Concepts of Biology Exam #2

Speciation

The evolution of a new species, occurs when a population becomes reproductively isolated from other members of the species

Speciation requires what 2 things

1. Populations must separate from each other physically 2. Then populations become reproductively isolated

Allopatric speciation

occurs due to geographic/physical isolation

Sympatric speciation

occurs within the same geographic region

RIM

Prevent the flow of genetic material among populations, and preserve the genetic integrity of each species by preventing reproduction

Species

Group of organisms that can successfully interbreed and produce fertile offspring

Pre/Post Zygote

Pre: reduce the chance of zygote formation

Post: reduce the survival and reproduction of hybrid offspring

Forms of Isolation

Ecological Isolation, Behavioral Isolation, Temporal Isolation, Mechanical Isolation

Basic Structure of a Cell

Cell membrane, Cytoplasm, nucleus

Major cell components

Cell/Plasma membrane, nucleus, ribosomes, endoplasmic reticulum (smooth and rough), Golgi body, vesicles, mitochondria, chloroplasts (plants)

Extinction

The end of a lineage

Unicellular, multicellular, and colonial

Uni - single-cell organism, colonial - multiple cells working together doing the same thing, multi - multiple cells doing different functions

Organelles

Specialized structures with particular functions

What are cells?

The smallest unit at which all life processes can occur

Nucleus

The control center, most prominent organelle, contains DNA, has phospholipid bilayer

Cell Membrane

Provides structure, is the boundary between cell and external environment, and regulates what goes in and out of the cell

Phospholipids

An important component of cell membranes, amphipathic, forms a natural bilayer

Fluid Mosaic Model

Membranes are made of a variety of different molecules that can move around the membrane

Traits

Characteristics that are inherited

Membrane Functions

Diffusion, passive transport, active transport

Ribosomes

The little spots, help build proteins, lots of them

Diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration.

Osmosis

The diffusion of water through a cell membrane

Passive/Active transport

Passive: High to low (no energy needed)

Active: Low to high (requires energy)

Vesicle mediated transport

Two forms that carry stuff in and out of the cell

Golgi Apparatus

Receives, processes, packages, and ships proteins and lipids, makes vesicles

E.R

Huge folded membranes, type determines presence or absence of ribosomes, has smooth or rough

Rough/Smooth ER

Rough: has ribosomes, helps process proteins

Smooth: does not have ribosomes, helps process lipids

Mitochondria

Powerhouse of the cell, converts molecules into ATP, double-membrane system, and has their own DNA

ATP

A special form of energy, essential for life

Chloroplasts

Site of photosynthesis, converts light energy to chemical energy

Energy

The capacity to do work (chemical, heat, radiant, electrical)

Vacuoles

Intracellular sacs, some are storage, some pump water out of a cell, many plant cells have a very large central vacuole

Pro vs. Eukaryotes

Pro: simple, no nucleus or organelles, small, bacteria

Eu: complex, nucleus and organelles, large

Laws of Thermodynamics

1. Energy cannot be created or destroyed

2. Entropy tends to increase

Entropy

The state of disorder

Work

Any change in the state or motion of matter, most important work: survival and reproduction

Homeostasis

maintenance of a relatively constant internal environment despite the external environment

Fitness

The ability to survive and reproduce

Natural Selection

Organisms with certain traits are more likely to survive and reproduce than other organisms

Metabolism

The sum of all chemical activities within the individual

Metabolism = Catabolism + Anabolism

Anabolism

Processes that makes complex molecules from simple ones, amino acids into proteins

Catabolism

Processes that break down complex molecules into simple ones, release of energy

Endocytosis

moves stuff to the inside of the cell (encased in phospholipids)

Exocytosis

moves stuff outside of the cell (encased in phospholipids)

Photosynthesis

conversion of light energy into stored chemical energy of organic molecules

Respiration

conversion of energy from chemical bonds in nutrients to ATP energy

Respiration Equation

Glucose + Oxygen --> Carbon dioxide + water + ATP

Pigments

light absorbing molecules

Light Reactions

light excites electrons which are used to make ATP, oxygen is a waste product here,

Dark Reactions

Takes energy from ATP and stores it in a more stable sugar molecule

Glucose

A sugar

Anaerobic

Less efficient (only gives 2 ATP), produces a toxin

Aerobic

1. Glycolysis 2. The Citric Acid Cycle (Kerbs) 3. Electron Transport of Chemiosmosis

Glycolysis

Splits glucose, in process of generating a net ATP (lose 2, gain 4), happens outside the mitochondria

Citric Acid Cycle

Completes the breakdown of carbon molecules into CO2, makes some ATP, generates NADH, recycles used materials

Electron Transport Chain

Most important step, generates ATP from NADH, huge return of ATP (32 ATP per molecule), Oxygen removes waste to maintain diffusion

Matter

Anything with mass; takes up space

Gradualism

Slow changes

Punctuated Equilibrium

Change happens in quick spurts

Fluorescence

An electron emits a low-energy light wave and goes back to normal

Equation for Photosynthesis

Carbon Dioxide + Water → Glucose + Oxygen

Phagocytosis

using endocytosis to eat food particles