Sources of Taxonomic Information

Flashcards about sources of taxonomic information for exam review.

Which source of taxonomic information has been the most popular and important since the earliest classifications?

Morphology, the outer appearance of a plant, has historically been and continues to be the most popular and important source of taxonomic information.

What discovery allowed for the use of anatomy in plant classification?

The discovery of lenses and the microscope enabled the use of anatomy, the internal structures of plants, as a source of taxonomic information.

Why is chemistry important in plant classification?

Plants that are closely related tend to produce the same chemicals, making chemistry a valuable tool for classification.

What type of data is considered taxonomically significant?

Any data that shows differences from species to species is of taxonomic significance and forms part of the taxonomic evidence for classification.

Why is morphology still the most commonly used basis for classification systems?

Morphology forms the basis of virtually all classification systems and is still the most commonly used because it is easy to observe and practical for the user.

Why can vegetative characters be unreliable in plant classification?

Vegetative characters, related to non-reproductive parts, can be unreliable due to convergent evolution, where the same trait evolves in unrelated lineages.

What does reproductive morphology examine in plant classification?

Reproductive morphology focuses on the structure and form of inflorescences, flowers, and their parts, such as calyx, corolla, stamens, and carpals.

How are anatomical characters typically used in plant classification?

Anatomical characters are often used in addition to other characters and are useful in proving that taxa are not related or in determining the correct position of deviating taxa.

In anatomical studies, what type of differences are of greater value: qualitative or quantitative?

Qualitative differences, such as the structure of hairs, are often of greater value than quantitative differences, such as the number of hairs, in anatomical studies.

What are the three basic aspects studied in cytology?

The three basic things we examine when looking at cytology are the chromosome number, the chromosome structure, and the chromosome behavior.

What is polyploidy and how does it affect plants?

Polyploidy is the doubling of chromosomes and it promotes speciation, or the formation of new species in plants.

Why are breeding systems important in taxonomy?

Breeding systems are of taxonomic value because the degree of interbreeding determines the variation pattern of a taxon, helping to define species.

What characterizes inbreeding plants?

Inbreeders produce seed predominantly through self-fertilization, leading to uniform individuals within a population but lots of variation between populations.

What are some mechanisms that promote outbreeding in plants?

Mechanisms that promote outbreeding include dioeciousness (different sexes on different plants), protandry (anthers open before style is receptive), and self-incompatibility.

What is a taxonomic hybrid?

A taxonomic hybrid is the product of a crossing between two different taxa, and can often be identified as a phonetic intermediate between the two putative parents.

What are three reasons for the rapid development of chemotaxonomy?

Three reasons for the rapid development of chemotaxonomy are the development of new techniques, a realization of large chemical variation in plants, and a tendency to use as many characters as possible in classification.

What is the difference between primary and secondary metabolites?

Primary metabolites are involved in the vital functions of plants and are universally present, while secondary metabolites accumulate in cells and are not involved in vital functions.

What are semantides?

Semantides are information carrying molecules, including DNA (primary), RNA (secondary), and proteins (tertiary).

Why do we not yet have a perfect classification system?

Though many postulated it would determine a perfect classification system, complicated plant breeding systems means that cementides are used in combination with morphology to produce classification.