Biology Vocab Quiz Chapter 21/Chapter 8

Virus

Particle made of proteins, nucleic acids, and sometimes lipids that can replicate only by infecting living cells

Bacteriophage

Kind of virus that infects bacteria

Prokaryote

unicellular organism that lacks a nucleus

Binary fission

Type of asexual reproduction in which an organism replicates its DNA and divides in half, producing two identical daughter cells

Endospore

structure produced by prokaryotes in unfavorable conditions; a thick internal wall that encloses the DNA and a portion of the cytoplasm

Conjugation

process in which paramecia and some prokaryotes exchange genetic information

Pathogen

disease-causing agent

Vaccine

Preparation of weakened or killed pathogens used to produce immunity to a disease

Antibiotic

group of drugs used to block the growth and reproduction of bacterial pathogens

Protist

Are eukaryotes that aren’t found in fungi or plants and aren’t animals. Are a separate group of living things and majority are unicellular

Cilia

Hair-like structures found on the surface of many types of cells. Are important for movement and are used to nourish or feed organisms

Flagella

structure used by protest for movement; produces movement in wavelike motion

Fungi

Eukaryotic organisms that include microorganisms such as yeasts, mold, and mushrooms

Cell

basic unit of all forms of life

Cell Theory

fundamental concept of biology that states that all living things are composed of cells are the basic units of structure and function of living things and new cells are produced from existing cells

Cell Membrane

thin, flexible barrier that surround all cells; regulates what enters & leaves the cell

Nucleus

center of the atom containing protons and neutrons l contains the cell’s genetic material(DNA)

Eukaryote

organism whose cells contain a nucleus

Cytoplasm

fluid portion of the cell outside the nucleus

Organelle

specialized structure that performs important cellular functions within a eukaryotic cell

Ribosome

cell organelle consisting of RNA and protein found throughout the cytoplasm in a cell; the site of protein synthesis

Endoplasmic Reticulum

internal membrane system found in eukaryotic cells; place where lipid components of the cell membrane are assembled

Golgi Apparatus

organelle in cells that modifies, sorts, and packages proteins and other materials from the endoplasmic reticulum for storage in the cell or release outside the cell

Vacuole

Cell organelle that stores materials such as water, salts, proteins, and carbohydrates

Lysosome

cell organelle that breaks down lipids, carbohydrates, and proteins into smaller molecules that can be used by the rest of the cell

Cytoskeleton

network of protein filaments in a eukaryotic cell its shape and internal organization and is involved in internal movement

Chloroplast

organelle found in cells of plants and some other organisms that capture the energy from the sunlight and convert it to chemical energy

Mitochondria

Cell organelle that conversation the chemical energy stored in food into compounds that are more convenient for the cell to use

Cell Wall

Strong, supporting layer around the cell membrane in some cells

Lipid bilayer

flexible double-layered sheet that makes up the cell membrane and forms a barrier between the cell and its surroundings

Selectively permeable

property of biological membranes that allow some substances to pass across it while others can’t; also called semipermeable membrane

Homeostasis

relatively constant internal physical and chemical conditions that organisms maintain

Diffusion

process by which particles tend to move from n area where they are more concentrated to an area where they are less concentrated

Facilitated diffusion

process of diffusion in which molecules pass across the membrane through cell membrane channels

Aquaporin

water channel protein in a cell

Osmosis

diffusion of water through a selectively permeable membrane

Isotonic

when the concentration of two solutions is the same

Hypertonic

when comparing two solutions, the solution with the greater concentration of solutes

Osmotic Pressure

pressure that must be applied to prevent osmotic movement across a selectively permeable membrane

Tissue

group of similar cells that perform a particular function

Organ

collection of tissues that carry out a function or set of related ones often consist of the primary tissue that gives it its structure and function

Organ System

group of organs that work together to perform a specific function

Recpetor

On or in a cell, a specific protein to whose shape fits that of a specific molecular messenger, such as a hormone