BZ 214 Exam One

Extinct

A species that is no longer alive

Extant

Species that is currently alive

How are mass extinctions connected to species diversity?

Mass extinctions open up niches that result in species diversifying to fill those niches

What era did vertebrates first appear?

Paleozoic

What period did vertebrates first appear?

Ordovician

What is a vertebrate?

An organism that has a vertebrate

Monophyletic

A common ancestor and all of its descendants

Paraphyletic

A common ancestor and some of its descendants

Polyphyletic

Descendants and no common ancestor

Outgroup

A reference group that is less closely related to the group under study than the members of the ingroup are to each other

Shared derived characteristics

A derived (more recently evolved) character shared by two or more taxa that was inherited by a common ancestor

Shared ancestral characteristics

Ancestral (Older) character shared by two or more taxa that was inherited by a common ancestor

Characters that define chordates

* Dorsal nerve chord
* An endostyle or pharyngeal gill slits
* A dorsal neural tube
* A muscular post-anal tail

True or false: Chordates must possess all the defining traits at the same time at some point in their development

True

Homolgous

Traits that are similar and share evolutionary origin

Analogous

Traits that are similar and do not share evolutionary origin

Convergent evolution

Occurs when species occupy similar ecological niches and adapt in similar ways due to similar selective pressures

Parallel evolution

Occurs when independent species acquire similar characteristics while evolving together in the same time and space

True or False: Because cartilage is less mineralized than bone it is weaker

False

Skeletal systems

Used for support, movement, protection, and storage of calcium and phosphate

Two main parts of the skeleton

Axial and appendicular

Six types of mineralized tissues

* Cartilage
* Bone
* Dentin
* Enamel
* Enameloid
* Cementum

Mineralized tissues related to teeth

* Dentin
* Enamel
* Enameloid
* Cementum

Cartilage

Less mineralized than bone, gains its strength from amount of times it wraps around itself

Bone

Divided into dermal and endocondral

Dermal bone

Flat bones, usually found within skin without cartilaginous precursor

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Endochondral bone

Bones of the appendicular skeleton, usually first formed as cartilage

* Found in the long bones

Earliest type of vertebrate bone

Dermal bone - Found in ostracoderms

True or False: Most skull bones are endochondral

False - Most skull bones are dermal

Muscle functions

Movement; either of the body itself or organs within the body

Three types of muscle

Skeletal, smooth muscles, and cardiac muscles

Skeletal or striated muscles

Muscles that move the body

More endurance related organisms will have ______

Red skeletal muscles

Less endurance related organisms will have _____

White skeletal muscles

Smooth muscles

Line organs of the body

Cardiac msucles

Muscles of the heart, combination of smooth and striated muscles, unique

Digestive system

Obtain and distribute nutrients throughout the body

True or False: Only small particles can be absorbed into the body

True

True or False: Digestive systems are the same across organisms

False - Digestive systems vary greatly amongst organisms to account for the wide range of diets

Parasitic digestive systems

Generally have reduced digestive systems (Lampreys)

Herbivorous digestive systems

Generally have more complex digestive systems (Ruminants)

Respiratory systems

Functions to allow exchange of gases between body and environment

How do all respiratory surfaces work?

By diffusion

What physical characteristics do respiratory surfaces need?

They need to be moist and thin - Allows the diffusion to take place

Circulatory system

Functions to transport gases (O2 and CO2), nutrients, hormones, and heat throughout the body.

Capillaries

The site of gas exchange

How small are capillaries?

Capillaries are one cell thick (This is the same across all vertebrates)

What circulatory system do vertebrate have?

Closed circulatory system

How is blood distributed throughout the body?

Blood is pumped through the body by a 2-4 chambered heart.

What other use does the circulatory system have?

Certain cells within it also participate immunological functions in response to foreign substances or pathogens

Execratory System

functions to remove metabolic waste (primarily urea and derivatives), maintain water balance, and regulate various ions

Primary organ in execratory systems

The kidney in tetrapods; in aquatic organisms, gills and skin also play a large role.

Reproductive systems

The gametes: Sperm and eggs

Sperm

Low in energy to make

Eggs

High in energy to make

Sexual dimorphism

Females are generally larger than males as eggs require more energy

Oviparous

Organism lays eggs

Viviparous

Organism bears live young

Is sex determined by only X and Y chromosomes?

No, sex is determined by a number of factors

Sensory systems

Functions to integrate information and response throughout the body; senses events in external environment

The two parts of the sensory system

Central nervous system

Peripheral nervous system

Vertebrate brain parts

Forebrain, hindbrain, midbrain

Midbrain

Coordinates reflex, responses to sight and sounds

Hindbrain

Reflex control of respiration, blood circulation, other basic tasks

Hindbrain in complex vertebrates

Coordination of sensory input, motor dexterity, and possibly mental dexterity

Forebrain

Receives, integrates sensory information from nose, eyes, ears

Land dwelling vertebrates

Contains highest integrating centers

Sharks and sensory systems

High integrating centers for chemical queues

Forebrain has two main parts

Diencephalon and telencephalon

Diencephalon

Pituitary gland, hypothalamus, and pineal organ

Telencephalon

Develops in association with olfaction and other sensory modalities

* cerebrum of higher vertebrates

Midbrain and Vision

Varies amongst vertebrates - Mammals rely heavily on color

Hindbrain parts

Myelencephalon and metencephalon

Metencephalon

Regulates motor activity

* Develops the cerebellum in jawed vertebrates

Myelencephalon

Regulates respiration, balance, and orientation

Myelencephalon in land-dwelling vertebrates

More developed as it requires higher motor skills to maneuver on land than it does in the water

Endocrine system

Functions in regulating and controlling various functions via chemicals

Endocrine and the Nervous system

Regulated by the nervous system and regulates the nervous system

True or False: Not one system in the body works independently

True! Every system within the body works together to maintain the organisms

* If one part is not working, it can cause issues throughout the entire body, similar to the internal workings of a computer

What are hormones?

Hormones are chemical messengers

Where do hormones come from?

Hormones are released by the endocrine glands

True or False: Hormones only work when there are receptors for those hormones.

True

What do Hox Genes do?

Hox genes help lay out the basic body forms of many animals

* Set up head-to-tail organization

True or False: Hox genes are only found in animals.

False. Hox genes have been found in both animals AND plants

Hox Genes

A group of transcription factors that regulate other genes

* Found in clusters and expressed collinearly
* Initiates signal cascades to tell genes when to turn on and when to start laying out the body plan

True or False: Hox gene clusters are always the same

True. Hox gene clusters are always the same, although there are different duplications of the clusters that result in different body plans (Example. Cephalization in chordates)

Why don’t all vertebrates look the same if the hox gene clusters are the same?

Key determining factors are

* Concentration
* Location
* Timing
* Target gene specificity

Nervous system

* Neurons
* Myelin sheath
* Axon
* Nerve

Neurons

Individual cells that are the basic unit of the nervous system

Myelin sheath

Fatty insulating coat that surrounds the axon of neurons and serves to increase the conduction velocity of the nerve impulse

True or False: The Myelin sheath is found in all animals

False. The myelin sheath is only found in vertebrates

Axon

The long extension of neurons

Nerve

A collection of axon

Ostracoderms

Earliest defined “Vertebrates”

True or False: The first appearance of bone was in Ostracoderms.

True! Ostracoderms had dermal bone in their head that acted like a helmet for protection

True or False: Ostracoderms had a bony skeleton.

False! Ostracoderms had a cartilaginous skeleton, although they did have some dermal bone in their skull

What does an increase in body plans result in?

An increase in body plans results in an increase of metabolic activity

True or False: In GENERAL, bony fish are more active than cartilaginous fish

True. Although there are some exceptions (such as great white sharks), bony fish are typically more active than cartilaginous fish

What animal group has the highest metabolic rate?

Birds

Conodonts

Some of the earliest vertebrates, only described by tooth-like elements