BIOL3236 General Zoology Exam 1 Review

Vocabulary-style flashcards covering key terms from the lecture notes.

Lamarckism

Early evolutionary theory proposing that traits acquired during life can be inherited by offspring.

Inheritance of acquired characteristics

Core idea of Lamarckism; traits developed during an organism's life are passed to its descendants.

Perpetual change

Darwinian idea that life and environments are continuously changing, reflected in the fossil record.

Fossil record

Historically observed sequence of life forms showing changes through time.

Evolutionary trends

Directional changes in features or patterns of diversity over time.

Common descent

Idea that all living beings share a common ancestor.

Phylogeny

The evolutionary history and relationships among species, often depicted as a tree.

LUCA (Last Universal Common Ancestor)

Most recent common ancestor of all current life, dating back about 4 billion years.

Homology

Similarity due to shared ancestry, not convergence.

Phylogenetic reconstruction

Inferring evolutionary relationships from data such as morphology and genetics.

Speciation

Process by which one lineage splits into two or more species.

Allopatric speciation

Speciation caused by geographic separation of populations.

Dispersal

Movement of individuals into new areas leading to population divergence.

Colonization

Establishment of a new population in a new habitat after dispersal.

Vicariance

Geographic barrier splits a population, initiating divergence.

Sympatric speciation

Speciation occurring within the same geographic area due to ecological factors.

Allele frequency

Proportion of a specific allele in a population’s gene pool.

Gene pool

All the alleles present in a population.

Mutation

Creation of new alleles; source of genetic variation.

Genetic drift

Random changes in allele frequencies due to chance, especially in small populations.

Gene flow

Movement of alleles between populations via migration and interbreeding.

Natural selection

Differential survival and reproduction that increases favorable alleles.

Reproduction

Biological process of producing offspring.

Asexual reproduction

Offspring produced without fusion of gametes; clones of the parent.

Sexual reproduction

Offspring produced by fusion of gametes from two parents, increasing variation.

Gametes

Reproductive cells (sperm and eggs) carrying half the genetic material.

Gametogenesis

Production of mature gametes (spermatogenesis and oogenesis).

Spermatogenesis

Production of sperm in the testes.

Oogenesis

Production of eggs in the ovaries.

Oviparous

Reproduction by laying eggs outside the body.

Ovoviviparous

Eggs develop inside the mother with nourishment from yolk; live birth.

Viviparous

Live birth; embryos develop inside the mother with nourishment from her.

Preformation

Early idea that organisms are preformed in gametes or eggs.

Epigenesis

Development unfolds from undifferentiated material; new structures form over time.

Cleavage

Early embryo cell divisions increasing cell number without growth.

Blastula

Stage of a developing embryo that is a hollow ball of cells.

Gastrulation

Process forming multiple germ layers from the blastula.

Ectoderm

Outer germ layer giving rise to skin and nervous system.

Endoderm

Inner germ layer forming the gut lining and associated organs.

Mesoderm

Middle germ layer giving rise to muscles, bones, and circulatory systems.

Diploblastic

Organisms with two germ layers (ectoderm and endoderm).

Triploblastic

Organisms with three germ layers (ectoderm, mesoderm, endoderm).

Coelom

True body cavity lined by mesoderm.

Blastopore

First opening in embryonic development; fate determines protostome vs deuterostome.

Protostomes

Blastopore becomes the mouth; anus forms later in development.

Deuterostomes

Blastopore becomes the anus; mouth forms from a second opening.

Amniotes

Reptiles, birds, and mammals whose embryos develop in an amniotic sac.

Amnion

Fluid-filled sac surrounding the embryo in amniotes.

Amniotic egg

Egg with protective membranes enabling terrestrial development.

Hierarchical organization: Protoplasmic

Lowest level; unicellular organisms with differentiated protoplasm.

Cellular

Level where cells aggregate and perform specialized functions.

Tissue

Group of similar cells organized for a common function.

Organ

Structure composed of multiple tissues performing a function.

Organ-system

Group of organs coordinating to perform major bodily functions.

Animal body plans

Variations in organization, symmetry, germ layers, and body cavities.

Symmetry: spherical

Symmetry around a central point; common in some simple organisms.

Radial symmetry

Can be divided into similar halves by multiple planes around a axis.

Bilateral symmetry

Can be divided into two mirror halves along a sagittal plane.

Epithelial tissue

Tissue that lines surfaces and cavities and forms glands.

Connective tissue

Type of tissue that supports, binds, and protects organs.

Muscular tissue

Tissue specialized for contraction and movement.

Nervous tissue

Tissue that transmits nerve signals.

Histology

Study of tissues and their structure.

Germ layers

Ectoderm, endoderm, and mesoderm formed during development.

Protostomes vs Deuterostomes

Two developmental modes distinguished by blastopore fate.

Amniotic egg development

Amniotes develop inside protective membranes within an egg.

Embryology terms: cleavage, blastula, gastrulation

Key early developmental stages leading to germ layers.