Bio 1033 - Exam 1

Chapter 1-5

Evolution

is the process of change over time that has resulted in the array of organisms found on Earth.

The result of evolution is

An organism's adaptations to its environment (described by Charles Darwin)

T/F An organism cannot evolve; the process requires multiple generations.

True

Biology is about

Asking questions about the living world and seeking answers through scientific inquiry are the central activities of biology.

10 Levels of Biological Organizations

Biosphere, Ecosystems, Communities, Populations, Organisms, Organs, Tissues, Cells, Organelles, Molecules

Biological organizations Levels - Smallest to Largest

• atom

• molecule

• organelle

• cell

• tissue

• organ

• organ system

• organism

• population

• community

• ecosystem

• biosphere

Chemical elements in an ecosystem

Recycle within the ecosystems, and are being constantly reused

Both Prokaryotic cells and Eukaryotic Cells

Use the external membrane to regulate the passage of materials from and to surroundings

*a membrane boundary separates the interior and exterior of every cell

Eukaryotic cells

• All other forms of life are composed of this type of cell (plants and animals)

• Contains membrane enclosed organelles

• Chloroplast is an organelle found only in this cell to carry out photosynthesis

• This cell is usually bigger than prokaryotic cells

• DNA (throughout the nucleus)

• Nucleus (membrane-enclosed)

• Uni-cellular or Multi-cellular organisms

Prokaryotic Cells

• Lacks a nucleus or other membrane-enclosed organelles

• Found in two groups of single-celled microorganisms, bacteria and archaea (prokaryotes)

• Uni-cellular organisms

• Generally smaller than Eukaryotic cells

DNA encodes information by

using the sequence of nucleotides (A, T, C, and G) to encode the information in genes

Nucleotides are

the basic building blocks of nucleic acids like DNA and RNA

RNA

• single stranded

• Uses A, C, G, U - (replaces T that is in DNA)

Interaction: Tree and its physical environment

they alter each other

The universal genetic language of DNA is common to virtually all organisms on Earth, however diverse, why is this?

All living things share a common genetic language of DNA because they share common ancestry

Natural Selection

• requires genetic variation

• requires selective pressure from the environment

• involves differential reproduction success

Natural Selection Example

After several unusually cold winters, squirrels with an extra layer of fat have more offspring

Natural Selection has 2 requirements, what are they?

• genetic diversity in a population

• selective pressure for heritable traits affecting fitness

Evolution through natural selection will occur most rapidly for populations of plants that

reproduce sexually and live in an unstable environment

Taxonomy is

the branch of science that classifies, identifies, names organisms

8 categories used to classify all life (most inclusive to least inclusive)

• Domain

• Kingdom

• Phylum

• Class

• Order

• Family

• Genus

• Species

*Dear King Philip Came Over For Great Soup

3 Domains of Life

• Bacteria

• Achaea

• Eukarya

Bacteria and Archaea are

the common ancestor of all life

Archaea and Eukarya are

the last common ancestor of Archaea and Eukarya

4 Kingdoms of the Eukarya Domain

• Kingdom Animalia - multicellular

• Kingdom Plantae - multicellular

• Kingdom Fungi - multicellular

• Protisia - Unicellular or multicellular

3 classes of how they acquire their energy

• producers - make their own food (autotrophs)

• consumers - eat other living organisms (heterotrophs)

• decomposers - waste and dead organisms

Where is most energy utilized by life

The sun

(with every transfer of energy, energy is lost as heat

Scientific method is

a procedure used to answer questions, test ideas, and gain scientific knowledge

What does the scientific method start with

observation and a question

Parts of the scientific method

Prediction - expected outcome, can be correct or incorrect

Hypothesis - proposed and testable explanation for an observation (what and why) assumption made before research is done

• observation → question → hypothesis

Theory - testable and broad hypothesis of many observations, supported by evidence, set of ideas explaining a phenomenon in nature

Steps of scientific method

• Observation → Hypothesis → Experiment → Data Analysis → Conclusion → Peer Review & Publish.

3 basic theories of biology

1. Cell - all organisms are made of cells, all cells come from preexisting cells- form the structure of tissues and organs

2. Homeostasis - all organisms maintain a relatively consistent interval environment

3. Evolution - all organisms evolved from a single common ancestor

deductive reasoning

• often if/then

• general statement to specific statement

biological sciences have a set of methodologies which are based on

experimental inquiry

Why is the theory of evolution not classified as a hypothesis?

because it is supported by a variety of substantial and well-supported data

T/F Theory is an educated guess

False

The process of scientific inquiry

• it is possible to test hypotheses, such as those involving historical events, without conducting experiments

Protists

includes organisms with unicellular, colonial, and multicellular organization

System: biology

is the study of interactions within a biological system to understand its behavior

What kind of characteristics is present in both viruses and other living entities

Reproduction

The Role of Hydrogen bonding in the properties of water is

to contribute to water’s high specific heat and surface tension

What combination of cells illustrates the complexity and diversity in human multicellular organisms?

Neurons, blood cells, and epithelial cells

Vertical scale

hierarchy of life

Horizontal scale

diversity of life

Erwin Chargarr found that in DNA, the ratios of (A, T, G, and C) are equal, this is the study at what level in life’s hierarchy

molecular

Community

groups of different species residing in a given area

Bond that is formed between the hydrogen and oxygen atoms in a water molecule

covalent bond

When a cell is exhibiting high levels of ATP production and protein modification, what two organelles are most likely responsible for these activities?

Mitochondria and Golgi apparatus

• *Mitochondria - produces ATP through cellular respiration, which proves the cell with energy

• *Golgi apparatus - modifies, sorts, and packages proteins for use within the celI

In an desert ecosystem, what is considered abiotic factors?

sand and temperature

• *Abiotic factors are the non-living physical and chemical components of an ecosystem, such as sunlight, temperature, water, and soil

Biosphere is

the region of Earth where life exists, encompassing all ecosystems

Example of an emergent property in a biological system

A flock of birds exhibiting coordinated flight patterns

• *emergent property: when individual components interact to produce new characteristics not present in the parts alone

Level of life's organizational hierarchy directly precedes tissues

Cells

Chemical bonding involves

the combination of atoms to form a molecule

When a cell is unable to synthesize lipids and proteins efficiently, which organelle is likely malfunctioning?

Endoplasmic reticulum

• they are responsible for the synthesis of most lipids (smooth ER) and proteins (rough ER)

Tissues

groups of similar cells that perform a specific function

Organelles

structures inside cells that carry out distinct tasks necessary for cell survival

• ex: nucleus, mitochondria, and ribosomes

Molecules

Combinations of atoms bonded together, forming the basic chemical units of a substance, essential in both living and nonliving matter

Example of an organism responding to an environmental stimulus

A plant growing roots downward due to gravity

Examples of homeostasis in humans

sweating to cool down when body temperature rises

Regulating blood sugar levels through insulin.

• *homeostasis refers to body's ability to maintain a stable internal environment despite external changes

Meiosis involves

the role of DNA in heredity

• Is the process that directly involves the role of DNA in heredity because it is the type of cell division that produces gametes (sperm and egg cells) with half the usual number of chromosomes

T/F Asexual reproduction results in offspring that are genetically identical to the parent

True

What elements are changeable in an experiment?

Independent variable and dependent variable

A research team is planning to test a certain drug's effectiveness in treating diabetes in humans. Which of the following will be the control group?

Diabetic patients who will not receive the drug

T/F independent variables can be manipulated by the researcher and are thought to directly affect the dependent variable

True

How many hydrogen bonds does each water molecule form in the crystalline lattice of ice?

Four!

Example of the property of cohesion

Capillary action in plants

• *cohesion - is a property that refers to the attraction between molecules of the same kind

Low pH is equivalent to a _____ concentration of protons and high pH means  _____ concentration of protons.

high; low

Organic molecule

molecules that contain hydrogen and carbon atoms which are covalently bonded to other molecules

• protein

• carbohydrates

• lipids

• nucleic Acids

How many glucose molecules are present in a polymer of glucose with molecular formula C₁₂H₂₂O₁₁:

02 (two)

• Single Glucose Molecule: C₆H₁₂O₆

• Multi: C₆H₁₀O₅ = H_{12 -}H₁₀ =2

Unsaturated fatty acids have single carbon-carbon bonds in their hydrocarbon backbones, whereas

saturated fatty acids have double carbon-carbon bonds

How does the sulfhydryl group contribute to the tertiary structure of proteins?

By forming disulfide bonds that stabilize the protein's overall structure.

Monosaccharides pair with

Carbohydrates

Sterols pair with

Lipids *not Protein

DNA pairs with

Nucleic Acid

Triglycerides pair with

Lipids

What is found in plant cells but not animals cells?

chloroplast

How do symporters differ from uniporters in their function?

Symporters transport multiple molecules in the same direction simultaneously.

Proton

• symbol p

• positive + 1 charge

• mass of ~ 1 amu (atomic mass unit) like neutrons

Neutron

• symbol n

• 0 /no charge

• mass of ~ 1 amu (atomic mass unit) like protons

Electron

• symbol e

• negative - 1 charge

• mass of ~1/2000 amu (atomic mass unit)

When sunlight hits an electron, what happens?

• it can move out to a higher electron shell

• it can stay in its original shell

When an electron absorbs the required amount of light energy, it moves from a ___ electron shell to a ___ electron shell, which is ____ from the nucleus.

Lower, Higher, Farther From

When an electron loses a discrete amount of energy, it moves from a ___ electron shell to a ___ electron shell, which is ____ to the nucleus.

Higher, Lower, Closer to

What is the atomic number of an atom that has 6 protons, 6 neutrons, and 6 electrons?

6

• This is an atom of carbon, an element with 6 protons. Atomic number is the number of protons in an atom.

How would properties of the water molecule be affected if O and H had the same electronegativity?

The covalent bonds of water molecules would not be polar (would be nonpolar), so no regions of the molecule would carry partial charges and water molecules would not form hydrogen bonds with each other. Water would therefore not have the unusual properties described in this chapter, such as cohesion, surface tension, high specific heat, high heat of vaporization, and versatility as a solvent.

Electron microscope

• (EM)

• focuses a beam of electrons through the specimen or onto its surface

• resolution is inversely related to the wavelength of the light or electrons

• can view proteins to lipids most plant and animals cells

Light Microscope

• (LM)

• visible light is passed through the specimen and then through glass lenses

• methods for enhancing contrast includes staining or labeling cell components to stand out visually

• can view ribosomes (super resolution microscopy) to frog eggs

Endosymbiosis theory

• theory that mitochondria and chloroplasts were once independently living bacteria

• 1.5 billion years ago, an aerobic bacterium was engulfed by an anerobic host cell making a symbiotic relationship

  • over time the aerobic bacterium lost many genes and abilities and developed into today’s mitochondria

  • Photosynthetic cyanobacterium were engulfed by a host cell and overtime evolved to the chloroplasts

• Evidence - similarities between mitochondria/chloroplasts and prokaryotes

  • Both have/do: small circular DNA, 70S ribosomes, replicate via binary fission

  • also mitochondria and chloroplasts have outer and inner membrane

• Eukaryotic cell: Endosymbiosis helps explain how eukaryotic cells acquired mitochondria and chloroplasts.

Cytoskeleton

a network of elongated proteins in the cytoplasm with multiple functions

• functions: providing cell - shape, structure, movement, transportation, and biosignaling

3 major components of the cytoskeleton

• microfilaments: smallest, made of thin rods of repeating actin proteins

• intermediate filaments: intermediate in size, made of variable proteins

• microtubules: largest, forming tubes made of repeating tubulin proteins

Nucleus

• stores DNA

• Protein secretion starts here

• round structure that contains and protects most of an eukaryotic cell’s DNA

Parts of the Nucleus

• Nuclear envelope: double membrane that surrounds the nucleus and acts as a barrier

• Nuclear Pores: tiny holes in the nuclear envelope that allows entry/exit of the nucleus

• Nucleolus: a small dense structure inside the nucleus where ribosomes are assembled

Eukaryotic cell - within nucleus*

Chromatin

• the complex of DNA and proteins making up chromosomes

Ribosomes

• build proteins

• non-membranous organelles

• use the translation process to make protein

• free floating or attached to another organelle (rough ER)

Endoplasmic reticulum

• membranous structures continuous with the nuclear envelope with multiple functions

Two types of Endoplasmic reticulum

• Rough ER

• Smooth ER

Rough ER

• closer to the nucleus

• rough ribosome coated surface

• newly built proteins fold and are modified in the ER

Smooth ER

• further from the nucleus

• smooth ribosome free surface

• synthesizes lipids and detoxifies drugs/poisons

golgi apparatus

• stack of flat membranous sacs

• responsible for processing; receive vesicles, modify vesicles, and repackages contents into vesicles for export

  • “cis” end = receiving end, “trans” end = shipping end

Plasma membrane

the membrane at the boundary of every cell that acts as a selective barrier, regulating the cell’s chemical composition

• made of phospholipid bilayer

• “cell membrane”

• “Skin of the cell”

• composed of phospholipids and proteins