Gen Bio 2:T2

Test 2

Simple Multicellularity

Multicellularity that have the traits:

Thin layers

Colony like

All cells are in contact with surface

Adhesion Molecules used

Complex Multicellularity

Multicellularity with traits:

Special pathways for cell communication

Exclusive to eukaryotes

All genetic clones

Most cells not in contact with world

Extracellular matrix (ECM)

A large network of proteins and other molecules that surround, support, and give structure to cells and tissues in the body. (proteins +polysaccharides)

Collagen

Fibrous component of ECM, mostly cable like forming flexible fibers that form layers (like rebar)

Proteoglycans

Surrounding substance of ECM, proteins attached to polysaccharides, attracts water to create a gel (like concrete)

Integrin

Fibrous component of ECM

Links the cytoskeleton of the cell interior with the ECM via fibronectin(a glycoprotein)

Connects the Insides to the outsides

Elastin

Fibrous component of ECM

Allows the ECM to expand and contract (lots would be found in lungs)

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Tight Junctions

Connection that seals the cell together

Gap junction

Connection that allows ions and small hydrophobic molecules pass through the cytoplasm of adjacent cells

Epithelial Tissue

Act as a barrier between the external and internal environments( found in skin, lungs, etc)

Desmosomes

Connection that attaches the cytoskeletons of adjacent cells to one another.

Apical Membrane

the part of the plasma membrane of a polarized cell that forms the surface facing the lumen.

Basolateral Membrane

the fraction of the plasma membrane at the bottom side of the cell, which faces adjacent cells and the underlying connective tissue.

Cadherins

Integral Membrane proteins that interact with cytoskeleton fiber, and with the same protein found in adjacent cells. Part of Desmosomes.

Hemidesmosomes

Connector protein that anchors the cell to the ECM rather than cell to cell

Connexons

monomer that forms a polymer that forms a channel to connect the cytoplasm of adjacent cells

Tissue

Group of cells of the same type that work together to preform a common function.

Organ

Structure made of two or more different tissues that function together

Connective Tissue

The cells that are embedded in the extracellular matrix. Gives support and protection. The cells are loosely arranged in a liquid, gel or solid matrix.

(ie. blood, bone, adipose tissue, tendons, ligaments)

Organ System

Two or more organs that work together to carry out a function .

Nervous Tissue

Tissue that conducts electrical signals.

Muscle tissue

Tissue that contracts to generate force, has three kinds.

Skeletal Muscle

Fibers that contract in response to information from nerves.

Skeletal Muscle Function

Allows voluntary body movement

Skeletal Muscle Structure

Muscle that has long cells that give a striped appearance

Cardiac Muscle

Makes up the walls of the hear

Cardiac Muscle Function

Involuntary contractions that help pump blood.

Cardiac Muscle Structure

Muscle that is made of branched cells

Smooth Muscle

Lines many organs especially the digestive track

Smooth Muscle Function

Allows the involuntary contraction of organs

Smooth muscle Structure

Muscle with cells that have a tapered apperance

Metabolic rate

The overall rate of energy consumption of an organism, dependent on activity, temperature etc.

Primary Cell wall

The name for what the cells first secrete made up of initial fibrous components

Secondary Cell wall

Once the plant stops growing they may secrete this. Its found between the plasma membrane and the primary cell wall. It can contain and be made up of different substances based on the kind of plant.

Middle lamella

Located between the cell walls of adjacent plant cells, Composed of pectin that attract water to forma jelly like layer that allows the cells to adhere to one another.

Cellulose

Fibrous component of the Plant cell wall (ECM)

Bundles into cable like microfibrils

It is a __polysaccharide__ consisting of chains of glucose __monomers__.

Pectin

The surrounding substance in the plant cell wall(ECM)

Gelatinous polysaccharide

plasmodesmata

Gaps that are created between cell walls. Connects the cytoplasm of each plant cells

Symplastic route

Dissolved solutes move directly between cells through a continuous network of cytoplasm. (plasmodesmata)

Apoplastic route

Dissolved solutes moving freely throughout the extracellular space, cell wall, middle lamella, plasma membrane

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Root system

The underground parts of the plant that anchor, take in water, and nutrients

Shoot system

The above ground part of the plant that harvests light and energy

Phenotypic Plasticity

Phenotypic variation within species due to differences in environment condition

Morphological diversity

The great reason many root system look incredibly different even though they live next to each other in the same area.

Modified roots

The way that plants roots are different based on their main function and environment. May not just do the job of getting water and nutrients from soil.

Adventitious Roots

Roots that grow from the shoot system and not the root system

Node

Where the leaves attach to the plant

Internode

Segments between the nodes of the plants

Leaves

The photosynthetic organs of the plant

Axillary/ lateral bud

Located at the nodes and may grow into a branch under the correct conditions

Stem

the main stalk of a plant that develops buds and shoots and usually grows above the ground.

Apical bud

Located at the tip of the stem or branch, this is where cells divide and grow, extending the length of the stem or branch

Stolon

An adaption of stems where new individuals at nodes are created above ground (strawberries)

rhizome

An adaption of the stem that stores carbohydrates and can grow into new plants from nodes that are underground

Tuber

Swollen rhizomes that function as carbohydrate storage organs (hint potato’s)

Vacuole

An organelle in plants which contains the aqueous cell sap an may store water nutrients and waste

Cell sap

a fluid found in the vacuoles (small cavities) of the living cell; it contains variable amounts of food and waste materials, inorganic salts, and nitrogenous compounds.

Meristematic cells

Undifferentiated cells that continue dividing

Primary Maristems

Partially differentiated but retain the character of meristematic cells because they keep dividing

Differentiated cells/ Non Meristematic Cells

Cells that are no longer are dividing and are found in the plants permanent tissue. These develop from meristems

Totipotent

Of an __immature__ or stem cell) capable of giving rise to any cell type or (of a __blastomere__) a complete __embryo__.

Dermal Tissue

The outer covering of the plant

Ground Tissue

Carries out the photosynthesis, stores photosynthetic products, and helps support the plant.

Vascular Tissue

This is what conducts water and solutes throughout the plant.

Epidermal Cells

Protect the surface of the plant

Stomata

regulates the gas exchange and water loss

Parenchyma

1 part of ground tissue, workhorse cells and tissues. Simple tissue with thin primary cell walls. Abundant and Versatile.

collenchyma

1 part of ground tissue, mostly shoot system support (think column). Simple tissue.

sclerenchyma

1 part of ground tissue that gives support. These cells have a thin primary cell wall and a thick rigid secondary cell wall. There is two kinds Fibers and sclereids

fibers

elongated cells that make up half of the sclerenchyma

Sclereids

Wide cells that make up half of the sclerenchyma

Xylem

conducts water and dissolved nutrients from the foot to the shoot system

Phloem

Conducts sugars, amino acids , hormones and other substances from root to shoot or shoot to root.

Trachieds

A part that makes up the xylem, has pits that allow water to move (a water conducting cell) dead at maturity (all vascular plants)

Vessel elements

apart of the xylem, dead at maturity, short and wide, have perforations as well as pits, water transport cells (angiosperms)

Water potential

The measure of potential energy water has in a particular environment relative to the potential energy of pure distilled water at room temperature and atm (moves words more negative values) Made up of two parts, solute and pressure potential

solute potential

***The component of water potential that is due to the presence of solute molecules***. It always has a negative value bc 0 is pure water so the more solutes make it more negative.

Pressure potential

a part of water potential that depends of whether pressure is applied on water or on a solution and in what direction (positive or negative)

Turgor Pressure

the force within the cell that pushes the plasma membrane against the cell wall

Turgid

cells or tissues that are swollen from water uptake

Flaccid

They are not plump and swollen but floppy or loose, and cells have drawn in and pulled away from the cell wall.

Cortex

Made up of ground tissue, ***an outer layer of a stem or root in a vascular plant***, lying below the epidermis but outside of the vascular tissues like phloem and xylem.

Endodermis

a cylindrical layer if cells that forma boundary between the cortex and vascular tissue

Casperian strip

Part of the cell wall that is filled with wax and blocks the apoplastic route at the endodermis, this forces ions and solutes to flow through the plasma membrane and not just travels through the pours in the cell walls. Act as a gate keeper

Pericycle

Lies just inside the endodermis, forms the outer layer of the vascular tissue

Transmembrane route

The is a route of water transport, that goes through the membrane between cells

Cohesion tension Theory

The idea on how water moves through the xylem, force is generated by transpiration ( as well as water potential)

Adhesion

How water molecules stick to surfaces like glass and will pull up on the perimeter

Cohesion

How water molecules stick to one another at the surface and hydrogen bond with nearby water molecules.

Surface Tension

Is between the water molecule that are at the air and water boundary, because these water molecules can form hydrogen bonds with molecules next to them and below them , the enhanced attraction minimizes the total surface area.

Bulk Flow -Plants

Mass movement of molecules along a pressure gradient, allowed by the xylem

Sieve Tube elements

The actual conducting cells for the phloem, lack nuclei and most organelles, have pores (enlarged plasmodesmata) that create a direct connection

Companion Cells

Adjacent to sieve tube elements and support their metabolism, packed with organelles seen as a support staff

Source tissues

Places where sugars are produced, mature leaves and stems

Sink tissues

Where sugars exit the phloem, meristems, flowers, developing seeds, fruits, roots, immature leaves

Translocation

The movement of sugars through the phloem in multiple direction, source to sink, the direction is dependent on the plant and the time of year

Zone of Maturation

The area just above the root tip where most nutrient uptake happens

Zone of nutrient depletion

The area in which the root hairs have been taking in all the nutrients, so the root tip has to keep growing

Metallothionein and phytochelatins

Small proteins and short peptides bind to metal ions and prevent them from acting as a poison

Parasitic plants

lives in or on hots and obtains water or nutrients from the host. Overall decreasing the fitness of the host