Zoology

Organ

Structural unit consisting of two or more tissues capable of carrying out specific tasks

Organ system

Two or more organs and other components
interact physically, chemically, or both in a common task

Tissues

group of cells of a similar type

epithelial tissue

Sheetlike layer of cells with little extracellular matrix between them

skin, hair, nails

examples of epithelial tissues

epithelial tissue

Tight junctions occur only in ___

exocrine

type of gland; ducts or tubes deliver the secretions

endocrin gland

type of gland; do not have ducts, release hormones into a body fluid

connective tissue

Cells scattered in an extracellular matrix of their own secretions

dense irregular connective

Function: able to withstand tension exerted in many directions; provides stuctural strength.

Location: Fibrous capsules of organs and of joints; dermis of the skin; submucosa of digestive tract.

dense regular connective tissue

Function: attaches muscles to bones or to muscles; attaches bones to bones; withstands great tensile stress when pulling force is applied in one direction

Location: tendons, most ligaments, aponeuroses

Specialized connective tissues

consists of adipose, cartilage, bone, and blood.

muscle tissue

* Pulls on bones to move body parts
* Cells are long and cylindrical
* Have a striated (striped) appearance

voluntary muscle

can deliberately make the cells contract; stores glycogen

cardiac muscle tissue

specialized muscle tissue found only in the heart

Smooth muscle tissue

In the walls of some blood vessels and internal organs; usually involuntarily controlled; not striated

nervous tissue

A body tissue that carries electrical messages back and forth between the brain and every other part of the body.

sensory, interneurons, motor neurons

types of neurons

neuroglial cells

* Keep neurons positioned where they should be
* Provide neurons with nutrients
* Wrap around the cytoplasmic extensions
* Speed the rate of electrical signal travel

Matthias Schleiden

A German Scientist that conclude that all plant parts are made of cells.

Theodor Schwann

concluded that all animal parts are made of cells.

Rudolf Virchow

discovered that cells couldn't develop from anything but other cells.

Prokaryotic and Eukaryotic

The two types of cells are ___ (without nucleus) and ____ (with nucleus).

Organelles

Structures that enable the cell to live, grow, and reproduce

cell membrane

gate into the city; outer layer of cell, allows nutrients into the cell and wastes outside of the cell

Cytoplasm

a jelly-like fluid contained in the cell that holds the organelles.

Nucleus

'mayor's office'; control center of the cell, contains the cell's DNA

Mitochondria

'electric company of the cell', power center, provides the energy the cell needs to move, divide, etc.

Ribosomes

"Factories of the cell"
• Site where proteins are made
• Cell parts are
made of proteins

Endoplasmic Reticulum

'roadways of the cell'; a cell structure that forms a maze of passageways in which proteins and other materials are carried from one part of the cell to another.

Rough Endoplasmic Reticulum

System of internal membranes within the cytoplasm. Membranes are rough due to the presence of ribosome, functions in transport of substances such as proteins within the cytoplasm

Smooth Endoplasmic Reticulum

no ribosomes; creates lipids or fat

Golgi complex

'UPS of the cell'; packaging house of cell, organelle that packages and distributes proteins

Lysosomes

'police men'; n organelle containing digestive enzymes -digests food particles and cell parts; protects cell by digesting foreign invaders

Vacuole

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

cell wall

• Found only in plant cells
• Protects and supports the cell

Chloroplast

• Found only in plant cells
• Contains chlorophyll (makes plants green)
• Where photosynthesis takes place

Mitosis

The process of cell division which results in the production of two daughter cells from a single parent cell.

Prophase

first and longest phase of mitosis, during which the chromosomes become visible and the centrioles separate and take up positions on the opposite sides of the nucleus

Metaphase

Chromosomes line up in the middle of the cell

Anaphase

Phase of mitosis in which the chromosomes separate and move to opposite ends of the cell

Telophase

- DNA spreads out - 2 nuclei form
- Cell wall pinches in to form the 2 new daughter cells

Meiosis

is the type of cell division by which germ cells (eggs and sperm) are produced.

Meiosis

During ____, DNA replicates once, but the nucleus divides twice

Prophase 1

Each chromosome duplicates and remains closely associated. These are called sister chromatids.

Metaphase 1

Paired homologous chromosomes line up across the center of the cell

Anaphase 1

Chromosome pairs separate with sister chromatids remaining together.

Telophase 1

2 daughter cells are formed, each daughter cell contains only one chromosome of the homologous pair.

Prophase 2

DNA does not replicate

Metaphase 2

chromosomes line up in the center of the cell

Anaphase 2

Centromeres divide and sister chromatids move separately to each pole.

Telophase 2

Cell division is complete.
Four haploid daughter cells are formed.

simple squamous epithelium

Structure: 1 layer of flat, tile-like cells
Function: diffusion and filtration
Location: blood vessels, lungs, heart, kidneys

simple cuboidal epithelium

Structure: 1 layer of square-shaped cells
Function: secretion
Location: glands, ovaries, kidneys

simple columnar epithelium

Structure: 1 layer of tall, narrow cells
Function: secrete mucus and absorption
Location: stomach, intestines, resp. tract

pseudostratified columnar epithelium

Structure: 1 layer of tall, narrow cells appears stratified but isn't
Function: secrete mucus and propel debris out of resp. tract (cilia)
Location: nasal cavity and trachea

stratified squamous epithelium

Structure: many layers of flat, tile-like cells Function: protect and acts as a barrier Location: skin, mouth, throat, esophagus

transitional epithelium

Structure: special type of stratified epi. changes
shape (stretched squamous, not stretched cuboidal)
Function: hold fluids
Location: urinary bladder

Free Cell Surfaces

ex is blood vessel, surface not in contact with other cells; smooth to reduce friction

Microvili

ex. is small intestine; increase cell's surface area

Cilia

ex. is trachea, move materials across cell's surface

goblet cells

ex. is stomach; produce mucus

tight junctions

bind adjacent cells together and form permeability barriers (ex. small intestines)

Desmosomes

Anchoring junctions that prevent cells from being pulled apart

Hemidesmosomes

anchor cells to the basement membrane

gap junctions

- small channels that allow molecules to pass
between cells
- allow cells to communicate
- most common

types of exocrine glands

simple, compound, tubular, and alveolus

Unicellular

Goblet cells in large and small intestine and respiratory passages

Simple straight tubular

glands in stomach and colon

simple coiled tubular

lower portion of stomach and small intestine

Simple acinar/alveolar

sebaceous glands of the skin

compund tubular

mucous glands of duodenum

compound acinar/alveloar

mammary glands

compound tubuloacinar/ tubuloalveolar

pancreas

loose connective tissue

Location: between organs, muscles, glands, skin
Structure: collagen fibers far apart
Function: support and protect

dense connective tissue

Location: tendons, ligaments, skin
Structure: collagen fibers packed close together
Function: connect and can withstand pulling forces

adipose connective tissue

Location: under skin and around organs Structure: collagen and elastic fibers, cells filled
with lipids
Function: storage, insulate, cushion

hyaline cartilage

Most common type of cartilage; it is found on the ends of long bones, ribs, and nose

it reduces friction thus acts as cushion

Fibrcartilage

Location: between vertebra
Structure: lots of collagen fibers
Function: can withstand compression

elastic cartilage

cartilage with abundant elastic fibers; ear and tip of nose

bone

• Hard connective tissue
• 2 types: compact and spongy
• Composed of osteocytes

blood

• Liquid connective tissue
• Erythrocytes, leukocytes, platelets
• Transport food, oxygen, waste, hormones

nervous tissue

• Consist of neurons or nerve cells
• Found in brain, spinal cord, and peripheral nerves • Controls and coordinates body movements
• Includes axons, dendrites, cell bodies

tissue repair

substitution of dead cells for viable cells

Regeneration

replacement of destroyed tissue by the same kind of cells (no scar)

replacement

cells of a different type develop (scar)

inflammation

• Occurs when tissues are damaged
• Signals the body's defenses (white blood cells) to destroy foreign materials and damaged cells so repair can occur.

chemical mediators

- released after injury
- cause dilation of blood vessels

Law of Segregation

Two alleles for each trait separate when gametes form; Parents pass only one allele for each trait to each offspring

law of independent assortment

Genes for different traits are inherited independently of each other

Genotype

The genetic makeup of an
organism; The gene (or allele) combination an organism has.

phenottype

The physical characteristics of an organism; The way an organism looks

Homozygous

Term used to refer to an organism that has two identical alleles for a particular trait (TT or tt)

Heterozygous

Term used to refer to an organism that has two different alleles for the same trait (Tt)

Incomplete Dominance

Situation in which one allele is not completely dominant over another.

Codominance

Situation in which both alleles of a gene contribute to the phenotype of the organism.

multiple alleles

Three or more alleles of the same gene.

polygenic traits

traits controlled by two or more genes