Evolution by natural selection

1. Variation exists

2. Some of this variation is heritable

3. More offspring are produced than can survive setting up a struggle for existence

4. Individuals with favorable variations survive better, leave more offspring

5. In next generation, more individuals will possess favorable variations.

Evolution

- Species change over time

- Species are related

Speciation

The formation of new species

Allopatric Speciation

The formation of a new species as a result of an ancestral population's becoming isolated by a geographic barrier.

Sympatric Speciation

Formation of new species as a result of a genetic change that produces a reproductive barrier between the changed population(mutants) and the parent population.

- Occurs without a geographic barrier.

Photo-autotrophs

Harness light energy to drive the synthesis of organic compounds from CO2

-Energy Source: SUNLIGHT

-Carbon Source: CO2

EX: plants and algae

Chemoautotrophs

These prokaryotes extract energy from certain inorganic substances

Energy Source: Inorganic chemicals

Carbon Source: CO2

EX: species that live around hot-water vents deep in seas

Photoheterotroph

Use light to generate ATP but must obtain their carbon in organic form

Energy Source: Sunlight

CArbon Source: Organic compound

Chemoheterotrophs

These are all fungi and animals

Energy Source: Organic Compounds

CArbon Source: Organic Compounds

Protozoans

-Live primarily by ingesting food

-Thrive in all aquatic envirn

-Some live as parasites in animals

Monophyletic

Includes an ancestor and all of its descendants.

Paraphyletic

a group that excludes some of the descendants of a common ancestor

Adaptations of plants for living on land

- Cuticle

-Stomata

-Vascular tissue

- Lignin-hardened cell walls

-Gametangia

-Proteted embryos

- Differentiation of the body into a subtarranean root system and above-ground stems and leaves

Cuticle

Reduces water loss

Stomata

Allows gas exchange

Shoot

-Composed of stems, leaves, flowers, fruits, and seeds

-Supports plant and it is supported by lignin (a chemical that hardens cell walls)

Gametangia

Protective structure for gametes and has a jacket of protective cells surrounding a moist chamber, so gametes won't dehydrate.

What mode of nutrition is used by both plants and algae?

They both obtain energy via photosynthesis.

Highlights of Plant Evolution

Green Algae

->

Terrestrical adaptations (Bryophytes or Mosses)

->

Seedless Vascular tissue (Ferns)

->

Seeds (Gymnosperms)

->

Flowers (Angiosperms)

gametophyte

-Haploid (they have one set of chromosomes)

-Produce gametes (sperm and eggs) which unite to form zygotes, white develop into new sporophytes

Sporophyte

-made up of diploid cells (with two chromosome sets)

-Produce spores, which can develop into a new organism without fusing with another cell, and can with stand harsh environments

Terrestrial Adaptations of Seed Plants

(1) further reduction of the gametophyte

(2) the evolution of pollen

(3) the advent of the seed - the shift toward diploid in land plants because of mutations by the sun; also only needs one good allele to survive.

Key Stages in the Angiosperm life cycle

(1) A pollen grain lands on the sticky stigma of a carpel and extends a tube down to the ovule.

(2) Then it deposits 2 sperm nuclei within the embryo sac, and one sperm cell fertilizes an egg in the embryo sac.

(3) This makes a zygote, which develops into an embryo.

(4) Second sperm fertilizes another female gametophyte, which develops into a endosperm, which nourishes the embryo.

(5)Seed is made. The ripened ovary is the fruit.

What are common features of prokaryotic organisms (Bacteria and Archaea)?

-Genes located on a single circular chromosome and sometimes on similar plastids.

-Chromosomes not seperated into a membrane-bound nucleus.

-No membrane-bound organelles or endoplasmic reticulum

-Ribosomes embedded in the cytoplasm

-No cytoskeleton

-No mitosis, meiosis, or gametes

-Flagella, if present, are a simple protein filament that rotates at its base.

These cells reproduce by budding or binary fission (asexual)

What are characteristics of bacteria?

What is the difference between gram-positive and gram-negative bacteria?

Gram-positive bacteria have a thick wall of peptidoglycan while gram negative bacteria have a thinner wall with an additional outer phospholipid membrane.

Describe how bacteria occur as solitary cells, colonies, spores, or filaments:

Colonies occur when dividing cells remain embedded within a polysaccharide sheath. Filaments form when cells divide but remain connected together in long chains (found typically in photosynthetic cells). Bacteria may form spores under adverse conditions, spores are resting cells that typically have a hard dormant wall and ar useful for dispersal and survival.

How do prokaryotes exchange and obtain energy and raw materials?

Chemo and photo- hetero and autotrophs

What are cyanobacteria?

Photosynthestic bacteria that produce oxygen as a by product, just like higher plants. Both photosynthetic and nitrogen fixing. Main sources of N2. 30% of all photosynthesis on the planet.

two main functions of the root

absorption and anchorage

what has trachery elements (xylem or phloem?)

xylem

Lamarck

inheritance of acquired characteristic

chordate

generalized vertebrate

Divergence

The splitting of one lineage into two lineages (speciation)

Reticulation

The blending of two lineages into one lineage (hybridization/viruses)

tracheids

-type of xylem 

-thick cell walls, more important for support than conduction

-elongate, tapering cell walls

-connect to adjacent tracheids by pits

-water and solutes pass from tracheid to tracheid via pits

stamen

male reproductive organ of flower

-composed of anther (brown part) and filament (stalk)

filament

stalk of stamen

pistil

female reproductive part of a plant

-wet part on end is stigma

-stalk is style

stigma

wet part of pistil

carpel

at the bottom of the pistil, houses ovule

Animal body symmetry: None and Radial

• Sponges have none because they are sessil and porus
• Cnidarians, ctenophores have radial don't have sensory organs

Animal body symmetry: Bilateral

Most phyla, cephalization- development of head, more sensory organs enable movement, hunt for food

Effector

A structure such as a muscle cell that carries out a body response.

Homeostasis

The steady-state physiological condition of the body. Has three components: a receptor, a control center, and an effector.

Regulator

A characterization of an animal in regard to environmental variables; uses mechanisms of homeostasis to moderate internal changes in the face of external fluctuations.

Receptor

Detects a change in some variable of the animal's internal environment, such as change in body temperature.

Negative Feedback

A primary mechanisms of homeostasis, whereby a change in a physiological variable that is being monitored triggers a response that counteracts the initial fluctuation.

Positive Feedback

A physiological control mechanism in which a change in some variable triggers mechanisms that amplify the change.

Thermoregulation

The process by which animals maintain an internal temperature within a tolerable range.

Brown Fat

A tissue in some mammals, located in the neck and between the shoulders, that is specialized for rapid heat production.

Food Chain

The transfer of food energy up the trophic levels from its source in plants and other photosynthetic organisms through herbivores to carnivores and eventually to decomposers.

Dynamic Stability Hypothesis

A hypothesis that proposes that long food chains are less stable than short chain due to population fluctuations.

Tertiary Consumers

Organisms that consume secondary consumers.

Primary Producers

Autotrophs

Detritus

Nonliving organic material.

Primary Production

The amount of light energy converted to chemical energy (organical compounds) by autotrophs during a given time period in an ecosystem.

Secondary Consumers

Organisms that consume primary consumers.

Contrast Microevolution & Macroevolution

Microevolution is a change in the gene pool of a population, often associated with adaptation

Macroevolution includes major changes in the history of life, such as the origin of a new species, which is often noticeable enough to be evident in the fossil record

Advantage to living on land for plants

- On land light is more available than in water since water absorbs and reflects light.

-CO2 diffuses more readily in air than in water.

Disadvantage to living on land for plants

Better Answer: Outside of water, plants have to cope with the problem of drying out.

Another good answer: On land plants have to cope with herbivores not present in the water.

Function of Vascular Tissue

-Provide support against wind and gravity

-Conduct water

Phenotypic Plasticity

Is when an organism changes it phenotype in response to the environment.

What are mycorrhizae?

Root-fungus symbiotic associations that enhance the uptake of water and minerals by the plant and provide organic nutrients to the fungus

Gastrulation

-2nd Stage in development of an ambryo

-Establishes the three major tissue layers (Ectoderm, Mesoderm, Endoderm) and the mouth and the anus of an animal

Cleavage

-A series of rapid cell divisions that result in a multicellular ball.

-DNA replication, mitosis, and cytokinesis occur rapidly

"Great Transformation" in evolutionary history.

-The evolution of animals that could live on land.

-The evolution of bipedalism

-The evolution of whales.

What does Ca2+ do for muscle contractions and what releases it?

-Ca2+ helps to expose the binding sites on the thin filaments so that myosin heads can attach to actin, initiating filament sliding.

-The Endoplasmic Reticulum(ER) relseases Ca2+ into the cytoplasm and pumps it out when the action is done

What is necessary for the generation of an action potential?

-    K+ voltage-gated channels

-  Na+ voltage-gated channels

What allows an action potential to propagate along an axon?

-The refractory period of voltage-gated Na+ and K+ channels

-The flow of positive charge away from the initial influx of positive charge

Resting Potential

- The resting potential voltage is -60mV.

- Potassium is higher on the inside than the outside, and sodium is higher on the outside than on the inside.

What do Sensory Receptors do?

- They are tuned to the condidtion of the external world and the internal organs.

-Detect stimuli such as chemicals, light, tension in a muscle, sounds, electricity, cold, heat, and touch.

- It's job is completed when it sends info to the CNS by triggering action potentials.

Mechano-receptors

- Sensory Receptor Cell

- Senses for touch, pressure, motion, and sound.

Chemo-receptors

-Sensory Receptor Cell

- Sensors for chemicals in nose and taste buds.

Electromagnetic Receptors

-Sensory Receptor Cell

-Sensors for energy such as light and electricity.

How a Muscle contracts.

- ATP binds to a myosin head, which is released from an actin filament.

- The breakdown of ATP cocks the myosin head. (High-energy position)

-The myosin head attaches to an actin binding site.

- Power stroke slides the actin (thin) filament toward the center of the sarcomere.

Physiological Role of Hormones

- To coordinate the response of an organism to a particular situation.

Open Circulatory System

- The tubular heart pumps the circulatory fluid inot the body tissues

- Nutrients then diffuse from the fluid directly into the body cells.

- At same times, contractions of body muscles move the fluid toward the tail.

-When the heart relaxes, the fluid returns to it through several pores.

EX: INSECTS

Closed Circulatory System

- Blood is always contained within vessels, separate from the interstitial fliud bathing the cells.

- The blood is pumped from the heart to the gills, to capillary beds in body tissues, and back to the heart.

EX: FISH

Function of Red Blood Cells

(Erythrocytes)

- Contains hemoglobin.

- Transports (carry and deliver) oxygen to parts of the body.

Function of White Blood Cells

(leukocytes)

- Fight infections and cancer.

-Larger than red blood cells.

- Contain nuclei an da full complement of other organelles.

Blood Clotting

- After Epithelium lining a blood vessel is damaged, platelets go to the damaged tissue to form a sticky cluster that seals minor breaks

-Platelets also release clotting factors that convert fibrinogen(protein found in plasma) into a threadlike protein called fibrin.

-Molecules of fibrin form a dense network to create a patch (scab)

Chemotaxis

Process by which a cell senses a chemical and responds by moving along that chemical gradient from low concentration to high concentration.

Diapedesis

The movement of white blood cells (leukocytes) from the blood across blood vessel walls and into tissues.

A Prokaryotic Cell would be under what domain?

(Archaea, Eukarya, or Bacteria)

Archaea & Bacteria

Characteristics of a Prokaryotic Cell

- Cell Wall

- Plasma Membrane

- Single Circular Chromosome

- Ribosomes

Characteristics of a Eukaryotic Cell

(Protist)

- Cell Wall

- Nucleus

- ER

- Golgi

-Mitochondria

Biological Species Concept

Can interbreed to produce fertile offspring.

Ecosystem

The organisms living in an area and the physical environment that surrounds them

Gross primary productivity

The total amount of energy captured by the photosynthetic organisms

**Remember: while these organisms supply all the energy to the ecosystem, they don't supply all the energy they capture because they have to survive too!

Net Primary Productivity

The portion of energy available to the rest of the ecosystem

How much energy is captured by primary consumers (gross productivity) and how much is passed on (net primary productivity)???

- .8% captured by photsynthesis (Gross Production)

- 55% of this lost to respiration

- 45% supports growth (Net Production)

~ 11% of Netenters grazing food web

~ 34% of Net enters decomposer food web

On Average how much energy is passed on to next trophic level?

~10 %

How does energy and the biomass trail relate to one another? (energy pyramid)

As you go up in each trophic level the less energy.

The size of each "block" is proportional to the biomass.

IN OTHER WORDS:

*As trophic level inrcease*

*Energy decrease*

How do nutrients flow through ecosystems?

Are they lost?

Locally and Global

- No they are recycled = biogeochemical cycles

Biomes

Major types of ecosystems that cover large geographic regions.

Factors that control nutrient cycling.

1. Rate of Decomposition of detritus.

2. The Rate of export of nutrients from the ecosystem.

What determines the rate of decomposition of detritus?

1. Environmental Conditions

- Moisture & temperature are issues

-In a cold environment things decompose slower

-Nutrient cycles will vary, so you need to understand the physical conditions of the ecosystem in order to understand the rate of decomposition

2. Quality of the detritus.

Rate of export of nutrients from the ecosystem

Causes:

-type of vegetation

Population Growth

Population Size times (births-deaths)

N*(b-d)

The Exponential Growth Model

1. The rate of expansion of a population under ideal, unregulated conditions.

2. The rate at which population grows depends on the number of individuals already in the population

***Bigger the population, the faster the population increases.

(change in population size/change in time)

OR

Rmax*N

Logistic Growth Model

-A description of idealized population that is slowed by limiting factors.

-Predicts that a population's growth rate will be low when the population size is either small or large, and highest when the pop. at an intermediate level relative to the carrying capacity.

(Change in Population size/ Change in Time)=Rmax*N*(K-N/K)

-close carrying capacity K approached 0

-away from carrying capacity K approaches 1

Density-Dependent Factor

-A population-limiting facotr whose effects intensify as the population increases in density

EX: As population size increases, competition becomes more intence, and the growth rate declines in proportion to the intensity of competition.

Density-Independent Factor

-Population-limiting factor whose intensity is unrelated to population density.

-Abiotic factors and unfavorable changes in weather.

EX: Abrupt weather changes, fire, flood, human activity.