General Bio NLN

What is the smallest living functional and structural unit of life? How much water consists of it?

The cell. It makes up all living things and is ~60% water.

plasma (cell) membrane

semipermeable barrier that separates the inside of the cell from the interstitial fluid

Memory trick: Think of it like a bouncer at a club—only lets certain things in or out.

Cytoplasm

fluid matrix that supports organelles inside the cell

Memory trick: “Cyto” = cell, “plasm” = goo. Imagine Jell-O holding fruit pieces (organelles)

Organelles

“little organs” inside the cell that perform specialized functions

Memory trick: Just like organs in your body, organelles keep the cell body alive

mitochondria

organelle is the site of energy (ATP) production through cellular respiration

Memory trick: Called the “powerhouse of the cell”—imagine a power plant lighting up a city

Ribosomes

proteins made in cells

Memory trick: Ribs = meat = protein.

endoplasmic reticulum (ER)

organelle transports materials and can be “rough” (with ribosomes) or “smooth” (without ribosomes)

Memory trick: Think of it as the cell’s highway system. Rough ER = trucks carrying proteins, Smooth ER = detox/chemical storage

Golgi complex

organelle modifies, packages, and ships proteins

Memory trick: Think of UPS/FedEx for the cell

Lysosomes

organelle contains digestive enzymes to break down waste or malfunctioning cell parts

Memory trick: “Lysol” cleans up messes → Lysosome cleans the cell.

Chloroplasts

contain chlorophyll, which is necessary for photosynthesis

Memory trick: “Chloro” = green → captures sunlight for food.

cell wall

essential for protection of the cell, the maintenance of the shape, and water balance

Memory trick: Think of a brick wall protecting a garden.

Vacuole

stores water, nutrients, or waste products (especially large in plants)

secretion, excretion, and storage

Memory trick: Like a vacuum bag storing stuff

Mitosis

cell division makes identical copies of cells for growth and repair

Memory trick: “Mitosis = My toes” → you need identical copies to grow.

Meoisis

cell division creates gametes (sperm and eggs) with half the number of chromosomes

Memory trick: “Meiosis = Make babies.”

Chromatin

loosely structured DNA in a non-dividing cell

Memory trick: Think of spaghetti DNA floating around.

Chromosomes

tightly packed DNA during cell division

Memory trick: Think of DNA “packing into suitcases” before traveling to new cells.

tissues

groups of cells with a common structure and function

Memory trick: Tissue = “team” of cells working together

What are the four main types of tissues?

Muscle, epithelial, nervous, connective.

Memory trick: MENC = Muscle, Epithelial, Nervous, Connective.

organ

structure made of different tissues that performs a specialized function

organ system

group of organs working together for a major function

organism

highest level of organization in biology

(complete living thing)

muscle tissue

(skeletal, cardiac, and smooth)

epithelial tissue

(skin, the lining of organs)

nervous tissue

(neurons)

connective tissue

(cartilage, blood, fat, bone)

Diffusion

movement of particles from high to low concentration without energy

Memory trick: Perfume smell spreading in a room.

Osmosis

diffusion of water across a selectively permeable membrane

Memory trick: Think “Osmosis Jones” (movie about water in the body).

Active transport

transport requires ATP energy to move substances

Memory trick: Active = energy (like exercising).

Passive transport

type of transport does not require energy

Memory trick: Passive = lazy, no energy needed.

Facilitated transport

form of passive transport that involves the use of membrane proteins

Isotonic

solution has equal solute concentration inside and outside the cell

Memory trick: Iso = equal.

hypertonic

solution has more solute outside the cell, causing the cell to shrink

Memory trick: Hyper kids run around and get skinny (cell shrinks).

Hypotonic

solution has less solute outside the cell, causing water to enter and the cell to swell/burst

Memory trick: Hippo = fat/swollen.

Filtration

movement of water/solutes by fluid or hydrostatic pressure.pressure across a membrane

Memory trick: Coffee filter lets water through but holds grounds.

Who published On the Origin of Species in 1859?

Charles Darwin.

Natural selection

explains how traits that enhance survival are passed on to offspring

Memory trick: “Survival of the fittest.”

adaptation

inherited trait that increases survival in a given environment

Memory trick: Think of polar bears’ white fur = camouflage.

What evidence supports evolution?

Fossil record, biogeography, comparative anatomy, embryology, molecular biology.

Memory trick: F-B-A-E-M = Fossils, Bio, Anatomy, Embryo, Molecules.

What shows the order of vertebrate evolution?

Fish → amphibians → reptiles → mammals/birds.
💡 Memory trick: “FARM-B” = Fish, Amphibian, Reptile, Mammal/Bird.

Taxonomy

science of classifying organisms

Memory trick: “Taxi” organizes where people go → taxonomy organizes life

What are the five kingdoms

Animal, Plant, Monera (bacteria), Protist (protozoa, algae, and some molds), Fungi (molds, mushrooms, yeasts, and the like).
💡 Memory trick: A Pretty Friendly Monkey Party = Animal, Plant, Fungi, Monera, Protist.

What is the correct order of classification levels?

Kingdom → Phylum → Class → Order → Family → Genus → Species.
💡 Memory trick: King Philip Came Over For Good Soup.

What is the scientific name format?

A: Genus (capitalized) + species (lowercase), e.g., Escherichia coli.
💡 Memory trick: Always Genus before species → like “First name then last name.”

Microbiology

study of microscopic organisms\Memory trick: “Micro” = small, “bio” = life.

What are bacteria, and why are they important?

Single-celled microorganisms with a cell wall but no nucleus or organelles

Functions of beneficial bacteria:

1. Aid digestion 🍽

2. Help make foods & antibiotics 🥛💊

3. Destroy harmful bacteria that cause disease ❌🦠

4. Supply nutrients for energy ⚡

5. Clean up environmental contaminants/spills 🧹

Pathogens

disease-causing microorganisms

What are the three shapes of bacteria?

Cocci (spherical), Bacillus (rod-shaped), Spirochetes (spiral).

💡 Memory trick: CBS = Cocci, Bacillus, Spiral.

What staining method classifies bacteria as positive or negative?

Gram staining.

💡 Memory trick: “Gram = Grandma” → she labels everything positive or negative.

Mycology

study of fungi called

What are fungi, and what are their key characteristics and roles?

• Microorganisms that can be single-celled or multi-celled 🍄

• Have a nucleus and organelles inside a cell membrane

• Surrounded by a rigid cell wall → gives shape and protection 🛡

• Reproduce mainly through spores 🌱

• Examples: yeast, mushrooms, mold

• Roles of fungi:

  1. Nutrient cycling & decomposition ♻

  2. Mutualistic relationships with plants 🌿

  3. Can cause diseases in plants and animals ❌

Phycology

study of algae

What are algae, and what are their main characteristics?

• Can be microscopic or very large 🌊

• Can be single-celled or multi-celled

• Contain a nucleus 🧬

• Mostly live in fresh or salt water 🌊

• Use sunlight to make food (photosynthesis) ☀

• Can grow on rocks, soil, or plants if moist 🌱

• Different from land plants → lack typical plant structures

Protozoology

study of protozoa

What are protozoa, and what are their key characteristics and roles?

• Single-celled microorganisms 🦠

• Lack cell walls, like animal cells

• Most ingest food particles; some use photosynthesis ☀

• Many are motile → move using cilia, flagella, or pseudopodia 🏃‍♂

• Mostly free-living in water, sometimes soil or sand 🌊🌱

• Some live inside other organisms → can be harmless or cause disease ⚠

  • Example: malaria caused by parasitic protozoa 🦟

• Symbiotic relationship: both species benefit 🤝

• Parasitic relationship: one benefits, other is harmed ❌

• Antibiotics don’t work on protozoa

• Antiprotozoal drugs may be used, sometimes with antibiotics in creams/ointments 💊

Virus

consist of DNA or RNA surrounded by protein

Why are viruses considered borderline living

They lack a nucleus, don’t metabolize energy, can’t reproduce without a host.
💡 Memory trick: Viruses are “half alive” → like zombies.

What is MRSA an example of

Antibiotic-resistant bacteria.

Memory trick: “Superbug” = can’t be killed easily.

Autotrophs

organisms make their own food from inorganic sources

producers

💡 Memory trick: Auto = self, troph = feed.

Heterotrophs

organisms must consume other organisms for food

consumers

Memory trick: Hetero = other.

What are the levels of consumers?

Primary (herbivores/omnivores), Secondary (carnivores/omnivores), Tertiary (carnivores eating carnivores).
💡 Memory trick: Think of a food chain ladder.

Decomposers

bacteria, fungi

breaks down nonliving organic material and recycles nutrients

Food chain

path of energy transfer in an ecosystem

Food web

interconnection of many food chains

Biotic

living

Abiotic

nonliving like temperature, soil, humidity

Mutualism

relationship where both species benefi

Parasitism

One benefits, the other is harmed

Commensalism

One benefits, the other is unaffected

Memory trick: Commuter on a train → gets a ride, train isn’t harmed.

What are the five main terrestrial biomes?

Desert, Tropical Rainforest, Deciduous Forest, Coniferous Forest, Tundra.
💡 Memory trick: Don’t Try Driving Cars Too-fast = Desert, Tropical, Deciduous, Coniferous, Tundra.

Tropical rain forests

• Temperature: relatively constant 68°F–90°F 🌡

• Daylight: constant length throughout the year ☀

• Humidity & Rain: high humidity, 200–400 cm of rain/year 💧

• Biodiversity: most species of any area in the world 🌳🐒🦜

• Trees: grow very tall; strong competition for sunlight 🌲🌲

• Forest floor: receives little light 🌑

What are the key characteristics of deciduous forests?

• Found in temperate, mid-latitude regions 🌎

• Air has enough moisture to support large trees 💧🌳

• Deciduous trees (e.g., oaks, maples) drop leaves during dry months 🍂

• Temperatures vary widely between seasons 🌡❄☀

What are the key characteristics of coniferous forests (taigas)?

• Found at high, cool elevations 🌲🏔

• Seasons: short summers, long chilly winters ❄☀

• Dominated by conifer trees (e.g., pine, fir) 🌲

• Evergreen: do not shed leaves in cold, dry months 🍃

What are the key characteristics of tundras?

• Very cold temperatures ❄

• Found at high altitudes 🏔

• Only shrubs and bushes grow 🌿

• No trees 🌲❌

What is the formula for photosynthesis?

6CO₂ + 6H₂O + light → C₆H₁₂O₆ + 6O₂
💡 Memory trick: Carbon dioxide + water + light makes sugar + oxygen.

Cuticle

waxy layer on plant leaves that prevents water loss

Memory trick: Like chapstick for leaves.

Stomates

pores on the lower surface of the leaves that allow carbon dioxide to enter and oxygen to be released during photosynthesis without losing too much water

pores allow gas exchange in leaves

Memory trick: “Stoma = mouth” → plant mouths breathe CO₂ and O₂.

angiosperms

responsible for reproduction

sepals

in case the flower before it blooms 

Anther

plant structure produces pollen

part of the stamen

Memory trick: “Anther = Ant carrying pollen dust.”

Stigma

receives pollen in a flower

Style

connects stigma to ovary

Where does fertilization occur in plants?

Ovary, which contains ovules → seeds after fertilization.
💡 Memory trick: Just like humans, ovaries = egg holders.

Petals

flower attracts pollinators

Memory trick: Bright colors = “flower advertisement.”

What do ovary walls develop into after fertilization?

Fruit.
💡 Memory trick: Ovaries protect seeds → fruit protects babies.

Genes 

instructions for traits

Alleles

alternate forms of a gene

homozygous and who was this term created by

An individual with two identical genes for a trait is called purebred

Gregor Mendel

What is the law of dominance?

One trait (dominant) masks another (recessive).
💡 Memory trick: Big “T” covers little “t.”

What is the law of segregation?

Alleles separate during meiosis and recombine during fertilization.
💡 Memory trick: “Separate → Segregate.”

recessive trait is expressed only if

the individual has two recessive genes (tt)

What is the law of independent assortment?

Genes on different chromosomes are inherited independently.
💡 Memory trick: Traits shuffle like separate decks of cards.

What is codominance?

Both alleles are expressed equally (e.g., roan cattle).
💡 Memory trick: “Co = together.”

autosomes

non sex chromoseomes

What are sex-linked traits?

Traits carried on the X chromosome (e.g., color blindness, hemophilia).
💡 Memory trick: X marks the spot.

How many chromosomes do humans have?

46 total (23 pairs).
💡 Memory trick: 2 shoes, 23 pairs → 46.

Double helix

structure of DNA

Watson and Crick model 

Nucleotides

DNA building blocks

phosphate, sugar, base

phosphate group (PO4), a five-carbon sugar called deoxyribose, and a nitrogenous base

What are the DNA base pairs

A–T, G–C.
💡 Memory trick: Apples in Trees, Cars in Garages.

Replication

process makes identical DNA copies

What is transcription?

Making mRNA from DNA.
💡 Memory trick: DNA “transcribes” a message.