Macrocystis

Macronutrients

Madrone

Maiden-hair Tree

Maiden-hair fern

Magnolia

Male Gametangia

Mammals

Manganese

Magnesium

Mantle

(mycorrhizae on root)

Manure

Maple

Maple is the common name for the genus Acer in the division Anthophyta.  Maples are dicots, produce catkins and samaras as fruits.

Marchantia

                    DIAGRAM:  

                          PHOTO: Marchantia / Marchantia / Marchantia / Marchantia
                                          Marchantia / Marchantia / Marchantia / Marchantia
                                          Marchantia / Marchantia  / Marchantia / Marchantia
                                          Marchantia / Marchantia / Marchantia  / Marchantia

Margin

Marginal Meristem

Marine

Marsileales

                    DIAGRAM:  Marsileales

                          PHOTO:  

Mass Flow Theory

Matrix Potential

Matrix

(as in matrix potential)

Mechanical Stimuli

(callose and aperture size)

Medicinal

Mediterranean Climate

Megapascal

Megaphylls

Megasporangia

                    DIAGRAM:  

                          PHOTO:  Selaginella Strobilus Longitudinal Section

Megasporangiate Strobili

Megaspore

                    DIAGRAM:  

                          PHOTO:   Selaginella Strobilus Longitudinal Section
                                            Selaginella Strobilus Longitudinal Section

Megaspore mother cell

Megasporocyte

Megasprorophyll

                    DIAGRAM:

                          PHOTO: Selaginella Strobilus Longitudinal Section 

Meiosis

Memberanous Envelope

Membrane Potential

Meristem Zone

Meristem

Meristem is rapidly dividing embryonic tissue that adds new cells as a brick-layer lays new bricks, one row of cells on top of the former row.

                    DIAGRAM:  Root Anatomy

                          PHOTO:  Root Meristem Zone Longitudinal Section
                                           Root Meristem Zone Longitudinal Section
                                           Root Meristem Zone Longitudinal Section
                                           Root Meristem Zone Longitudinal Section

                                           Meristem Region of Anthoceros

Meristoderm

Mesocarp

Mesophyll

The mesophyll is the chlorenchyma cells (palisade layer and spongy layer) of the leaf.  The mesophyll is bordered on the top and bottom side by the epidermis and has the leaf veins embedded in it between the palisade and spongy layer.

                    DIAGRAM:  Vascular Cylinder / Root Anatomy

                          PHOTO:  Leaf Cross Section

Mesozoic

Metabolic Products

Metabolic Energy

Metabolism

Metaphloem

                    DIAGRAM:  

                          PHOTO:  Root Cross Section 

Metaxylem

                    DIAGRAM:  

                          PHOTO: Root Cross Section / Root Cross Section / Root Cross Section

Meters per Hour

Methane

Methanogens

Microclimate

Microfibrils

(as in cell wall)

Microorganisms

Micronutrients

Microphyll

                    DIAGRAM:  Equisetum Stem

                          PHOTO:  

Micropylar End

Micropyle

Microsporangia

                    DIAGRAM:  

                          PHOTO: Selaginella Strobilus Longitudinal Section
                                          Selaginella Strobilus Longitudinal Section
                                          Selaginella Strobilus Longitudinal Section 

Microsporangiate Strobili

Microspore Mother Cells

Microspores

                    DIAGRAM:  

                          PHOTO:  Selaginella Strobilus Longitudinal Section

Microsporocyte

Microsporophyll

                    DIAGRAM:  

                          PHOTO:  Selaginella Strobilus Longitudinal Section
                                           Selaginella Strobilus Longitudinal Section

Microtubules

                    DIAGRAM:  Microtubules

                          PHOTO:  

Mid-atlantic Ridge

Middle Lamella

The middle lamella is the material between adjacent cells of a plant.  It is essentially the "glue" that holds plant cells together.

                    DIAGRAM:  Pits

                          PHOTO:  

Middle Story

Midrib

Midwest

Migration

Mildews

Milkweed

Millimeters per Hour

Mimosa pudica

Mints

Minute

Mitochondria

                    DIAGRAM:  Mitochondria / Microtubules

                          PHOTO:  

Mitosis

Mitochondria

Mitochondria are the furnaces of the cells.  They are enclosed by a membrane with a folded membrane within.  This is where cellular respiration occurs to provide energy to the cell in the form of ATP.

Mobility

Modified Leaves

Modified leaves are structures that have their origin from a leaf bud.  Modified leaves typically do not look like leaves.  Good examples of modified leaves are tendrils, bud scales, onion scales, etc.

Modified Stems

Modified stems are plant organs that contain nodes and internodes just like stems except they don't look like stems.  A number of modified stems exist:  rhizomes, tubers, thorns, bulbs, corms, stolon, cladophylls, etc.

                    DIAGRAM:  Thorns

                          PHOTO:  

Moisture

Molds

Molybdenum

Monarch Root

Monera

Monkey Flowers

Monocots

Monocots are plants that are characterized by a single cotyledon (seed leaf) in the seed, parallel-veined leaves, vascular bundles scattered, flower parts in threes or multiples of threes, and no secondary growth.

                    DIAGRAM: Monocot Leaf \ Grass Leaf Structure

                                          Monocot Stem Intercalary Meristem

                                          Monocot Vascular Bundle
                                          Monocot Vascular Bundle

                          PHOTO: Monocot Stem Cross Section Vascular Bundle
                                          Monocot Stem Cross Section
                                          Monocot Stem Cross Section
                                          Monocot Stem Cross Section Vascular Bundle

                                          Monocot Root Cross Section
                                          Monocot Root Cross Section
                                          Monocot Root Cross Section
                                          Monocot Root Cross Section

                                          Narcissus / Narcissus / Narcissus / Narcissus / Narcissus
                                          Narcissus / Narcissus / Narcissus / Narcissus

                                          Monocot Ovary Cross Section
                                          Monocot Ovary Cross Section

Monocotyledonae

Monocultures

Monoecious Flower

Monopodial

Monopodial branching is where there is a main trunk with whorls of branches at each node. Pine and firs trees are good examples of this type of branching.

Monosaccharide

Moose

Mormon Tea

Morphology

The morphology of a biological entity is its outside structure and form.  It is what shows on the outside of a plant or animal body.  Morphology in animals refers to arms, legs, head, neck, nose, etc.  Morphology in plants refers to the form of the buds, lenticels, length of the internodes, etc.

Mosquito Larvae

Mosquito Fish

Mosses

                    DIAGRAM:  

                          PHOTO:  Mosses / Mosses / Mosses / Mosses / Mosses / Mosses

                                           Moss Leaf Cross Section
                                           Moss Leaf Cross Section

                                           Moss Stem Cross Section
                                           Moss Stem Cross Section

                                           Moss Capsule Cross Section
                                           Moss Capsule Cross Section
                                           Moss Capsule Cross Section
                                           Moss Capsule Cross Section
                                           Moss Capsule Cross Section

Moth Mullen

mRNA

                    DIAGRAM:  Ribosomes

                          PHOTO:  

Mucilaginous

Mulberry

Multicellular

Organisms that are multicellular are composed of many cells, with each cell within a tissue having a special physiological function, each tissue within an organ having a special physiological function, and each organ within the organism with its own special function.  Thus, multicellular organisms show division of labor.

Multiciliated

(sperm of equisetum)

Multinucleated

Multiple Fruits

Musci

Mushrooms

Musk-oxen

Muskeg

Mustard Family

                    DIAGRAM:  Brassicaceae

                          PHOTO:  

Mustards

Mutualism

Mycelium

                    DIAGRAM:  

                          PHOTO:  Puccinia Mycelium

Mycorrhizae