Fall Semester Exam Study Guide

What is the purpose of Science? To study the natural world and explain the nature of things (ex. how things work…)

What is a scientific theory? A theory is an explanation of a natural phenomenon that has been supported by many observations and experiments over time.

What would happen if new evidence contradicted a theory? The theory would have to be revised to fit the new evidence

What is the difference between quantitative and qualitative data? Quantitative deals with numbers or quantities Qualitative deals with descriptions of observations by our senses, ex. what does it look like?

What is an inference? Combining what you know with what you have learned to draw a logical conclusion

What are controls and independent and dependent variables? Controls are used for comparison and are not exposed to the experimental factor Independent variables are the tested factor, or what the scientist is manipulating in his/her experiment Dependent variables are the data, or the results that depend on the changes to the independent variable

What are the 8 characteristics of life Made of 1 or more cells Responds to stimuli Displays organization Requires energy Grows and develops Mantains homeostasis Reproduces Adaptations evolve over time

What is the difference between biotic and abiotic factors? Biotic – living Abiotic – non-living

What is the difference between food chains and food webs and what do they show? Food chains show a simplified single path for energy flow through an ecosystem Food webs show many interconnected food chains and pathways for energy flow throughout the ecosystem They show predator/prey and parasitic relationships Remember the arrow points in the direction of energy flow (towards who is doing the eating)

What happens if 2 species have overlapping niches? Competition – usually with one species being the winner (lives) and the other being the loser (dies)

Exponential is unlimited growth What is the difference between logistic and exponential population growth? Exponential is unlimited growth Logistic has limiting factors that make the population curve level off at carrying capacity

What type of biome has the greatest diversity of plant life? Tropical Rain Forests! (typically - The closer you get to the equator, the more diversity of life)

In the nitrogen cycle, what organism converts atmospheric nitrogen into a form that can be used by living things? Bacteria! Nitrogen-fixing bacteria live at the roots of some plants and convert nitrogen into a form that can be taken up by the plants, and then eaten by animals, etc.

In the phosphorus cycle, where is most of the phosphorus stored in the environment? Rocks

Excess nutrient runoff, like from agriculture or factories, can cause what disruption in bodies of water downstream? Harmful Algae Blooms

What is a chemical compound? When 2 or more elements chemically combine, such as h2o or CO2

What are the parts of an atom (& their charges and location) Neutron – neutral in nucleus Proton – positive in nucleus Electron – negative orbits around nucleus

A chemical bond in which electrons are shared What is a covalent bond? A chemical bond in which electrons are shared

What element do all organic molecules contain? carbon

What are the 4 main classes of biological macromolecules? Carbohydrates Lipids Proteins Nucleic acids

What are lipids and what are they made up of? Fats, oils, and waxes Made of fatty acids (long term energy storage and waterproof coating)

Carbohydrate – made up of simple sugars or monosaccharides What type of macromolecule is a starch such as glycogen? What monomer is it made up of? Carbohydrate – made up of simple sugars or monosaccharides Glycogen is broken down into glucose for energy

What is the monomer of a nucleic acid? What are 2 examples? Nucleotide DNA and rna

What are the products (substrates) and reactants in chemical reactions? Reactants  products

The amount of energy needed to start a chemical reaction What is activation energy? How does lowering the activation energy affect a chemical reaction? The amount of energy needed to start a chemical reaction Lowering the activation energy makes the reaction happen easier or quicker – enzymes do this!

What are enzymes? What is meant by the “lock and key” model? Proteins that speed up chemical reactions by lowering the activation energy One enzyme for one specific reaction – they aren’t interchangeable

What are the differences between prokaryotic and eukaryotic cells? No nucleus nucleus cytoplasm

What are the functions of the following organelles: nucleus, rough endoplasmic reticulum, mitochondria, lysosome, chloroplast, cilia, flagella Nucleus – holds DNA Rough ER – transportation for proteins made at ribosomes Mitochondria – converts glucose into energy (ATP) Lysosome – cleans old worn-out parts of the cell Chloroplast – site of photosynthesis – converts sun’s energy into glucose Cilia and flagella – for movement (OR movement of stuff outside of the cell)

What are the principles of Cell Theory? Organisms are made of 1or more cells Cells are the basic unit of life Cells come from pre-existing cells

What happens to cells in hypertonic, hypotonic, and isotonic solutions What happens to cells in hypertonic, hypotonic, and isotonic solutions? If more solute is added to a solution, does it become more hypertonic or hypotonic?

What is the difference between active and passive transport What is the difference between active and passive transport? Give 3 examples of each and indicated what type of substances are transported.

In the “fluid mosaic model” how do the phospholipids and other substances move around within the plasma membrane?

What molecule is the energy source for cells? ATP

What macromolecule that we eat is broken down to make ATP? Carbohydrates are broken down into simple sugars such as glucose Glycogen is the form of carbohydrate stored in your body that can break down into glucose

What is the chemical equation that represents photosynthesis?

Leaves have a large surface area exposed to the sunlight What organelle is the site of photosynthesis and why is it found primarily in leaves? Chloroplasts Leaves have a large surface area exposed to the sunlight

What is the pigment that captures sunlight during photosynthesis? chlorophyll

What is the chemical equation that represents cellular respiration?

The reactants of one are the products of the other What is the relationship between the products and reactants in those 2 equations? Opposites! The reactants of one are the products of the other

What are 3 factors that limit cell size? Getting enough nutrients Expelling enough wastes Transport of substances (high surface area to volume ratio in small cells is beneficial)

Describe the main events that occur during interphase. Growth and normal cell functions DNA replication Checking dna and preparing to divide

What happens during mitosis? What happens during each stage (PMAT)? Prophase – nuclear membrane disappears and chromosomes condense. Spindle begins to form (longest phase) Metaphase – chromosomes line up in middle (equator) (shortest stage) Anaphase – sister chromatids pulled apart Telophase – sister chromatids arrive at poles and new nuclear membranes appear

Uncontrolled cell cycle Rapidly dividing cells What is cancer? Uncontrolled cell cycle Rapidly dividing cells

What are sister chromatids? The two sides of the chromosome that contain identical copies of DNA, held together at the centromere

What is the difference between chromatin and chromosomes? Chromatin – relaxed version of DNA in interphase Chromosomes – condensed version of tightly coiled and packed dna that moves around during cell division

What makes the chromosomes line up at the equator or move around during mitosis? Spindle fibers attach to the centromeres and pull on chromosomes to move them where they need to go

How many chromosomes are in the 2 resulting daughter cells after mitosis and cytokinesis? The same number as the original cell In mitosis the daughter cells are genetically identical to the original cell, therefore if the original cell had 14 chromosomes, the daughter cells have 14 chromosomes

What is the main function of mitosis? To create identical cells to repair damaged cells or for organism growth