Powerpoint presentation about systematics: order and taxonomy

1. MODULE 5
PRE-TEST

3. MODULE 5
SYSTEMATICS:
Finding Order and
Relationship

4. classification system;
1. Trace the background of the modern
Lesson Objectives:
to other taxa;
2. Identify the unique/distinctive
characteristics of a specific taxon relative
the relatedness of taxa; and
3. Describe how structure, developmental
characteristics, and relatedness in DNA
sequences are used as evidence to infer
things.
4. Explain how relatedness in the DNA
sequence is used in classifying living

5. Studying the classification of living things based on
similar characteristics is called taxonomy. The term
taxonomy came from the Greek word “taxis” which means
arrangement, and “nomos” which means law, thus
making taxonomy “the law of arrangements.” The orderly
arrangement of organisms into groups is called
systematics.
What is the difference between
taxonomy and systematics?

6. When DNA researches started to flourish, a new
technique in determining relationships among
organisms came about called DNA sequencing. It
started when molecular biologists examined long DNA
strands and found that the more similar the DNA
strands are in two organisms, the more closely related
they are with each other. As new DNA techniques
develop, startling discoveries about how species are
related to one another arise.

7. THE DISCOVERY
In 1953, they concluded that the
DNA molecule appears as a
three-dimensional double helix.
They used X-ray crystallography
to study DNA's structure, which
helped Watson and Crick with
their discovery.
James Watson and
Francis Crick
Rosalind Franklin
and Maurice Wilkins

8. DNA
the general laboratory
technique for determining the
exact sequence of nucleotides,
or bases, in a DNA molecule.
Consists of two nucleotide chains
Each nucleotide consists of a
sugar molecule, a phosphate
group, and a nitrogen-containing
base
DNA sequencing
DNA Double Helix

9. TOXONOMY
“description, identification,
nomenclature, and classification
of organisms”(Simpson, 2006)
Linnaean Classification System
Characteristic
Evolution of History
Branch of Biology that names
and groups organism based on
their :
1.
2.

10. HISTORY
As early as 3000 BC, the Chinese had been classifying plants in order to
catalog medicinal herbs and their uses.
Later, the Greeks and Romans, most notably Aristotle, and his student
Theophrastus, also classified plants and organisms. In his paper, Xu
notes that Theophrastus developed De Historia Plantarum whose
names for genera are still used today. For a long time, their works and
that of others have been the basis for much of the taxonomy all over the
world. These systems of classification were largely based on observable
characteristics and behaviors as seen by scientists at the time.

11. Around the 16th century, the collection of specimens became part
of the growing sciences, and the classification of organisms was
done not merely for practical reasons like medicine but purely for
taxonomic reasons (Xu et al., 2020).
By the 17th century, Carolus Linnaeus published Systema
Plantarum and System Naturae (Xu et al., 2020), which eventually
led to the development of a system of nomenclature using phrase
names that later evolved into the binomial nomenclature scientists
all over the world now use.

12. a two-word scientific naming system developed
by Carolus Linneaus that provides a unique
name for every for living thind.
scientific name is always in italic (or, if hand-
written, underlined), genus capitalized, species
not capitalized.
BINOMIAL
NOMENCLATURE

13. EVOLUTION OF
SPECIES
“All life has been derived from pre-existing life”. Charles Darwin
defines biological evolution as “descent with changes”.
Descent is the transfer of genetic material from parent to offspring.
This transfer over generations results in a modification to the
genetic materials. Evolution may occur through genetic drift or
natural selection, resulting in something speciation.

14. Speciation is the forming of new species from previous
species through evolution (Simpson, 2006).
A species is of course, a group of organisms consisting of
similar individuals capable of exchanging genes or
interbreeding (Campbell & Reece, 2008). Evolution has led to
the creation of diverse species all connected through time
and space by virtue of the process of descent from the
existence of the first living organism.

15. All the diverse characteristics, traits, and genetics in the organisms we
classify today exist because of the series of genetic transfer and
modification known as evolution.
Organisms are arranged
in categories in the order
of increasing specificity:
Linnaean Classification
System

16. HOW ORGANISM ARE GROUP BASED ON PHYSICAL CHARACTERISTIC
A common tool used to infer relatedness in taxa, in
which it refers to the general aspects of biological
form and arrangement of the parts of a plant or an
animal.
For instance, flowering plants are grouped together in
a clade called Angiospermae because scientists have
determined that flowerbearing plants are more closely
related to each other than they are with nonflowering
plants.
Morphology

18. HOW ORGANISM ARE GROUP BASED ON PHYSICAL CHARACTERISTIC
Animals classified under
Mammalia, for instance, are
more closely related to each
other because of their
similarities in embryonic
development that they do not
share with other species
Developmental
Characteristic

19. HOW ORGANISM ARE GROUP BASED ON ON THEIR LINES OF
EVOLUTIONARY DESCENT
The sharing of these traits from a common ancestor to
their descent tells us that species within the same genus
are more closely related than to a species from another
genus.
The shared trait is from that of the recent ancestors;
thus, the higher the level of the taxon, the farther back in
time is the common ancestor.
Evolutionary descent/ Phylogeny

20. HOW ORGANISM ARE GROUP BASED ON CHARACTERISTIC
Anatomical resemblance among the species is generally
reflected in their genes (DNA) and gene product (proteins).
Cytochrome c is a protein located in the mitochondria of
cells involved with cellular respiration. Genes are segments of
DNA that contain codes for a specific protein that functions
in one or more types of cells in a body. The order of amino
acids in a protein is determined by the sequence of bases in
DNA which serves as the blueprint for protein assembly. The
close relationship between two organisms can be
determined by a protein’s amino acid sequence.
Anatomical resemblance

21. DNA is continually
changing through the
process called a mutation.
The slight change in the
DNA and the protein being
built modifies an
organism’s genetic
makeup, which may cause
changes in the physiology
of an organism.
As a result, this mutation is
carried and passed to its
offspring (see Fig. 6)

22. Try this background for online class.
*Please delete this section before downloading.
HOW ORGANISM ARE GROUP BASED IN MOLECULAR INFORMATION:
This is so because evolution
begins at the molecular level
starting with changes in the
DNA that occurs as genes are
transferred from parent to
offspring (Solomon et al.,
2018).
DNA sequences