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26.13: M

Created by: CK-12
macroevolution
evolutionary change that occurs over geologic time above the level of the species
macronutrient
nutrient such as carbohydrates, proteins, lipids, or water that is needed by the body in relatively large amounts
malaria
disease caused by Plasmodium protozoa and transmitted by mosquitoes in tropical and subtropical regions of the world
mammal
endothermic, tetrapod vertebrate that lays amniotic eggs and has mammary glands (in females) and hair or fur
mammary gland
gland in female mammals that produces milk for offspring
mantle
layer of tissue that lies between the shell and body of a mollusk and forms a cavity, called the mantle cavity, that pumps water for filter feeding
marine biome
aquatic biome in the salt water of the ocean
marsupial
therian mammal in which the embryo is born at an early, immature stage and completes its development outside the mother’s body in a pouch on her belly
mass extinction
extinction event in which many if not most species abruptly disappear from Earth
matter
anything that takes up space and has mass
mechanical digestion
physical breakdown of chunks of food into smaller pieces by organs of the digestive system
medusa (plural, medusae)
basic body plan in cnidarians such as jellyfish that is bell-shaped and typically motile
meiosis
type of cell division in which the number of chromosomes is reduced by half and four haploid cells result
melanin
brown pigment produced by melanocytes in the skin that gives skin most of its color and prevents UV light from penetrating the skin
memory cell
lymphocyte (B or T cell) that retains a “memory” of a specific pathogen after an infection is over and thus provides immunity to the pathogen
menarche
beginning of menstruation; first monthly period in females
menopause
period during which menstrual cycles slow down and eventually stop in middle adulthood
menstrual cycle
monthly cycle of processes and events in the ovaries and uterus of a sexually mature human female
menstruation
process in which the endometrium of the uterus is shed from the body during the first several days of the menstrual cycle; also called monthly period
meristem
type of plant tissue consisting of undifferentiated cells that can continue to divide and differentiate and from which plants grow in length or width
mesoderm
embryonic cell layer in many animals that is located between the endoderm (inner cell layer) and ectoderm (outer cell layer)
mesophyll
specialized tissue inside plant leaves where photosynthesis takes place
Mesozoic Era
age of dinosaurs that lasted from 245–65 million years ago
messenger RNA (mRNA)
type of RNA that copies genetic instructions from DNA in the nucleus and carries them to the cytoplasm
metabolism
sum of all the biochemical reactions in an organism
metamorphosis
process in which a larva undergoes a major transformation to change into the adult form, which occurs in amphibians, arthropods, and other invertebrates
metaphase
second phase of mitosis during which chromosomes line up at the equator of the cell
microevolution
evolutionary change that occurs over a relatively short period of time within a population or species
micronutrient
nutrient such as a vitamin or mineral that is needed by the body in relatively small amounts
migration
regular movement of individuals or populations each year during certain seasons, usually to find food, mates, or other resources
mineral
chemical element such as calcium or potassium that is needed in relatively small amounts for proper body functioning
mitochondria (singular, mitochondrion)
organelle in eukaryotic cells that makes energy available to the cell in the form of ATP molecules
mitosis
process in which the nucleus of a eukaryotic cell divides
model
representation of part of the real world
molecular clock
using DNA (or proteins) to measure how long it has been since related species diverged from a common ancestor
Mollusca
phylum of invertebrates that are generally characterized by a hard outer shell, a mantle, and a feeding organ called a radula
molting
process in which an animal sheds and replaces the outer covering of the body, such as the exoskeleton in arthropods
monosaccharide
simple sugar such as glucose that is a building block of carbohydrates
monotreme
type of mammal that reproduces by laying eggs
motility
the ability to move
motor neuron
type of neuron that carries nerve impulses from the central nervous system to muscles and glands
mucous membrane
epithelial tissue that lines inner body surfaces and body openings and produces mucus
mucus
slimy substance produced by mucous membranes that traps pathogens, particles, and debris
multiple allele trait
trait controlled by one gene with more than two alleles
muscle fiber
long, thin muscle cell that has the ability to contract, or shorten
muscle tissue
tissue made up of cells that can contract; includes smooth, skeletal, and cardiac muscle tissue
muscular system
human body system that includes all the muscles of the body
mutagen
environmental factors that causes mutations
mutation
change in the sequence of bases in DNA or RNA
mutualism
type of symbiotic relationship in which both species benefit
mycelium
body of a fungus that consists of a mass of threadlike filaments called hyphae
mycorrhiza
mutualistic relationship between a plant and a fungus that grows in or on its roots
myelin sheath
lipid layer around the axon of a neuron that allows nerve impulses to travel more rapidly down the axon
MyPlate
visual guideline for balanced eating, replacing MyPyramid in 2011
MyPyramid
visual dietary guideline that shows the relative amounts of foods in different food groups that should be eaten each day

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Feb 23, 2012

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Nov 25, 2014
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CK.SCI.ENG.SE.1.Biology.26.13

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