic information.

Change Over Time in Living Things

The process of evolution, where species gradually change over generations.

Evolution

The process through which species change over time through mechanisms like natural selection.

Behavior

The actions or reactions of an organism in response to its environment.

Endothermic

Organisms that regulate their body temperature internally.

Vertebrate

Animals with a backbone or spinal column.

Invertebrate

Animals without a backbone.

Unity of Life

The concept that all living organisms share certain characteristics.

Diversity of Life

The variety of living organisms resulting from evolutionary processes.

Classification

The scientific system of categorizing living organisms into groups.

Competition

When two or more organisms vie for the same resources.

Predation

An interaction where one organism hunts and consumes another.

Covalent Bond

A type of chemical bond where two atoms share electrons to form a stable molecule.

Genes & Heredity

Units of heredity passed from parent to offspring. Alleles are different forms of a gene, either dominant or recessive.

DNA replication

process of copying a DNA molecule to create two identical copies.

Interaction of Organisms

Ways in which organisms interact with each other and their environment.

Examples: Feeding relationships, symbiosis, competition

Metamorphosis

biological process in which an organism undergoes a significant transformation in its body structure during its life cycle

Gamets

Reproductive cells (sperm in males, egg/ovum in females) carry half the genetic material (haploid) of an organism.

Genotype

genetic makeup of an organism; the combination of alleles inherited from parents.

Phenotype

observable physical traits or characteristics of an organism, determined by its genotype and environmental factors.

Primary Consumers

Herbivores that eat producers (plants or algae).

• Example: Grasshoppers, deer

Secondary Consumers

Carnivores that eat primary consumers.

• Example: Frogs, small birds

Tertiary Consumers

Carnivores that eat secondary consumers.

• Example: Hawks, lions.