BIOL 1161: Organization, Microscopy, and Embryology

Vocabulary flashcards covering microscope components, structural organization, embryonic development stages, and primary germ layers.

Tissue

A group of cells with a similar function.

Arm

A microscope component that supports the body tube and lenses, used to carry the microscope.

Base

The broad and heavy support at the bottom of the microscope that gives the instrument stability.

Ocular

The lens located in the upper part of the microscope; monocular microscopes have one ocular, while binocular microscopes have two oculars.

Body Tube

The part of a microscope that holds the ocular at one end and the nosepiece at the other, containing a prism to reflect light towards the eye.

Revolving Nosepiece

A revolving device located at the lower end of the body tube that holds the objective lenses.

Objective Lenses

Lenses located on the revolving nosepiece, typically categorized into scanning, low, high, and oil lenses.

Stage

The horizontal platform upon which the slide rests on a microscope.

Diaphragm

A feature found beneath the stage that controls the amount of light passing through the specimen being viewed.

Light Source

Component of the microscope that provides adjustable illumination for viewing the specimen.

Focus Adjustment Knobs

Knobs located on either side of the microscope arm (coarse and fine) that move the stage or body tube up or down to adjust focus distance.

Parfocal

A feature where setting the distance of the stage to the revolving nosepiece on scanning power keeps it set for all three objective lenses for that slide.

Development

A series of orderly, precise steps that transform a zygote into a multicellular embryo.

Cell Differentiation

The changing of unspecialized embryonic cells into specialized cells, tissues, and organs.

Cleavage

The first major phase of embryonic development characterized by rapid mitotic cell divisions without growth that creates a multicellular embryo from a zygote.

Morula

An early stage in embryonic development consisting of a solid ball of cells.

Blastula

An embryonic stage consisting of a single layer of cells surrounding a fluid-filled cavity called the blastocoel.

Blastocoel

The fluid-filled cavity surrounded by a single layer of cells within a blastula.

Gastrulation

The second major phase of embryonic development where cells move inward, adding cells, sorting them into three distinct cell layers, and transforming the blastula into a gastrula.

Ectoderm

The outer embryonic germ layer that gives rise to the epidermis (skin) and the nervous system.

Endoderm

The inner embryonic germ layer that gives rise to the lining of the digestive tract, organs associated with digestion, and the respiratory system.

Mesoderm

The middle embryonic germ layer that gives rise to muscle, bone, blood, the circulatory system, the excretory system, and in some animals, the respiratory system.

Epithelium

Tissue that covers all internal or external openings in the body and is separated from other tissue by a basement membrane.

Basement Membrane

A specialized structure that separates epithelial tissue from other underlying tissue.