Compana lab exam 1

based on ppt ni sir monds

Comparative Anatomy

the study of similarities and differences in the anatomy of different species

Comparative Anatomy

to understand how they changed over time to survive better, starting from shared ancestors

Anterior/Ventral

At or near the front of the body

Posterior/Dorsal

At or near the back of the body

Superior/Cranial

Above, Toward the head

Inferior/Caudal

Below, Toward the tail/feet

Medial

Toward central line

Lateral

Away from the central line, toward the side, beside

Superficial

near the body surface

Deep

Further into the body

Proximal

Closer to the point of attachment

Distal

Farther from the point of attachment

Anatomical planes

imaginary, flat surfaces or divisions used to cut through the body

Frontal (coronal) plane

separates the front and back of the body

Transverse (horizontal) plane

separates the upper and lower halves of the body

Sagittal plane

divides the body into left and right

Parasagittal plane

divides the body into unequal left and right halves

Midsagittal plane

divides the body equally into left and right

Oblique plane

any plane that is not perfectly sagittal, frontal, or transverse

Anatomical Axes

imaginary straight lines that pass through the body

Longitudinal axis

runs from head to tail (cranial → caudal)

Transverse (Horizontal) Axis

runs from side to side (left → right)

Sagittal (Dorsoventral) Axis

runs from back to belly (dorsal → ventral)

Longitudinal axis

movement: rotation (e.g., twisting the trunk, turning the head)

Transverse (Horizontal) Axis

movement: flexion and extension (e.g., bending forward, nodding)

Sagittal (Dorsoventral) Axis

movement: abduction and adduction (e.g., raising arms or legs sideways)

Symmetry

refers to the balanced arrangement of body parts on opposite sides of a dividing plane or around a central point

Asymmetry

No pattern in body parts. Examples: Sponges, some corals

Radial Symmetry

Body parts arranged around a central point, like spokes on a wheel or a pizza.
Examples: Jellyfish, sea anemones, adult sea urchins

Bilateral Symmetry

One line splits the body into left and right halves that mirror each other.
Examples: Humans, frogs, insects, cats, dogs, fish

Metamerism or segmentation

the repetition of similar body units (segments) along the longitudinal axis of an animal’s body

Homonomous segmentation

Segments are mostly identical and not specialized (e.g., earthworms/annelids).

Heteronomous segmentation

Segments are specialized for different functions (e.g., insects and other arthropods).

True
-Our vertebral column (spine) is made up of repeating bone units (vertebrae) as well as ribs.  Humans have heteronomous segmentation

True or False
Humans exhibit metamerism or segmentation

Cephalization

putting the brain and sense organs (eyes, nose, ears, antennae) at the front end of the body

Cephalization

evolutionary trend of concentrating sense organs and nervous control at the anterior (head) end of the body

Evolution

The change in the characteristics of a species over several generations and relies on the process of natural selection

Natural selection

Individuals having more useful traits survive better and produce more progeny than individuals with less-favorable traits

Patterns of evolution

recurring trends in the diversification of species, observed across evolutionary history and influenced by factors like genetic variation and environmental pressures

Convergent Evolution

Evolution pattern where organisms that aren't closely related evolve similar traits as they both adapt to similar environments

Divergent Evolution

This evolution pattern occurs when groups from the same common ancestor split into two groupsby a geographic barrier (for instance, a body of water or a migration to a new area), causing each group to develop different traits

Coevolution

Evolution pattern that occurs when two or more species reciprocally affect each other's evolution through the process of natural selection. Each species influences the evolutionary path of the other

Coevolution

Pattern of evolution found in cheetahs and gazelles

Divergent Evolution

Pattern of evolution found in foxes and domestic dogs

Convergent Evolution

Pattern of evolution found in birds, bats, and butterflies

The Tree of Life

A diagram showing the relationship between all the organisms on Earth that have descended from a common ancestor

Phylogeny

the relationship between all the organisms on Earth that have descended from a common ancestor

Phylogenetic tree

diagram that shows relationships backed up with molecular evidence

Cladogram

diagram where relationships are hypothetical

Taxonomy

science of naming, describing, and classifying organisms

to avoid confusion, organize the vast diversity of life, and understand how species are related to each other and to their evolutionary history

Why is there a need to name, describe, and classify organisms?

Carolus Linnaeus

He assigned a unique, two-part scientific name derived from Latin or Greek to each kind of organism (binomial nomenclature)

Binomials are unique to eliminate confusion that often arises from regional differences in common names

When a binomial designation has been published, then it cannot be used for any other species. Why?

Homologous structures

similar physical features in organisms that share a common ancestor, but the features serve completely DIFFERENT functions

Analogous structures

features of different species that are SIMILAR in function but not necessarily in structure and do not derive from a common ancestral feature

Kingdom Animalia

What Kingdom is Chordata from?

Endostyle

•not consistently present in all chordates throughout life
•evolutionary origin may not be exclusiveto chordates
•found in non-vertebrate chordates (filter feeding)

Subphylum Urochordata
Subphylum Cephalochordata
Subphylum Vertebrata

Subphylum under Phylum Chordata

Superclass Agnatha
Superclass Gnathostomata

Superclass under Subphylum Vertebrata

Superclass Agnatha (jawless vertebrates)

Superclass Agnatha (_ _ _ vertebrates)

Superclass Gnathostomata (jawed vertebrates)

Superclass Gnathostomata (_ _ _ vertebrates)

Class Myxini Class Pteromyzontida

Class under Superclass Agnatha

Class Chondrichthyes
Class Osteichthyes
Class Amphibia
Class Reptilia
Class Aves
Class Mammalia

Class under Superclass Gnathosomata

Subclass Actinopterygii
Subclass Sarcopterygii

Subclass under Osteichthyes

Class Myxini
Class Petromyzontida 
Class Chondrichthyes
Class Osteichthyes

Classes that are fishes

Urochordata (Tunicata)

Subphylum of tunicates, sea squirts, salps

Cephalochordata

Subphylum of lancelets (amphioxus)

Vertebrata (Craniata)

Subphylum of vertebrates

Myxini

Class of hagfishes

Petromyzontida

Class of lampreys

Chondrichthyes

Class of cartilaginous fishes (sharks, rays, chimaeras)

Osteichthyes

Class of bony fishes

Actinopterygii

Subclass of ray-finned fishes

Sarcopterygii

Subclass of lobe-finned fishes (includes ancestors of tetrapods)

Amphibia

Class of frogs, salamanders, caecilians

Reptilia

Class of turtles, lizards, snakes, crocodiles, bird

Aves

Class of birds (sometimes included in Reptilia in modern classification)

Mammalia

Class of mammals

Subphylum Urochordata
Subphylum Cephalochordata

Subphylum that lacks a vertebral column/backbone

Cephalochordata

Subphylum _ _ _
-small, filter-feeding has a fish-like body

Vertebrata

Subphylum _ _ _
-highly varied, complex body systems

Urochordata

Subphylum _ _ _
-Notochord and nerve cord are present only in the larval stage

Vertebrata

Subphylum _ _ _
-notochord present in embryo only (becomes vertebrae), nerve cord develops into brain and spinal cord

Urochordata

Subphylum _ _ _
-Sac-like, soft-bodied, filter-feeding through a pharyngeal basket

Cephalochordata

Subphylum _ _ _
-retains the notochord and nerve cord throughout life

Myotomes

a V-shaped muscle blocks for swimming found in Cephalochordata

Atriopore

opening where water exits the body found in Cephalochordata

Oral hood with cirri

finger-like projections that filter food and keep large particles out (Cephalochordata)

Urochordata

Subphylum _ _ _
Chordate traits (notochord, dorsal nerve cord, post-anal tail) are present only in larvae

Urochordata

Undergo retrogressive metamorphosis, where the adult is simpler than the larva

True
-When we're embryos, the embryonic tail usually grows into the
coccyx or the tailbone

True or False: People have tails

Vertebra

Closed circulatory system with a heart

Vertebra

Internal skeleton (cartilage or bone)

Superclass Agnatha

first vertebrates

Superclass Agnatha

do not have true jaws like other fish

Superclass Agnatha

lack scales on their bodies

Class Myxini

Skull only, no true vertebrae

Class Petromyzontida

No slime defense

Class Petromyzontida

Well-developed, functional eyes

Class Myxini

Scavengers, feed on dead/dying fish