Exam 1 Flashcards
Phylogeny
-The evolutionary history of a species or group of species
Phylogenetic Tree
-The evolutionary history of a group of organisms represented in a branching diagram
Homology
- Similarly in characteristics resulting from a shared ancestry
- Ex: vertebrates all have bony skeletons
Homoplasy
- A similar characteristic that has evolved independently of two species
- Ex: Fish and whales similar becuz adapted to eater
Convergence
- Also known as convergent evolution
- The evolution of similar features in independent evolutionary lineages
Monophyletic
- Pertaining to a group of taxa that consists of a common ancestor and all of its descendants
- Monophyletic taxon= clade
Polyphyletic
-Pertaining to a group of taxa that includes distantly related organisms but doesn’t include their most recent common ancestor
Synapomorphy
- Recently evolved homology that applies to s subset of phylogeny
- Most recent common ancestor identified by this
Paraphyletic
-An ancestral species, and some, but not all, descendants
Clade
- All descendants of a common ancestor
- Nonmonophyletic= subset, excludes certain descendants
- Monophyletic= all descendants
- Doesn’t reflect evolutionary relationships
Parsimony
- The fewest character transitions are best in phylogeny
- Used to determine best relationships btwn groups
Bacteria
- Most currently known prokaryotes
- Domain of life
Archaea
- Diverse group of prokaryotes
- Inhabit wide variety of environments
- Domain of life
Eukarya
- Organisms w/ true nuclei
- Domain of life that consists of kingdoms plantae, animalia, and fungi
Major challenges multicellular organisms must overcome
- Structure
- Coordination
1. Development
2. Internal Message - Reproduction
- Getting cells what they need
1. Transport
2. Gas exchange
Structure
- Not much of a problem for cell (cell wall, movement)
- Woody tissue of tree
- Human= skeleton
Coordination
- Cell- make sure cells do job, signal transduction
- Plants and animals
1. Development: tree (seedling to big plant), egg–> adult
2. Internal message: communication btwn cells
Getting cells what they need (food, water, air)
- Single cell- slurping up stuff
- Plants and animals: roots in plants, internal messaging, internal transport and gas exchange
Reproduction
- Single cell- mitosis
- Plants and animals- 1 cell to many
Why be Multicellular?
-Division of labor/ specialization
Why to NOT be multicellular
- Some cells must forgo reproduction
- Natural selection should favor those that “cheat”, reproduce anyways and do not cooperate
Cell
-The fundamental unit of life, structure, and function
Organ
-A specialized center of body function composed of several different types of tissue
Tissue
-An integrated group of cells with a common function, structure, or both
Roots system
- Consists of roots
- Absorbs minerals and water, stores carbs
Shoot system
-Consists of stems and leaves
Stems
- Plant organ bearing leaves and buds
- Function: elongate and orient the shoot to maximize photosynthesis by leaves, elevate reproductive structures, dispersal of pollen and fruit
Nodes
-Point at which leaves are attached
Internodes
-Stem segment between nodes
Apical bud
-Growing shoot tip, where growth of young root is concentrated
Axillary Bud
- Upper angle formed by each leaf and stem
- Can form branch, thorn, or flower
Leaves
- The main photosynthetic organ
- Function: gas exchange, dissipate heat, defend from herbivores and pathogens
Veins
-Vascular tissue of leaves
Xylem
-Conduct water and dissolved minerals from roots to shoots
Phloem
-Transport photosynthate to where they are needed (roots and sites of growth)
Primary Growth
- Growth in length
- Meristems: apical meristems located at root and shoot tips
Secondary Growth
- Only in woody plants
- Growth in thickness
- Meristems: Lateral meristems extending along root or shoot where primary growth has ceased
Root cap
- Protects the apical meristem as root pushes through soil
- Secretes polysaccharide slime that lubricates soil around tip of root
Zone of cell division
-Produces new root cells
Zone of elongation
- Growth occurs as root cells elongate
- pushes tip father into the soil
Zone of differentiation
-Cells differentiate/ become distinct cell types
Apical dominance
-Tendency for growth to be concentrated at tip of plant shoot bcuz apical bud partially inhibits axillary bud growth
Explain why growth rings form in tree trunks, and why the width of ring varies from year to year.
-Vascular cambium appears as a ring. As cells divide, it’s circumference increases, adding secondary xylem to inside and secondary phloem to outside. Ring size varies depending on weather that year
Ectoderm
- Embryonic tissue
- Germ layer covering the surface of the embryo
- Function: protection
- gives rise to the outer body covering of the animal and CNS
Endoderm
- Embryonic tissue
- Innermost germ layer
- Lines pouch that forms during gastrulation
- Gives rise to lining of digestive tract and lining of liver and lungs
Mesoderm
- Embryonic tissue
- Fills the space btwn ectoderm and endoderm
- Makes up muscles and organs
- Only in bilateral
Epithelial Tissue
- Function: Interface for exchange (uptake/waste)
- Polar- has attachment point and point of exposure
- Apical or basal
- Types: cuboidal, simple columnar, simple squamous, pseudostratified columnar, stratified squamous
Connective tissue
- Function: holds many tissues and organs together
- Structure: extracellular matrix
- Types: loose, fibrous, bone, blood, adipose, cartilage
Muscle tissue
- Function: movement
- Types: skeletal, smooth and cardiac (involuntary)
Nervous tissue
- Function: receipt, processing, transmission of info (sending and receiving signals)
- Structure: connections (unusually tight)
- Types: neurons and glia
Metabolic Rate
-Sum of the energy animal uses
Metabolism
- Net use of energy (input vs output)
- Bring in food, release heat and waste
- Studied through calories (food v waste), respiration, temperature change
How does the body control and coordinate itself
-Nervous system and endocrine system
Endocrine system
- Signal: hormones
- Path: bloodstream and diffusion
- Specificity: low- signal reception in target cell
- Duration: long- stays in environment depending on quantity and stability
Nervous system
- Signal: nerve impulse (electric)
- Path: Nerve cells (specific)
- Specificity; high
- Duration: short
Endotherm
- Maintain constant body temp
- Uses more energy
- Moves faster, thinks faster
- Bigger= requires more input
- Per pound, being bigger takes less energy (smaller animal= faster metabolism)
Ectotherm
-Adjust body temp to environment
Endocrine system fxn
-Coordination of body activities (digestion and metabolism)
Differences btwn metabolic rates
- How big/small an animal is
- Activity
Muscle hierarchy
-Muscle–> muscle fibers–> myofibrils–> sarcomere (end to end)–> thick (myosin) or thin (actin) filaments
How do myosin and actin overlap?
- Myosin head and ATP bind
- ATP–> ADP and p, myosin head moves back and binds to actin
- Myosin head binds with actin, releasing ADP and p, creates crossbridge
- Myosin head moves back to original spot, ready to bind again
Tropomyosin
- Blocks binding of myosin to actin when calcium is absent
- Synapse can trigger release of calcium ion channel to help muscle contract
Hydrostatic Skeleton
- Longitudinal muscles= length
- Circular muscles= width
- Peristalsis= squeezes coelem fluid for movement forward
Exoskeleton
- Doubles as armor
- Forms joints
- Articulated
- Appearance communicates behavior
- Con: Molt skeleton when too small, vulnerable btwn molts
Endoskeleton
- Never outgrown (grows with u)
- Con: need other ways of protection, communication
Water as environment for locomotion
- Gravity= less of a problem (buoyancy)
- Friction= substantial friction (thick and sticky if polar)
- Methods= undulating, paddling, squirting, creating low pressure
Land as environment for locomotion
- Gravity= big challenge
- Friction= depends on how much of body in contact w/ ground
- Methods=Walking/ running, peristalsis, slittering
Air as environment for locomotion
- Gravity= biggest challenge
- Friction= varies
- Methods= flying
Water pathway from roots
-Mycorrhizae (fugus)–> plant tissue–> epidermal cells–> apoplast and symplast
Apoplast–> casparian strip–> symplast–> root xylem
