Biology Exam --> Diversity of Life

structural diversity

a type of biological diversity that is exhibited in the variety of structural forms in living things, from internal cell structure to body morphology

prokaryote

A unicellular organism that lacks a nucleus and membrane bound organelles --\> smaller

Eukaryote

A cell that contains a nucleus and membrane-bound organelles --\> larger and more complex

What are the 3 domains

1. Prokaryote: Bacteria
2. Prokaryote: Archaebacteria
3. Eukaryotes

What are the 6 kingdoms

1. Plants
2. Animals
3. Protists
4. Fungi
5. Archaebacteria
6. Eubacteria

Dichotomous key (not sure we need this)

an identification tool consisting of a series of two-part choices that lead the user to a correct identification

autotroph

an organism that creates its own food and energy --\> photosynthesis

Heterotroph

An organism that cannot make its own food and gets its nutrients and energy from consuming other organisms

Plantae Kingdom Characteristics (with example)

eukaryote, multicellular, autotrophs, sexual, and cell wall is made up of cellulose. Ex. Maple tree

Protista Kingdom Characteristics (with example)

Eukaryote, uni and multicellular, autotrophs, heterotrophs, asexual, usually no cell wall, if cell wall it's made out of cellulose. Ex. Amoeba

Fungi Kingdom Characteristics (with example)

Eukaryote, mostly multicellular, heterotrophs, sexual, cell wall out of chitin. Ex. mushroom

Animalia Kingdom General Characteristics (with example)

Eukaryote, multicellular, heterotrophs, sexual, no cell walls. Ex. Rabbits

Bacteria Kingdom Characteristics (with example)

Prokaryote, unicellular, autotrophs and heterotrophs, asexual, cell wall made out of peptidoglycan. Ex. Staphylococcus

Archaea Kingdom Characteristics (with example)

Prokaryote, unicellular, autotrophs and heterotrophs, asexual, cell wall not made out of peptidoglycan, usually no cell wall. Ex. Sulfolobus archaea

How can you classify bacteria?

Their shapes and groupings, but also the structure of their cell walls.

3 Basic forms of bacteria

1. Spherical
2. Rod
3. Spiral

4 Bacteria Groupings

1. Mono - bacterial cells are singular and un-attached.
2. Diplo - 2 cells attached
3. Strepto - cells arrange themselves in a chain
4. Staphylo - cells clustered as grapes

Gram positive

Bacteria that have a cell inner cell membrane and outer, thick cell wall made of peptidoglycan.

gram negative

Bacteria that have an inner cell membrane, a thinner cell wall made of peptidoglycan and an additional outer protective membrane. These bacteria are more resistant to antibiotics and are therefore dangerous as pathogens

Bacteria diagram

Capsule

A gelatinous material that completely covers the cell. It's protective function is that it makes ingesting the bacteria unpleasant to predators.

Cell wall

made of peptidoglycan which prevents too much water absorption and prevent the cell from bursting

Cell membrane

the semipermeable membrane surrounding the cytoplasm of a cell. It synthesizes new cell wall and capsule material, is responsible for transport in and out of cell, and controls cell respiration and photosynthesis activity

pilus (pili)

hairlike extensions used for adhesion (cell-sticking). They can also be used to exchange DNA in conjugation if they are sex pili

flagella

long tails that are used for movement

Mesosome

an extension of the membrane that DNA attaches to during binary fission

Hereditary material (chromosome and plasmids)

DNA coiled into a circular molecule ( chromosome). There is only one such molecule. Plasmids are small circles of DNA in the cytoplasm of the bacterium that contain other genes that are not found on the chromosome.

Ribosomes

used for protein synthesis --\> smaller than those in eukaryotic cells

coccus

A spherical micro-organism

bacillus

Rod shaped micro-organism

Methanogenesis

unique metabolism to Archaea which is a biological (or chemical) process that produces methane as a by-product

Cyanobacteria

Bacteria that can carry out photosynthesis

Bacteria habitats

Most are mesophiles, meaning they occupy environments with moderate conditions. Some are extremophilic. They can live in environments with or without oxygen.

Archaea habitats (with examples)

They are extremophiles, meaning they occupy extreme environments. ex. deep sea vents, hot springs, volcanic crater lakes, mine drainage lakes, salt lakes, inland seas, cattle guts, landfill sites, sediments of swamps

binary fission

asexual form of reproduction used by most prokaryotes (and some eukaryotic organelles) in which a cell divides into 2 genetically identical cells (or organelles)

conjugate

a process in which there is a transfer of genetic material involving 2 cells

endospore

dormant bacterial cell able to survive for long periods of time during extreme environmental conditions. Not yet found in archaea.

virus

a structure that contains strands of DNA or RNA surrounded by a protective protein coat; it cannot live independently outside of cells. Viruses do not meet all criteria, so they aren't living organisms. Must invade cells and use host cell's machinery for survival and reproduction. They aren't cellular, so no cytoplasm, membrane-bound organelles, or cell membranes. Harmful.

capsid

outer protein layer that surrounds the genetic material of a virus

replication

the fundamental process of all cells, in which the genetic material is copied before the cell reproduces

lytic cycle

the replication process in viruses in which the virus's genetic material uses the copying machinery of the host cell to make new viruses

lysogenic cycle

the replication process in viruses, in which the viral DNA enters the host cell's chromosome; it may remain dormant and later activate and instruct the host cell to produce more viruses

lytic cycle diagram

Step 1 of Lytic Cycle

Virus attaches itself to a bacterial cell. The virus is a very simple structure, composed of a protein capsid, nucleic acid, and a tail section.

Step 2 of Lytic Cycle

The virus enters the cell and injects its nucleic acid. The nucleic acid makes viral proteins with the help of the cell's ribosomes. The proteins sever the DNA of the cell.

Step 3 of Lytic Cycle

The virus's worthless capsid and tail separate from the cell and disintegrate. The viral nucleic acid takes control within the cell and drives the synthesis of additional virus proteins and nucleic acid

Step 4 of Lytic Cycle

Virus proteins and nucleic acids come together to form new viruses.

Step 5 of Lytic Cycle

The viral nucleic acid produces proteins that induce the host bacterial cell to lyse (burst), resulting in the cell's death. Many new viruses are now able to infect other cells.

Animal Characteristics

1. They are eukaryotic, multicellular, and don't have cell walls
2. They're heterotrophs that usually ingest and then digest food
3. They're usually mobile, or can move, in at least one stage of life
4. They reproduce sexually and produce embryos that undergo stages of development

invertebrate

An animal without a backbone --\> 95% of this kingdom

vertibrate

An animal with an internal skeleton and a backbone

Other characteristics to classify animals

1. levels of organization
2. number of body layers
3. symmetry and body plans
4. body cavity
5. segmentation
6. movement
7. reproduction

layers of organization

Animals are classified on the basis of differences in structure, tissues, and organ systems. Animals have varying levels of structure and complexity in organ systems like the digestive, nervous, respiratory, and circulatory systems

number of body layers

all animals except sponges and those in Phylum Cnidaria (corals, hydras, jellyfish, anemones) have 3 layers of cells. These layers are the ectoderm (outer), mesoderm (middle), and endoderm (inner). These layers develop early on in the early stages of growth in embryos. This development helps sort cells into an arrangement that produces specialized tissues and organs in the adult animals. In humans, ectoderm produces skin, nervous tissue, and some sense organs. The mesoderm produces muscles, blood, kidneys, and reproductive organs. The endoderm produces lungs, liver, pancreas, bladder, and stomach lining.

Symmetry and body plans (with examples)

Different arrangements of cells, tissues, and organs lead to different body plans. Some have asymmetrical body plans, meaning their body shapes are irregular (ex. sponges). some have radial symmetry, meaning they can be divided along any place parallel with the body axis. Dissected from the top, every side is symmetrical (circular) (ex. corals and jellyfish). Some have bilateral symmetry and can be divided into two mirror halves only along one place through the central axis. Each side is symmetrical. (ex. worms, insects, and vertebrates like turtles or humans).

body cavities

Some animals have digestive tracts and other organs suspended in a fluid-filled body cavity called the coelom (space for the development and suspension of organs and systems). Animals with coeloms (ex. worms, molluscs, insects, and vertebrates) are called coelomates. Animals without are called acoelomates (ex. jellyfish, flat worms, corals).

Why are coeloms important

For animals, this gives their muscles a structure to brace against, allowing them to move and respond quicker. Also allows for development of more complex organ systems. Ex. digestive tract can grow longer than the body cause it can bend and fold back on itself within coelom. In more complex animals (vertebrates), the coelom is subdivided into separate cavities around the heart and lungs and digestive tract.

segmentation

Some animals like worms and scorpions are segmented, meaning the body is divided into repetitive sections or segments. One advantage is that if a segment is damaged, the others can continue functioning properly. Mobility is also more effective because segments move independently which allows for more complex patterns of movement.

movement

the evolution of nerve and muscle tissue that allows the development of complex and fast movement. Some animals (sponges and sea anemones) are sessile, or stationary as adults. This means they're attached to one place. Sessile animals have a body form that can move during juvenile stages of development.

reproduction

Most animals reproduce sexually with gametic reproduction. External fertilization is when gametes combine outside the body. Zygotes are produced by either external or internal fertilization. External is common for aquatic animals. Internal occurs when egg and sperm meet inside female body. Some animals can reproduce asexually, such as some aphids. They alternate between sexual and asexual modes depending on tough conditions.

Sponges (porifera)

no distinct tissues or organs, have specialized cells, no symmetry, sessile (as adults)

Cnidarians (with examples)

Tissues but no organs, radial symmetry, predators (tentacles surround gut opening, extracellular digestion --\> releases enzymes into gut cavity and absorbs by cells lining guts). Ex. jellyfish, hydra, sea anemone, coral

polyp

tube-shaped, sessile body form of cnidarians

medusa

umbrella-shaped, free-swimming body form of cnidarians

Platyhelminthes

Flatworms --> tapeworm, planaria. They're mostly parasitic, bilaterally symmetrical, first animal with cephalization (development of head, brain, sense organs), top end and posterior end, concentration of sense organs in head, increase speciation in body plan

Nematoda

roundworms, bilaterally symmetrical, body cavity (pseudocoelum \= simple body cavity), digestive system (tube running through length of body), many are parasitic (hookworm)

mollusca

mollusks (slugs, snails, clams, squid), bilaterally symmetrical, soft bodies (mostly protected by hard shells), true coelom (increases complexity and speciation of internal organs)

annelida

segmented worms (earthworms, leeches), segments (increase mobility, redundancy in body sections), bilaterally symmetrical, true coelom

arthropoda

(spiders, insects, crustaceans), most successful animal phylum, bilaterally symmetrical, segmented (specialized segments, allows jointed appendages), exoskeleton (chitin + protein)

arthropod groups

arachnids (8 legs, 2 body parts), crustaceans (gills), insects (6 legs, 3 body parts)

echinodermata

(starfish, sea urchins, sea cucumber), radially symmetrical as adults, spiny endoskeleton

Chordata

Vertebrates (fish, amphibians, reptiles, birds, mammals), internal bony skeletons (backbone encasing spinal column, skull-encase brain)

Fish (with examples)

bony and cartilaginous skeleton, jaws and paired appendages (fins), scales, gills for gas exchange, two-chambered heart (single loop blood circulation), ectotherms, external fertilization (external development in aquatic egg) ex. salmon, trout, sharks

amphibian (with examples)

legs (tetrapods), moist skin, lungs and diffusion through skin for gas exchange, three chambered heart (veins from lungs back to heart), ectotherms, external fertilization (external development in aquatic egg, metamorphosis (tadpole to adult). ex. frogs, salamanders, toads

Reptiles (with examples)

dry skin, scales, armour, lungs for gas exchange, three-chambered heart, ectotherms, internal fertilization (external development in amniotic egg). ex. dinosaurs, turtles, lizards, snakes, alligators, crocodiles

Birds (aves) (with examples)

feathers and wings, thin, hollow bone (flight skeleton), very efficient lungs and airsacs, four-chambered heart, endotherms, internal fertilization (external development in amniotic egg). ex. finches, hawks, ostrich, turkeys

Mammals (with examples)

hair, specialized teeth, lungs, diaphragm, four-chambered hearts, endotherms, internal fertilization (internal development in uterus, nourishment through placenta, birth live young, mammary glands make milk). ex. whales, ferret, elephants, bats, mice, humans

Mammal subgroups

1. Monotreme
2. Marsupial
3. Placental

monotreme (with examples)

Egg laying mammals, lack placenta and true nipples. ex. platypus, echidna

marsupials (with examples)

pouched mammals, offspring feed from nipples in pouch, short-lived placenta. ex. koala, kangaroo, opossum

placental (with examples)

true placenta (nutrient and waste filter). Ex. shrews, bats, whales, humans

animal phylogenetic tree