bio exam 3

Cleavage

Process where the zygote undergoes rapid mitotic divisions with no significant growth

Blastula

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

Gastrulation

Cells migrating toward the interior of the blastula

Gastrula

Embryo that has different layers of embryonic tissue

Body Plan

A set of morphological and developmental traits, integrated into a living animal

Radial Symmetry

Symmetry that has several radii

Bilateral Symmetry

Two sided symmetry

Tissues

Collections of specialized cells isolated from other tissues by membranous layers

Ectoderm

Germ layer covering the embryo's surface

Endoderm

The innermost germ layer

Mesoderm

Layer in between the ectoderm and endoderm

Diploblastic Animals

Have ectoderm and endoderm

Triploblastic Animals

Have ectoderm, endoderm, and mesoderm

Coelomates

Animals that possess a true coelom, a body cavity derived from mesoderm. They also have a well organized organ system.

Pseudocoelomates

Animals that possess a pseudocoelom, a body cavity that is derived from mesoderm and endoderm. They have organs that are loosely held together.

Acoelomates

Animals that lack a body cavity.

Invertebrates

Animals that lack a backbone and account for 95% of known animals species.

Sponges

\-Sedentary animals that live in both fresh and marine waters

\-Lack true tissues and organs

\-Suspension Feeders: capturing food particles suspended in the water that pass through their body

\-Hermaphrodites: function as both male and female.

Tapeworms

\-Parasites of vertebrates

\-Lack a digestive system

\-Sometimes ingested by consuming undercooked food

\-Absorb nutrients from host's intestine

\-Fertilized eggs produced by sexual reproduction leave the host's body in feces

Rotifers

\-Tiny animals that inhabit fresh water, ocean, and damp soil

\-Smaller than may protists but truly multicellular with specialized organ systems

\-Have an alimentary canal, a digestive tube with a separate mouth and anus that lies within a fluid filled pseudocoelom

\-Reproduce by parthenogenesis, an asexual reproduction in which females produce offspring from unfertilized eggs

\-Some species lack males entirely

Insects

\-Live in almost every terrestrial habitat and in fresh water

\-Internal anatomy includes several complex organ systems

\-Flight is one key to their success

\-Beneficial as pollinators, or are harmful as carriers of disease or pests of crops

Complete Metamorphosis

Insects that have larval stages and then enter an inactive state called pupa and then emerge as adults. Ex: Butterfly

Incomplete Metamorphosis

Young, called nymphs, resemble adults but are smaller and lack adult features such as genitals and wings

Vertebrates

Animals that have a series of bones forming a backbone

Derived Characters of Vertebrates

\-Vertebrae enclosing a spinal cord

\-An elaborate skull

\-Fin rays, in the aquatic forms

Gnathostomes

Jawed vertebrates

Characters Common to Gnathostomes

\-An additional duplication of Hox genes

\-An enlarged forebrain associated with enhanced smell and vision

\-In aquatic gnathostomes, the lateral line system, which is sensitive to vibrations

Oviparous

Eggs hatch outside of the mother's body

Ovoviviparous

The embryo develops within the uterus and is nourished by the egg yolk

Viviparous

The embryo develops within the uterus and is nourished through a yolk sac placenta from the mother's blood

Tetrapods

Gnathostomes that have limbs

Derived Characters of Tetrapods

\-Four limbs, and feet with digits

\-Ears for detecting airborne sounds

Amphibians

Referring to the metamorphosis of an aquatic larva into a terrestrial adult

Amniotes

Group of tetrapods whose living members are the reptiles, including birds and mammals

Amniotic Egg

Contains membranes that protect the embryo

Reptiles

-Include lizards, snakes, turtles, crocodiles, birds, and extinct dinosaurs

-Ectothermic

\-Lay shelled eggs on land

Birds

Endothermic

Derived Characters of Birds

\-Flight

\-Keratin feathers

\-Lack of a urinary bladder

\-One ovary in females

\-Small gonads

\-Loss of teeth

Derived Characters of Mammals

\-Mammary glands, which produce milk

\-Hair

\-Larger brain than other vertebrates of equivalent size

\-Differentiated teeth

\-Three middle ear bones

Three Living Lineages of Mammals that Emerged

1. Monotremes
2. Marsupials
3. Eutherians

Monotremes

Small group of egg laying mammals

Marsupials

Embryo develops within a placenta in the mother's uterus and they give birth to undeveloped young

Eutherians

\-Same as marsupials but infants here complete their embryonic development within the uterus and are fully developed

* PRimates

Derived Characters of Primates

\-Large brain and short jaws

\-Forward looking eyes close together on the face, providing depth perception

\-Complex social behavior and parental care

\-Fully opposable thumb in monkeys and apes

\-Most primates have hands and feet adapted for grasping

Derived Characters of Humans

\-Upright posture and bipedal locomotion

\-Larger brains

\-Language capabilities and symbolic thought

\-The manufacture and use of complex tools

\-Shortened jaw

\-Shorter digestive tract

Paleoanthropology

The study of human origins

Hominins

\-More closely related to humans than to chimpanzees

\-Not chimpanzees

\-Do not imagine human evolution as a ladder leading directly to homo sapiens

Hominin Lineage

-Homo ergaster: First fully bipedal large brained hominid

-Homo sapiens: All living humans are descended from these

Interstitial Fluid

Fills the space between cells and allows for the movement of material into and out of cells

Tissues

Specialized cells that are organized to have different functions

Epithelial Tissue

\-Covers the outside of the body and lines the organs and cavities within the body

\-Contains closely joined cells

\-Cuboidal, Columnar, or Squamous

\-Simple, Stratified, or Pseudostratified

\-Helps in protection, secretion, and selective absorption

Connective Tissue

\-Binds and supports other tissues

\-Contains sparsely packed cells scattered throughout an extracellular matrix

-3 Types of Connective Tissue Fiber:

\-Collagenous Fibers

\-Elastic Fibers

\-Reticular Fibers

Collagenous Fibers

Provide strength and flexibility

Elastic Fibers

Stretch and snap back to their original length

Reticular Fibers

Join connective tissue to adjacent tissues

Six Major Types of Connective Tissue

1. Loose CT
2. Cartilage
3. Fibrous CT
4. Adipose
5. Blood
6. Bone

Loose CT

Binds epithelia to underlying tissues and holds organs in place

Cartilage

Strong and flexible support material

Fibrous CT

Found in tendons

Tendons

Attach muscle to bone

Ligaments

Connect bones at joints

Adipose Tissue

Stores fat for insulation and fuel

Blood

Composed of blood cells and cell fragments in blood plasma

Bone

Mineralized and forms the skeleton

Muscle Tissue

Consists of long cells called muscle fibers, which contract in response to nerve signals

Skeletal Muscle

\-Striated

\-Responsible for voluntary movement

Smooth Muscle

Involuntary body activities

Cardiac Muscle

Contraction of the heart

Nervous Tissue

Senses stimuli and transmits signals throughout the animal

Neurons

Nerve cells that transmit nerve impulses

Glial Cells

Help nourish, insulate, and replenish neurons

Endocrine System

Transmits chemical signals called hormones though the body via blood

Nervous System

Transmits info between specific location

Regulator

Uses internal control mechanisms to moderate internal change in the face of external environmental fluctuation

Conformer

Allows its internal condition to vary with certain external changes

Homeostasis

Management of internal environment

Negative Feedback

Regulates homeostasis by returning a variable to either a normal range or a set point

Acclimatization

The process where homeostasis can adjust to changes in an external environment

Thermoregulation

Process by which animals maintain an internal temperature within a tolerable range

Endothermic Animals

Generate heath by metabolism and is more energetically expensive. Ex: Birds and mammals

Ectothermic Animals

Gain heath from external sources. Ex: most invertebrates, fishes, amphibians, and non avian reptiles

Body System used in Thermoregulation

Integumentary system: skin, hair, and nails

5 General Adaptations to Help Animals Thermoregulate

1. Insulation
2. Cooling by Evaporative Heat
3. Behavioral Responses
4. Adjusting Metabolic Heat Production
5. Circulatory Adaptations

Insulation

Skin, feathers, fur and blubber reduce heat flow between an animal and its environment

Cooling by Evaporative Heat

Many types of animals lose heat through evaporation of water in sweat.

Behavioral Responses

Postures that minimize or maximize heat absorption

Adjusting Metabolic Heat Production

Some animals adjust their rate of metabolic heat production by increasing their muscle activity such as moving or shivering

Circulatory Adaptations

1. Vasodilation
2. Vasoconstriction

Vasodilation

Blood flow in the skin increases, facilitating heat loss

Vasoconstriction

Blood flow to the skin decreases, lowering heat loss

Thermoregulation Control

Controlled by hypothalamus

Bioenergetics

Overall flow and transformation of energy in an animal

Biosynthesis

Includes body growth and repair, and synthesis of storage material such as fat

Metabolic Rate

The amount of energy that an animal uses in a unit of time

Basal Metabolic Rate

The metabolic rate of an ENDOTHERM at rest at a comfortable temperature

Standard Metabolic Rate

The metabolic rate of an ECTOTHERM at rest at a specific temperature

Torpor

Physiological state in which activity is low and metabolism decreases