Freshman Biology Final Review

Flashcards of key vocabulary and concepts from biology lecture notes Units 1-4.

Homeostasis

A balanced state in an organism’s body.

Cellular Respiration

Convert energy in food into usable form (ATP).

Synthesis

Make complex compounds from simple substances.

Excretion

Remove wastes produced by metabolic activities.

Inorganic Molecules

Simple compounds & elements.

Organic Compounds

Large, complex molecules called polymers. Always contain the elements carbon and hydrogen. Synthesized from simpler substances called monomers (building blocks).

The four organic compounds

proteins, lipids, nucleic acids, and carbohydrates

Membrane Proteins

Part of cell membrane; help transport materials into and out of the cell, or receive chemical messengers such as neurotransmitters and hormones.

Neurotransmitters and hormones

Send messages throughout the body

Nucleic Acids

Polymers such as DNA and RNA; monomers are nucleotides (nitrogen bases - DNA has ATCG, RNA has AUCG)

Dehydration Synthesis

Join monomers to build polymers by removing molecules of water.

Hydrolysis

Break apart polymers into monomers by adding molecules of water

Cell Theory

All living things are made of one or more cells = structure; Cells perform all life processes = function; All cells come from pre-existing cells

Unicellular

Single celled organisms (bacteria, protozoa, algae)

Multicellular

Have more than one cell; may be just a few cells, or many trillions of cells. Almost all structures in many celled organisms are either made of cells or made by cells.

Molecules

Atoms bonded together. Compounds = 2 or more different elements bonded

Organelles

Cell structures that perform specific jobs.

Cells

Basic unit of all living things.

Systems

Groups of organs that work together for the same function.

Population

Members of the same species living in the same place at the same time.

Community

Many different populations living in the same place at the same time.

Prokaryotic cells

Do not have a nucleus (DNA floats in cell’s cytoplasm) and have few organelles.

Eukaryotic cells

Have a nucleus plus many organelles.

Nucleus

Controls the cell and contains hereditary material (chromosomes, genes, DNA)

Cytoplasm

Fluid/liquid inside the cell – mostly water plus dissolved substances, helps transport materials

Mitochondrion

Carries out cellular respiration and gives cell usable energy in the form of ATP (powerhouse of the cell)

Ribosome

Makes proteins by joining amino acids (protein synthesis)

Vacuole

Stores food or water or waste, plant cells have LARGE water vacuoles

Chloroplast

Contains chlorophyll and performs photosynthesis, found ONLY in plant cells and algae cells.

Cell Wall

Gives shape, structure and protection, found in plant cells. NEVER in animal cells.

Cell Membrane

Separates cell interior from outer environment. Made of two layers of phospholipids plus proteins embedded in the lipid layers. Controls what enters and leaves the cell using membrane proteins.

Passive Transport

Particles move through cell membrane without using energy.

Diffusion

Movement of substances from an area of high concentration to an area of low concentration.

Osmosis

Diffusion of water. Water moves into or out of the cell from an area of high concentration to an area of low concentration.

Active Transport

Substances move into or out of cells from an area of low concentration to an area of high concentration. Requires the use of energy (ATP) and membrane proteins called protein pumps.

Large Particle Transport

Allows very large substances through: Exocytosis = leave cell, Endocytosis = enter cell

Ingestion

Take nutrients into the body.

Digestion

Break down nutrients (polymers) into smaller molecules (monomers).

Autotroph Nutrition

Organisms take inorganic molecules (CO2 & H2O) and convert them into organic nutrients (including carbohydrates such as sugars and starches).

Autotroph

Makes its own food.

Heterotroph

Cannot make its own food.

Herbivores

Consumers (animals) that eat plants or algae.

Carnivores

Consumers (animals) that eat other animals.

Omnivores

Consumers (animals) that eat both plants and animals.

Decomposers

(fungi and some bacteria) that break down dead matter and waste. Decomposers are important decay organisms for recycling elements (C H O N).

Cellular Respiration

Process that takes energy stored in sugar molecules and places this energy into molecules of ATP.

ATP

The molecule all cells use for energy.

Photosynthesis

Process in which the sun’s energy is stored in the chemical bonds of sugar.

Chloroplast

Cell organelle (containing chlorophyll) that performs photosynthesis.

Stomata

Pores or tiny openings under a leaf. Let gases (CO2 O2 H2O) in and out.

Guard cells

Open and close the stomata to prevent plant from drying out.

Xylem and Phloem

Tubes transport water (xylem) and food (phloem) through the plant.

Food Chain

Shows one pathway for energy flow through an ecosystem.

Food Web

Shows many energy flow pathways through an ecosystem.

Producer

An autotroph; organisms that make their own nutrients from simple molecules (such as carbon dioxide and water during photosynthesis).

Consumer

A heterotroph; may be an herbivore (plant-eater), carnivore (animal-eater), omnivore (eats both plants and animals). Cannot make own food.

Decomposer

A heterotroph that decays dead organisms and returns (recycles) nutrients to the environment (including compounds containing nitrogen N2)

Energy Pyramid

Shows that energy is lost (used up) with each step in a food chain.

Circulatory System

Moves substances through the body to the organs, tissues and cells that need them.

Capillaries

Microscopic blood vessels where diffusion occurs. Connect arteries and veins.

Plasma

Liquid fluid of the blood that carries all blood cells. Mostly water (90%) plus dissolved nutrients, wastes, salts, hormones and antibodies.

Hemoglobin

Protein in red blood cells that carries oxygen O2.

Respiratory System

Provides oxygen O2 needed for cellular respiration and excretes the waste carbon dioxide CO2 which is produced from cellular respiration.

Alveoli

Microscopic air sacs inside the lungs where oxygen O2 enters the blood and carbon dioxide CO2 diffuses out of the blood and enters the air sacs.

Pathogen

An organism (germ) that causes an infectious disease.

Antibodies

Proteins made by white blood cells to attack pathogens. Every antibody is specific in its action - it can attack only one type of pathogen.

Antigens

Protein “tags” on pathogens that identify a bacteria or virus.

Vaccine

An injection to stimulate the body’s immune response against a specific disease. It uses either a dead pathogen, weakened pathogen, or messenger RNA to prepare the body to recognize a disease and produce antibodies.

Nervous System

Senses and responds to your external and internal environment and helps your body maintain homeostasis. The nervous system regulates your body with impulses that are both electrical and chemical.

Neurotransmitters

Proteins released by the end knobs of one nerve cell that diffuse across the space between neurons called the synapse, received by receptor molecules.

Endocrine System

Uses hormones to regulate the body and maintain homeostasis (stable internal environment).

Hormone

A chemical messenger (usually a protein) secreted by endocrine glands.

Feedback mechanisms

Cycles in which the product of one reaction causes another to start or stop.

Dynamic Equilibrium

A balanced state created by many small, opposing changes.

Excretory System

Removes metabolic wastes produced during chemical reactions by the cells of your body.

Haploid

Reduces normal chromosome number by one half

Diploid

Restores normal chromosome number

Trisomy

Mutation type resulting in the addition of chromosome

Monosomy

Mutation type resulting in the substraction of a chromosome

Genotype

The set of genes an organism possess

Phenotype

The expression of an organisms genes in their traits

Sex-Linked

A trait that is carried on the sex chromosomes

Evolution

gradual change over time

Natural Selection

The environment selects favorable traits such that species adapt

Reproductive Isolation

organisms change so much they are unable to interbreed

Speciation

When a single species evolves separately

Ecology

Study of the interactions of species among themselves and their environment

Niche

Role in an environment

Biotic Factor

Living things

Abiotic Factor

Non Living Things

Carrying Capacity

Maximum number of species allowed by environment

Examples of inorganic molecules

water, carbon dioxide, oxygen, nitrogen

main organs of the central nervous system

brain and spinal cord (made of interneurons)

meiosis

a type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes and plant reproduction cells.

mitosis

a type of cell division that results in two daughter cells each having the same number and kind of chromosomes as the parent nucleus

four main points of Darwin's theory

variation, inheritance, struggle for existence, and survival of the fittest

acquired characteristics

characteristics that happen during the organisms life time

three basic steps in natural selection

overproduction, competition, variations

homologous structures

similar body parts modified to preform different functions; indicate common ancestor

artificial selection

people choose which organisms to breed basic of traits that are valuable to the people