BISC 208 Final Exam; UDel (Mahaffy)

Evolution

change in allele frequency

Evolutionary Principles (3)

1) competition occurs when there are more individuals than can survive

2)when there is variation, the adaptive traits are passed on and increase in frequency in the population

3) Evolution is derived from natural and sexual selection

Microevolution

Small changes in allele frequency

Macroevolution

Creation of new species

Natural Selection Patterns (3)

1) Stabilizing

2) Disruptive

3) Directional

Stabilizing Selection

NS against the extremes

Disruptive Selection

NS against the average

Directional Selection

NS against one extreme

Hadry-Weinberg Equilibrium

When conditions are met, allele freq. will not change

Hardy-Weinberg Principles (5)

1) No migration

2) Large population

3) Random mating

4) No mutation

5) No selection

Selection

The process by which certain traits or characteristics become more or less common in a population over time.

Selection Types (4)

1) Natural

2) Sexual

3) Artificial

4) Ecological

Genetic Drift

Random changes in the frequency of alleles--changes that occur w/o selection

Main Mechanisms of Genetic Drift (2)

1) Bottleneck

2) Founder Effect

Bottleneck Effect

population is suddenly reduced to a very small size because of events like natural disasters, disease, or hunting

Founder Effect

small group of individuals breaks away from a larger population and starts a new population

Genetic drift leads to (2)

1) loss of genetic variation

2) Inbreeding

Inbreeding leads to

An increase in the frequency of homozygotes in the population

Species

Has multiple definitions that depend on appearance, location, niche, and reproduction

Speciation

The formation of new and distinct species.

What leads to speciation

Reproductive Isolation

Allopatric Speciation

A type of speciation that occurs when populations of a species become geographically isolated from each other.

Sympatric Speciation

A type of speciation that occurs when two species reproduce but the populations fill different niches. Eventually the become so different they cant reproduce.

Polyploidy

Polyploidy is a condition in which an organism has more than two complete sets of chromosomes.

Normally, organisms are diploid (2 sets of chromosomes), but polyploid organisms may have:

• 3 sets (triploid = 3n)

• 4 sets (tetraploid = 4n)

• or more.

Autopolyploidy

Autopolyploidy is a condition in which an organism has extra sets of chromosomes that all come from the same species.

Allopolyploidy

Allopolyploidy is a condition in which an organism has extra sets of chromosomes from two different species.

Prezygotic Speciation (6)

1) Geographic: separated by physical barriers

2) Ecological: two species live in same general area, but occupy different habitats or niches so they dont encounter each other

3) Behavioral: different species have different mating behaviors

4) Temporal: species reproduce at different species

5) Mechanical: physical differences

6) gametic: sperm and egg are incompatible

Postzygotic Speciation (3)

1) Hybrid Inviability: embryo may be weak, unable to survive

2) Hybrid Sterility: reproductive system does not work properly

3) Hybrid Breakdown: first generation of hybrids are healthy and fertile, future generations are weaker

Resource Partitioning

Over time, species may evolve specialized traits or behaviors that allow them to exploit specific resources, contributing to speciation

Hybrids

When two species mate and the offspring has no reproductive issues

Evolutionary Radiation

One ancestral species rapidly evolves into many different species

Anogenesis

Single species evolves into a single different species

Cladogenesis

Single species evolves into multiple new species

Nontracheophytes (3)

1) Mosses

2) Liverworts

3) Hornworts

Seedless Plants (4)

1) Whisk Fern

2) Club Mosses

3) Horsetails

4) Fern

Gymnosperms; Naked Seeds (4)

1) Ginkgos

2) Cycade

3) Gnetophytes

4) Conifers

Angiosperms; Fruiting Flowers (2)

1) Monocots

2) Eudicots

Monocots Traits (6)

1) Single cotyledon (embryonic leaf) seed structure

2) Parallel leaf venation

3) Floral parts in multiples of three

4) Fibrous root system (thin and branch out)

5) Scattered vascular bundles

6) Primary growth (upward)

Eudicot Traits (6)

1) Double cotyledon seed structure

2) Net-like leaf venation

3) Floral parts in multiples of four or five

4) Taproot system (central main root)

5) Ring-like vascular bundles (xylem and phloem are in neat circle or ring)

6) Secondary growth (thickness)

Secondary Metabolites

Organic compounds that are not directly involved in the normal growth, development, or reproduction of an organism. (Caffeine, Capsaicin, Etc)

What grown first in a seed

Root

Plant Organs (3)

1) Roots

2) Stem

3) Leaves

Roots Function

Absorb nutrients in soil, anchor plant, and store food

Root Meristem

A cluster of active, dividing embryonic cells at the tips of roots that generates new tissue and increases root length

Root Cap

A structure that covers the tip of a root, protecting the root from injury

Root Hairs

Tiny hair-like extensions that increase the surface area of the root allowing it to absorbs more water and nutrients

Vascular Cylinder Parts

1) Epidermis

2) Cortex

3) Endodermis

4) Pericycle

5) Phloem

6) Xylem

Stem Function

Support, transport, storage

Node

A region on a stem where a leaf, branch, or flower is or was attached

Internode

Segment of the stem between two adjacent nodes

Apical Bud

located near the shoot tip and causes elongation (primary growth) of a young shoot

Lateral Bud

Buds along the sides of a stem that give rise to new branches (secondary growth).

Leaves Function

Photosynthesis and gas exchange. Can be specialized for reproduction, etc.

Blade

Thin, flattened section of a plant leaf that collects sunlight

Petiole

The stalk of a leaf, which joins the leaf to a node of the stem.

Stomata

Small openings on the underside of a leaf through which oxygen and carbon dioxide can move

Guard Cells

Control the opening and closing of stomata

Stamen

The male reproductive organs of a flower

Anther

Produces Pollen

Filament

Supports the anther

Pistil

The female reproductive organs of a flower

Stigma

Receives pollen

Style

Connects stigma to ovary

Ovary

The swollen base of the pistil that contains one or more ovules. After fertilization, it develops into the fruit.

Plant Tissue Types (3)

1) Dermal

2) Vascular

3) Ground

Dermal Tissue

the protective outer covering of a plant

Trichomes

Tiny, spikelike projections on some leaves for protection

Cuticle

A waxy covering on the surface of stems and leaves that acts as an adaptation to prevent desiccation in terrestrial plants.

Vascular Tissue

Transports water and nutrients

Xylem

Carries water upward from the roots

Tracheids

Tube-shaped cells that carry water and minerals up from the roots

Vessel Elements

Structures that, along with tracheids, make up xylem

Phloem

Carries organic material downward

Sieve Tube Members

Cells in the phloem tissue that lack a nucleus, but are long and cylindrical for conducting carbohydrates

Companion Cells

The active cells found next to sieve tube elements that supply the phloem vessels with all of their metabolic needs

Casparian Strip

waterproof strip that surrounds plant endodermis cells

Ground Tissue

Tissue between the dermal tissue and vascular tissue of a non-woody plant that functions in photosynthesis, storage, and support

Pith

Interior to vascular

Cortex

Exterior to vascular

Plant Transport Routes (3)

1) Symplastic

2) Appoplastic

3) Cohesion-Tension

Symplastic Route

Water travels through cytoplasm and doesn't use casparian strip

Appoplastic Route

Water travels between cells & the casparian strip filters

Cohesion-Tension Theory

Water moves into the plant and continuously flows up the

xylem because of cohesion from water above it evaporating through the leaves pulling it up.

Animal Characteristics (5)

1) Monophyletic

2) Multicellualr Eukaryotes

3) Aerobic

4) Heterotrophic

5) 3 Embryonic layers

Animal Embryonic Layers (3)

1) Ectoderm

2) Mesoderm

3) Endoderm

Ectoderm

Outermost germ layer; Forms integumentary, nervous, and sensory system

Mesoderms

Middle germ layer; Forms internal structures (muscles, most organs, bones)

Endoderm

Innermost germ layer; Forms digestive tract, and respiratory system

Monophyletic

ALL descendants came from one common ancestor

Aerobic

Requires oxygen

Heterotrophic

Organisms that obtain their nutrients or food from consuming other organisms.

Hydrostatic

Hydrostatic refers to the pressure or support created by a fluid, usually water, in a confined space. Example: earthworms

Features For Grouping (5)

1) Symmetry

2) Cephalization

3) Gut type

4) Coelom type

5) Segmentation

Protostomes Characteristics (4)

1) Mouth => Anus

2) Spiral Cleavage

3) Coelom forms by splitting

4) Mosaic Embryo (no cell arrest)

Proifera

-Sponges, Corals

-Asymetrical

-No cephalization

-No gut type (Filter Feed)

-Acolemate

-No Segmentation

Cnidaria

-Jellyfish

-Radial Symmetry

-Limited cephalization (nerve net)

-sac gut

-acoelomate

-no segmentation

Platyhelminthes

-flatworms

-bilateral symmmetry

-cephalization

-sac gut

-acoelomate

-no segmentation

Rotifera

-microscopic organisms

-bilateral

-cephalization

-tube gut

-pseudocoelomate

-no segmentation

Nematoda

-roundworms

-bilateral

-cephalization

-tube gut

-pseudocoelomate

-no segmentation

Mollusca

-clams

-bilateral

-cepalization

-tube gut

-coelomate

-no segmentation