BIOLOGY EXAM REVISION- AOS 1, AOS 2, AOS 3.

independent variable

The experimental factor that is manipulated; the variable whose effect is being studied.

dependent variable

The measurable effect, outcome, or response in which the research is interested.

independent variable

The experimental factor that is manipulated; the variable whose effect is being studied.

dependent variable

The measurable effect, outcome, or response in which the research is interested.

controlled variable

Factor in an experiment that a scientist purposely keeps the same

control

In an experiment, the standard that is used for comparison

extraneous variable

In an experiment, a variable other than the IV that might cause unwanted changes in the DV.

qualitative data

descriptive data

Quantitative data

numerical data

Hypothesis

A testable prediction, often implied by a theory

Reliability

consistency of measurement

Validity

the extent to which a test measures or predicts what it is supposed to

Precision

a measure of how close a series of measurements are to one another

Accuracy

how close a measurement is to the true value

Xylem

vascular tissue that carries water upward from the roots to every part of a plant

Phloem

Living vascular tissue that carries sugar and organic substances throughout a plant

Transpiration

Evaporation of water from the leaves of a plant

Translocation

The movement of sucrose and other substances like amino acids around a plant

Stomata

Small openings on the underside of a leaf through which oxygen and carbon dioxide can move

vascular plants

Plants that have tubes inside of them to transport liquid.

digestive system

Breaks down food into absorbable units that enter the blood for distribution to body cells.

excretory system

the system that removes waste from your body and controls water balance

endocrine system

Consists of glands that control many of the body's activities by producing hormones.

Homeostasis

process by which organisms maintain a relatively stable internal environment

negative feedback loop

A feedback loop in which a system responds to a change by returning to its original state, or by decreasing the rate at which the change is occurring.

positive feedback loop

a feedback loop in which change in a system is amplified

stimulus response model

Stimulus - receptor - control centre - effector - response

Thermoregulation

Process of maintaining an internal temperature within a tolerable range.

Osmoregulation

The control of water balance.

diabetes

A condition in which the body is unable to produce enough insulin, the hormone required for the metabolism of sugar

Hypoglycemia

abnormally low level of sugar in the blood

hyperglycemia

excessive sugar in the blood

Tissue

A group of similar cells that perform the same function.

Cells

Basic unit of life

Organs

Tissues are organized into:, group of tissues that work together to perform closely related functions.

Body Systems

groups of organs that perform specific functions in the human body

Organs of the digestive system

mouth, pharynx, esophagus, stomach, small intestine, large intestine, rectum

organs of the excretory system

kidneys, ureters, bladder, urethra

organs of the endocrine system

pituitary, thymus, thyroid, parathyroid, adrenal, and pineal glands; ovaries, testes, and pancreas

Prokaryote

A unicellular organism that lacks a well defined nucleus and membrane bound organelles

Eukaryote

A cell that contains a nucleus and membrane bound organelles

Unicellular

Made of a single cell

Multicellular

Consisting of many cells

surface area to volume ratio

Ratio of a cell's outside area to its internal volume.

Nucleus

A part of the cell containing DNA and RNA and responsible for growth and reproduction

plasma membrane

A selectively-permeable phospholipid bilayer forming the boundary of the cells

Ribosomes

site of protein synthesis

Chloroplast

An organelle found in plant and algae cells where photosynthesis occurs

Mitochondria

Powerhouse of the cell, organelle that is the site of ATP (energy) production

Endoplasmic Reticulum

A system of membranes that is found in a cell's cytoplasm and that assists in the production, processing, and transport of proteins and in the production of lipids.

Golgi body

A structure in a cell that receives proteins and other newly formed materials from the endoplasmic reticulum, packages them, and distributes them to other parts of the cell.

Vacuole

A sac inside a cell that acts as a storage area

cell wall

A rigid layer of nonliving material that surrounds the cells of plants and some other organisms.

Hydrophobic

water hating

Hydrophilic

water loving

Osmosis

Diffusion of water through a selectively permeable membrane

Diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration.

passive transport

Requires NO energy, Movement of molecules from high to low concentration, Moves with the concentration gradient

active transport

Energy-requiring process that moves material across a cell membrane against a concentration difference

facilitated diffusion

Movement of specific molecules across cell membranes through protein channels

Endocytosis

A process in which a cell engulfs extracellular material through an inward folding of its plasma membrane.

Exocytosis

Process by which a cell releases large amounts of material

isotonic solution

A solution in which the concentration of solutes is essentially equal to that of the cell which resides in the solution

hypertonic solution

Solute concentration is greater than that inside the cell; cell loses water

hypotonic solution

Solute concentration is less than that inside the cell; cell gains water

binary fission

A form of asexual reproduction in which one cell divides to form two identical cells.

Mitosis

cell division in which the nucleus divides into nuclei containing the same number of chromosomes

cell cycle

series of events that cells go through as they grow and divide

Interphase (Mitosis)

G1, S, and G2 phase of cell cycle
DNA is replicated in S phase

Prophase (mitosis)

chromatin condenses into chromosomes
centriole pairs separate,
nuclear membrane dissolves which allows spindle fibers to contact chromosomes

Metaphase (mitosis)

Chromosomes line up in the middle of the cell

Anaphase (Mitosis)

cell elongates and sister chromatids are pulled apart toward the poles

Telophase (mitosis)

the nuclei for the newly split cells form, the nucleoli reappear, and the chromatin uncoils

Cytokinesis

division of the cytoplasm

Apoptosis

process of programmed cell death

cancer cells

cells that grow and divide continuously at an unregulated pace

stem cells

undifferentiated cells

pluripotent stem cells

Stem cells that can become almost all types of tissues and cells in the body.

multipotent stem cells

stem cells that can become a limited number of types of tissues and cells in the body

totipotent stem cells

Stem cells that can differentiate into any type of specialised cells found in organisms of that species.