Cause & Mechanisms for Evolution, The Scientific Method, Chapter 3.3, Chapter 3.2 Flashcards, Chapter 3.1 Flashcards, 5.1 Flashcards, Chapter 5.3: Human Nervous System, Chapter 5.4, Chapter 4: Evolution, Evidence for Evolution

Selective Pressures

environmental factors that influence the survival and reproductive success of individuals (can be biotic or abiotic)

Traits

characters/adaptations inherited from parents

Adaptations

traits that have evolved overtime through evolution to improve an individual's fitness

Inheritance

transmission of DNA to offspring

genes

segments of DNA carrying info for development of specific traits

Alleles

different versions of a gene

Allele frequency

the relative frequency of a specific allele in a population relative to total number of alleles

Natural Selection

individuals with favorable traits are more likely to survive and reproduce passing the traits on

types of natural selection

directional, stabilizing, disruptive

Directional

selection of one extreme trait

stabilizing

selection of average/intermediate trait

Disruptive

selection of both extremes

Genetic drift

random changes in allele frequency especially in smaller populations because each individual holds more weight

Bottleneck effect

original population in cup and more diverse, but an event (the bottleneck) favors only one trait and whittles down the diverse gene pool

Founder effect

genetic drift that occurs after a small number of individuals colonize a new area and gene pool there is limited to only small group

Mutations

random changes in DNA that create new alleles and introduce them to population

artificial selection

humans favor a specific trait and select only animals with that to breed

sexual selection

certain traits allow an individual to reproduce more

Gene flow (migration)

movement of alleles from one population to another through migration

What 5 circumstances must be met for a population to be in Hardy-Weinberg Equilibrium

1. No mutations occur

2. No gene flow

3. Random Mating

4. Large Population so no Genetic Drift

5. No selection

Step one

observation

step two

question

step three

background knowledge

step four scientific method

create the hypothesis

step five of the scientific method

experiment

step six scientific method

analyze results

step seven

conclusion

Cell Membrane (Plasma Membrane)

A semipermeable boundary that surrounds the cell and controls what enters or exits.

Homeostasis

Maintaining a stable internal environment despite changes outside.

Phospholipid

A molecule with a water-attracting (polar) head and water-repelling (nonpolar) tails that makes up the membrane.

Lipid Bilayer

Two layers of phospholipids that form the basic structure of the cell membrane.

Selective Permeability

The ability of the cell membrane to control which substances can pass through.

Concentration Gradient

A difference in the concentration of a substance across a space.

Water Potential

the physical property that predicts the direction in which water will flow (from high h2o pot. to low h2o pot.)

Diffusion

The movement of molecules from high to low concentration—no energy required.

Osmosis

The diffusion of water across a membrane.

Passive Transport

Movement of substances across the membrane without energy

Active Transport

Movement of substances across the membrane using energy (from low to high concentration).

Simple Diffusion

Substances move directly through the membrane.

Aquaporins

Channel proteins for water that facilitate its movement across the membrane.

Hypotonic Solution

Less dissolved stuff outside, causing the cell to swell as water moves into the cell.

Hypertonic Solution

More dissolved stuff outside, causing the cell to shrink as water moves out of the cell.

Isotonic Solution

Equal concentration inside and out, causing the cell to stay the same as water moves in and out equally.

Facilitated Diffusion

Substances move from high to low concentration using proteins.

Channel Proteins

Proteins that are always open, providing a fast pathway for substances.

Gated Channel Proteins

Proteins that open or close in response to signals.

Carrier Proteins

Proteins that change shape to carry molecules across the membrane.

Amphipathic Proteins

Proteins with both hydrophilic/polar and hydrophobic/nonpolar regions.

Endocytosis

Membrane folds inward to bring substances into the cell in vesicles.

Exocytosis

Vesicle fuses with membrane to send substances out of the cell.

Barrier Function

Keeps the inside of the cell separate from the outside.

Transport Function

Controls what enters and exits (via diffusion, transport proteins, etc.).

Communication Function

Proteins can send and receive signals.

Structure Function

Provides shape and allows interaction with the environment.

9 of Life Characteristics

HOME HERD; homeostasis, organization (cell theory), metabolism, (response to) environment, heredity, evolution, reproduction, development

Characteristic Sub-Cellular Units

Not alive on their own.

Atom

Basic unit of matter (e.g., carbon, oxygen).

Ion

Atom with unequal protons and electrons.

Cation

type of ion with + charge (more protons).

Anion

type of ion with − charge (more electrons).

Molecule

Two or more atoms joined together.

Nonpolar

describes a molecule with no charge; avoids polar/charged molecules and clusters together; only types of

Polar

Slight + and − areas; attract opposite charges.

Charged

Full + or − charge.

How can molecules diffuse through the membrane

Small nonpolar molecules diffuse freely through the cell membrane; small uncharged polar molecules can cross slowly; large polar molecules and ions require transport proteins.

Biomolecules

Large molecules made of many atoms.

Lipids

Biomolecule that stores energy, make up cell membranes (most are non-polar)

Nucleic Acids

Biomolecule that Stores genetic info (DNA, RNA).

Proteins

Biomolecule that helps with digestion, metabolism, and DNA replication (enzymatic activity), transportation through cell membrane, and communication with other cells

What is an enzyme

type of protein that helps chemical reactions take place under milder conditions (the artificial way of speeding up chemical reactions)

Carbohydrates

Biomolecule that Stores energy, help in cell communication by attaching to proteins on cell membrane

Nucleus

Organelle that Stores DNA; controls cell.

Mitochondria

Organelle that Makes energy (ATP) from chemical reactions (has TONS of enzymes)

Ribosomes

Organelle that Makes proteins with amino acids from info from RNA

Vesicles

Organelle that Transports materials in cell. Jobs: transporting, secreting (get rid of junk), lysosomes (break down waste)

Vacuole

Organelle that Stores water and nutrients (large in plants).

Lysosomes

Organelle that is a type of vesicle and breaks down waste.

Endoplasmic Reticulum (RER & SER)

Rough: makes and processes proteins with ribosomes Smooth: makes lipids and detoxes substances

Rough ER

Organelle that Makes proteins (has ribosomes).

Smooth ER

Organelle that makes and stores lipids

Golgi Apparatus

Gets lipids and proteins from ER, sorts and modifies them, sends them off in vesicles.

Chloroplast

(Organelle in plants only) Converts sunlight into energy (photosynthesis).

Prokaryotic cells

No nucleus or membrane-bound organelles, but do have ribosomes. includes bacteria and archaea

Eukaryotic cells

Larger, complex, with nucleus, membrane bound organelles, DNA tightly wrapped around histone proteins in chromosomes, cellulose in plant cell walls. Includes Protists, plants, fungi, and animals

Tissue

Group of similar cells doing a specific function.

Organ

Group of tissues working together.

Organ System

Group of organs doing a larger job.

Organism

Comprised of multiple organ systems; an individual living being that shows all characteristics of life and can reproduce to create a new organism.

Population

A group of the same species living in one area.

Community

All the different species in one area.

Ecosystem

All biotic communities + abiotic parts of an area.

Biome

A large region with a specific climate and ecosystems.

Biosphere

Everywhere life exists on Earth. Includes: air, water, land

Cell

The basic structural and functional unit of all living things.

Unicellular organisms

Organisms made of one cell, such as bacteria.

Multicellular organisms

Organisms made of trillions of cells, such as humans.

Cell theory

The principle that all living things are made of cells, and all cells come from earlier cells.

Unity and Diversity of Cells

All cells share a common ancestry and core structures but can look and act differently based on their function.

Core Structures Found in ALL Cells

Cell membrane, cytoplasm, DNA, and ribosomes.

Cell membrane

Controls what enters and exits the cell; acts as a protective boundary.