BIOL 211 FINAL PRACTICE

FINAL????

Isolecithal eggs

Eggs with a small amount of evenly distributed yolk, found in echinoderms and mammals.

Mesolecithal eggs

Eggs with a moderate amount of yolk concentrated toward one side, characteristic of amphibians.

Telolecithal eggs

Eggs with a large amount of yolk at one end, found in birds, reptiles, and fish.

Centrolecithal eggs

Eggs with yolk concentrated in the center, found in insects.

Radial cleavage

A pattern where cells stack directly above each other in neat rows, common in deuterostomes.

Spiral cleavage

A pattern where cells are offset and arranged in a spiral pattern, common in protostomes.

Blastulation

The process where the embryo becomes a hollow ball of cells called the blastula.

Blastocoel

The fluid-filled cavity inside the blastula.

Gastrulation

The process where cells move inward to form germ layers (ectoderm, endoderm, and sometimes mesoderm).

Ectoderm

The outer germ layer that develops into the skin and nervous system.

Endoderm

The inner germ layer that develops into the digestive tract lining and respiratory organs.

Mesoderm

The middle germ layer in triploblastic animals that develops into muscles, skeleton, and the circulatory system.

Diploblastic

Animals having two germ layers: ectoderm and endoderm.

Triploblastic

Animals having three germ layers: ectoderm, mesoderm, and endoderm.

Schizocoely

A coelom formation process where the mesoderm splits; common in protostomes.

Enterocoely

A coelom formation process where the cavity forms from pockets that pinch off the archenteron; common in deuterostomes.

Acoelomate

An organism with no body cavity, such as a flatworm.

Pseudocoelomate

An organism with a body cavity not completely lined with mesoderm, such as roundworms (nematodes).

Coelomate

An organism with a true coelom completely lined with mesoderm, such as annelids, mollusks, echinoderms, or chordates.

Amnion

An extraembryonic membrane that surrounds and protects the embryo in fluid.

Chorion

An extraembryonic membrane used for gas exchange.

Allantois

An extraembryonic membrane used for waste storage and gas exchange.

Yolk sac

An extraembryonic membrane used for nutrient storage.

Monotremes

Egg-laying mammals, such as the platypus and echidna.

Marsupials

Mammals whose young develop in a pouch after a short pregnancy, such as kangaroos and koalas.

Placental mammals

Mammals whose embryo develops fully inside a uterus with a placenta, such as humans and whales.

Holoblastic cleavage

Cleavage where the entire egg divides completely, occurring in mammals and amphibians.

Meroblastic cleavage

Partial cleavage that occurs only in part of the egg due to a large amount of yolk, occurring in birds, reptiles, and fish.

Blastopore

The opening that forms during gastrulation; it becomes the mouth in protostomes and the anus in deuterostomes.

Integument

The body covering, including skin and derivatives such as scales, feathers, hair, claws, and glands.

Sclerotization

The hardening of protein structures by cross-linking proteins, common in arthropod exoskeletons.

Calcification

The hardening of structures through the deposition of calcium salts, common in bones and shells.

Keratin

A strong structural protein found in skin, hair, nails, claws, feathers, horns, and scales.

Cornified cells

Dead cells filled with keratin that form a tough, protective outer layer.

Melanin

A pigment that provides color to skin, hair, and eyes, and protects against UV radiation.

Cellular respiration

A chemical process in cells that uses oxygen to release energy from food.

External respiration

The exchange of gases between the environment and respiratory surfaces like lungs or gills.

Internal respiration

The exchange of gases between the blood and body tissues.

Operculum

A structure in fish that covers and protects the gills and helps pump water over them.

Countercurrent flow

An efficient gas exchange mechanism in gills where water and blood move in opposite directions to maintain a concentration gradient.

Positive pressure ventilation

A method of breathing where air is pushed into lungs or gills, used by amphibians.

Negative pressure ventilation

A method of breathing where air is pulled into lungs by expanding the chest cavity, used by mammals.

Alveoli

Tiny air sacs in mammal lungs where gas exchange occurs between air and blood.

Pulmonary circuit

The circulatory route that moves blood between the heart and lungs for gas exchange.

Systemic circuit

The circulatory route that moves blood between the heart and the rest of the body.

Intracellular digestion

Digestion that occurs inside cells after food particles are engulfed.

Extracellular digestion

Digestion that occurs outside cells in a digestive cavity or tract.

Incomplete gut

A digestive system with a single opening that serves as both the mouth and the anus.

Complete gut

A digestive system with separate openings for the mouth and anus, allowing one-way food movement.

Homodont

Having teeth that are all similar in shape.

Heterodont

Having teeth specialized into different types.

Polyphyodont

The condition of having teeth that are continuously replaced throughout life.

Diphyodont

The condition of having two sets of teeth during life, baby teeth and adult teeth.

Rumen

The first chamber of a ruminant stomach used for storage and fermentation of cellulose by microorganisms.

Cecum

A digestive structure that uses bacteria to help digest plant material; it is typically larger in herbivores.

Gizzard

A digestive organ that mechanically grinds and crushes food, often using swallowed stones or grit.