Biology 102 Exam 3

Cleavage

Cleavage

When the zygote undergoes rapid mitotic divisions

Blastula

An embryo that has over 100 cells after cleavage has taken place

Gastrulation

When cells migrate to the interior of the blastula

Gastrula

The embryo has different layers of embryonic tissues

Larva

Is a sexually immature stage and is morphologically distinct from the adult

Metamorphosis

The process by which an animal physically develops after brith or hatching

Paleozoic Era

542-251 Million years ago. Called the Cambrian period/explosion. Evolving predator-prey relationships. Rise in atmospheric oxygen. Evolution of the Hot gene complex

Mesozoic Era

251-65.5 Million years ago. Coral reefs emerged. Dinosaurs were the dominant terrestrial vertebrates. First mammals emerged

Cenozoic Era

65.5 Million years ago to the present. Mass extinctions of terrestrial and marine animals (nonflying dinosaurs and marine reptiles). Modern mammals and insects diversified (adaptive radiation)

Cambrian Explosion

The earliest fossil appearance of many major groups of living animals

Body Plan

A set of morphological and developmental traits integrated into an animal (3 types)

Radial Symmetry

An organism can be divided into identical halves by any plane passing through the center of its body

Bilateral Symmetry

An organism can be divided into two equal halves that are mirror images of each other along a central axis

Tissue

A collection of specialized cells isolated from other tissues by membrane layers

Ectoderm

The germ layer covering the embryo’s surface/outermost germ layer

Endoderm

The innermost germ layer

Mesoderm

The middle germ layer

Diploblastic

An animal that has an ectoderm and endoderm

Triploblastic

An animal that has an intervening third layer (mesoderm)

Organogenesis

The process of organs developing from the embryonic germ layers

Coelomate

An animal that possess a true coelom. Organs are well organized in a coelomates

Coelom

A true body cavity and is derived from mesoderm

Pseudocoelomate

An animal that possess a pseudocoelom. Organs are held loosely

Pseudocoelom

A body cavity derived from mesoderm and endoderm

Acoelomates

An organism that lack a body cavity

Invertebrates

An organism that neither possess nor develop a vertebral column/backbone (4 kinds)

Sponges

A sedentary organism that live in both fresh and marine waters that lack tissues and organs. They are suspension feeds. Most are hermaphrodites

Hermaphrodites

An organisms that lacks functions as a male and female

Tapeworm

An organism that are parasites of vertebrates and lack a digestive system and absorb nutrients from the host’s intestine

Rotifers

A tiny organism that inhabits fresh water, ocean, and damp soil. They have an alimentary canal. They produce by parthenogenesis. Some species lack a male sex

Alimentary Canal

A digestive tube with a mouth and anus that lies within a fluid-filled pseudocoelom

Parthenogenesis

When females produce offspring from unfertilized eggs

Insects

Are the organism with the most amount of species. They live in almost every terrestrial habitat and in fresh water. They have several complex organ systems.They may undergo metamorphosis

Metamorphosis

The process by which an animal physically develops after birth or hatching, involving a relatively abrupt change in animal’s body structure (2 types)

Complete Metamorphosis

Has 4 stages: egg, larva, pupa, adult

Complete Metamorphosis Examples

Beetles, bees, ants, butterflies, moths, fleas, mosquitoes

Incomplete Metaorphosis

Has 3 stages: egg, nymph, adult

Nymph

A young organism that resemble adults but are smaller and lack adult features

Incomplete Metamorphosis Examples

Grasshoppers, cockroaches, termites, praying mantis, crickets, lice

Vertebrates

An organism with a backbone

Shared qualities of vertebrates:

1. A backbone enclosing a spinal cord

2. An elaborate skull

Gnathostones

A vertebrate with jaws

Shared qualities of gnathostomes:

1. Jaws

2. An additional duplication of Hox genes

3. An enlarged forebrain associated with enhanced smell and vision

4. A lateral line system that is sensitive to vibrations (aquatic)

Tetrapods

A vertebrate with limbs

Shared qualities of tetrapods:

1. 4 limbs and feet with digits

2. Ears for detecting airborne sounds

Example of a tetrapod:

Amphibian

Amphibian

An organism that starts life as an aquatic larva and then turns into a terrestrial adult

Amniotes

A group of tetrapods that have a terrestrially adapted egg and are reptiles and mammals

Amniotic Egg

An egg that contains membranes that protect the embryo on a terrestrial ecosystem

Example of an amniote:

Reptile

Reptile

An amniote that has scales on their skin that create waterproof barrier and lay their amniotic eggs on land

Amnion

The innermost membrane of amniotic eggs and it encloses the embryo

Amniotic Fluid

A fluid that surrounds the fetus and protects it from heat and physical injury

Ectothermic

A type of organism that absorbs external heat as the main source of body heat (birds and mammals)

Endothermic

A type of organism that is capable of keeping the body warm from within, through matabolism (most invertebrates)

Adaptations of birds that enabled flight:

1. Wings with certain feathers

2. Lack of urinary bladder

3. Females with one ovary

4. Small gonads and loss of teeth

The body plan that categorizes animals:

1. Symmetry

2. Tissues

3. Body Cavities

Mammals

A vertebrate characterized by the presence of derived characters

Derived characters that mammals have:

1. Mammary glands that produce milk

2. Hair

3. A larger brain than other vertebrates of equivalent size

4. Differentiated teeth

5. 3 middles ear bones

Kinds of teeth:

1. Incisors

2. Canines

3. Premolars

4. Molars

Kinds of ear bones:

1. Malleus

2. Incus

3. Stapes

Monotremes

A small group of egg-laying mammals that have a cloaca

Cloaca

A single common urinary, defecatory, and reproductive duct

Example of monotremes:

Platypus

Marsupials

A mammal that gives brith to undeveloped young

Marsupium

A maternal pouch which completes embryonic development for young marsupials

Example of marsupial:

Kangaroos

Eutherians (Placentals)

A mammal that give brith to infants that completed their embryonic development within the uterus and are fully developed

Example of eutherian:

Humans

Derived characters of primates:

1. A large brain and short jaws

2. Forward looking eyes close together providing deep perception

3. Complex social behavior and parental care

4. A fully opposable thumb for grasping

Shared derived characters that distinguish humans from apes:

1. Upright posture and bipedal locomotion

2. Larger brains, language capabilities, and symbolic thought

3. The manufacture and use of complex tools

4. Shortened jaw and shorter digestive tract

Paleoanthropology

The study of human origins

Hominins

An organism that is more closely related to humans than to chimpanzees (6-7 million years ago)

Australopiths

A group of hominins living between 4-2 million years ago that has the oldest evidence of tool use. They didn’t fully master walking long distances on 2 legs

Homo ergaster

A group of hominins that fully mastered walking long distances on 2 legs and showed a decrease in sexual dimorphism

Homo erectus

A group of hominins that originated in Africa about 1.8 million years ago and was the first hominin to leave Africa

Neanderthals

An organism that were closely related to modern humans (99.7% of DNA) and lived in Europe and Asia. They were thick-boned with a larger brain than humans. They had a low surface to volume ratio with shorter legs and a bigger body

Homo sapiens

An organism that appeared in Africa about 200,000 years ago and were the first group to show evidence of symbolic and sophisticated thought. The FOXP2 gene gave them language capabilities

FOXP2 gene

A gene that is essential for human language and underwent intense natural selection over the last 200,000 years

Anatomy

The study of the structure of body parts and their relationship to one another

Physiology

The study of the function of body parts and how they work to carry out life-sustaining activities

Interstitial Fluid

A fluid that fills the space between cells and allows for the movement of material into and out of cells

Necessary life functions:

1. Maintaining boundaries

2. Movement

3. Responsiveness

4. Metabolism

5. Digestion

6. Excretion

7. Reproduction

8. Growth

Maintaining Boundaries

The separation between internal and external environments. Plasma membrane separates cells. Skin separates the organism from the environment

Movement

The muscular system allows movement

Responsiveness

The ability to sense and respond to stimuli like a withdrawal reflex that prevents injury

Metabolism

The chemical reaction that occurs in body cells. The sum of all catabolism and anabolism

Digestion

The breakdown of ingested food followed by absorption into blood

Excretion

The removal of wastes from metabolism and digestion. Urea, carbon dioxide, feces

Reproduction

(Cellular level) The division of cells for growth and/or repair. (Organismal level) The production of offspring

Growth

The increase in size of a body part of an organism

Types of tissues:

1. Epithelial

2. Connective

3. Muscle

4. Nervous

Epithelial Tissue

The tissue that covers the outside of the body and lines the organs and cavities within the body and helps in the protection, secretion, and selective absorption

Shape of epithelial cells:

1. Cuboidal

2. Columnar

3. Squamous

Arrangement of epithelial cells:

1. Simple (single cell layer)

2. Stratified (multiple tiers of cells)

3. Pseudostratified (single layer of cells of varying length)

Connective Tissue

The tissue that binds and supports other tissues

Types of connective tissue fiber:

1. Collagenous fiber

2. Elastic fiber

3. Reticular fiber

Collagenous Fiber

A type of connective tissue fiber that provides strength and flexibility

Elastic Fiber

A type of connective tissue fiber that stretches and snaps back to their original length

Reticular Fibers

A type of connective tissue fiber that join connective tissue to adjacent tissues