Science Semester 1 Final Flashcards
(102 cards)
1
Q
Exponential Growth
A
Populations grows without limit. Ex: human population.
2
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Logistic Growth
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Population grows quickly at first and then levels off. Ex: most natural populations (fish, rabbits, trees, etc.)
3
Q
Carrying Capacity
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The theoretical maximum population that a given environment could support.
4
Q
Limiting Factor
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Aspects of the environment that limit the size a population can reach
5
Q
Density-Dependent Limiting Factors: Definition and Examples
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Limiting factors that can be triggered by an increase in population size and thus crowding. They operate more strongly on large, dense populations than on smaller ones. Ex: Competition, Predation, Parasitism, Disease
6
Q
Density-Independent Limiting Factors: Definition and Examples
A
Limiting factors that regulate population growth regardless of its size or density. Nearly all species in an ecosystem are affected equally by density-independent limiting factors. Ex: Weather Changes, Pollution, Natural Disasters
7
Q
Habitat
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The actual area in the ecosystem where an organism lives, including all of its abiotic and biotic resources. Many organisms share a habitat.
8
Q
Niche
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All the things an organism needs and does within its habitat - It’s “job” in the ecosystem. Each organism has its own niche.
9
Q
Interspecific Competition
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Where competition is occurring between different species
10
Q
Intraspecific Competition
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Where competition is occurring within the same species
11
Q
Competitive Exclusion Principle
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No two organisms can occupy the same niche at the same time. If the organisms are very different, one is probably a better fit than the other. If the organisms are similar, it will take a fight to see who will win. The loser will have to find a different niche to occupy.
12
Q
Mutualism
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Both organisms involved benefit. Helps both organisms survive.
13
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Commensalism
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One organism is benefited while the other is unaffected (neither benefited nor harmed).
14
Q
Parasitism
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One organism (parasite) benefits from the relationship, while the other organism (their host is harmed). However, it is crucial the parasite doesn’t kill the host, so that the parasite can survive and spread.
15
Q
Competition
A
A relationship that exists between two or more organisms that are fighting for the same resource
16
Q
Interspecific Competition
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Where competition is occurring between different species
17
Q
Intraspecific Competition
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Where competition is occurring within the same species
18
Q
What are the three principles of cell theory?
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All living things are composed of one or more cells. Cells are the basic units of structure and function in an organism. Cells only come from existing cells.
19
Q
Robert Hook
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Scientist who observed cells in cork. Coined the term “cells”.
20
Q
Anton van Leeuwenhoek
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Scientist who created a powerful microscope and discovered bacteria
21
Q
Robert Brown (2)
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Scientist who noticed that pollen grains in water moved around - motion is called “Brownian motion”. Discovered the nucleus
22
Q
Matthias Schleiden
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A botanist who concluded that all plants are made of cells.
23
Q
Theodor Schwann
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A zoologist who concluded that all animals are made of cells
24
Q
Rudolph Virchow
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A physician who concluded all cells come from pre-existing cells.
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Differences Between Prokaryotic and Eukaryotic Cells (5)
Prokaryotic: No nucleus. No membrane-bound organelles. Division is binary fission. Small and unicellular. Have cell walls made of peptidoglycan.
Eukaryotic: Yes nucleus. Yes membrane-bound organelles. Division is mitosis. Larger unicellular or multicellular. Only fungi and plants have cell walls (made of chitin or cellulose).
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Similarities Between Prokaryotic and Eukaryotic Cells (5)
Cell membrane. Cytoplasm. Cytoskeleton. Ribosomes. Genetic Information (DNA or RNA).
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Cell Membrane (Plasma)
Animal, Plant, Prokaryote. Controls what goes in and out of the cell.
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Phospholipid Bilayer
Two layers of fats. The fats are phospholipids with hydrophilic heads and hydrophobic tails. Proteins embedded. Composed of many parts that move around freely.
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Cytoskeleton
Animal, Plant, Prokaryote. Give the cell shape. Can move organelles around. Provide structural support for animal cells (who don’t have a cell wall).
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Cytoplasm
Animal, Plant, Prokaryote. Holds everything in place. Provides a solution for chemical reactions to take place in.
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Nucleus
Animal, Plant. Protect the DNA that controls the activity of the cell.
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Nucleolus
Animal, Plant. Inside the nucleus. Make mRNA which make up ribosomes.
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Mitochondria
Animal, Plant. Structure: Where cellular respiration happens. Breaks down food to release energy. Powerhouse of the cell.
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Smooth Endoplasmic Reticulum
Animal, Plant. Job: Makes lipids (membranes). Destroys toxins (liver). Regulates calcium (muscles).
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Rough Endoplasmic Reticulum
Animal, Plant. Structure: Ribosomes on the surface. Hugs the nucleus. Job: Makes, transports, and modifies proteins.
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Ribosomes
Animal, Plant, Prokaryote. Make proteins!
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Golgi Apparatus
Animal, Plant. Gets vesicles of protein from ER. Vesicles are like mini-carts that transport proteins around the cell. Processes, sorts, and ships protein where needed.
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Vacuoles
Animal, Plant. Structure: Small and numerous in animal cells. One large central vacuole in plant cells. Job: Storage (water, nutrients, waste, etc.)
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Lysosomes
Animal. Structure: Contain enzymes. Job: Breakdown dead stuff (food, bacteria, old parts of cells, etc.). Can do programmed cell death (apoptosis).
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Cilia and Flagella
Animal/Prokaryote. Structure: Cilia - shorter, more numerous, like tiny oars. Flagella - longer, fewer. Job: Cilia - Move fluid across the cell surface. Flagella - move entire cell. NOT in all cells!
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Centrioles/Centrosomes
Animal. Appear during cell division (mitosis/meiosis). Help cells divide by pulling chromosomes apart.
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Chloroplasts
Plant. Where photosynthesis happens. Converts energy from sun to energy in sugar.
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Cell Wall
Plant, Prokaryote. Protect and maintain shape.
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Central Vacuole
Plant. Structure: One massive central structure. Job: Storage center.
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Facilitated Diffusion
A transport protein acts as a protein channel to help (facilitate) the diffusion of molecules that normally couldn’t pass across the cell membrane. Molecules move down a concentration gradient, from high to low concentration. Glucose and Sodium.
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Diffusion
The spreading out of molecules across a membrane until they are equally concentrated on both sides of the membrane. Molecules move down a concentration gradient, from high to low concentration. Oxygen and Carbon Dioxide.
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Osmosis
The diffusion of water across the cell membrane. Water molecules move down a concentration gradient, from high to low concentration.
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Hypertonic Solutions
Higher concentration of solutes within the cell compared to the outside environment. Water will move out the cell, down its concentration gradient. The cell shrivels (known as plasmolysis).
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Hypotonic Solutions
Higher concentration of solutes within the cell compared to the outside environment. Water will move into the cell, down its concentration gradient. The cell swells.
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Isotonic Solutions
Identical water concentrations to what is found in a cell’s cytoplasm. The cell stays the same.
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Endocytosis
A cell uses energy to important large amounts of materials INTO the cell using a vesicle.
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Exocytosis
A cell uses energy to export large amounts of materials OUT of the cell using a vesicle.
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Active Transport
Not all substances can move freely into or out of a cell. Some molecules have to be moved against the concentration gradient, from low to high concentration using ATP. Other substances are too big to move through a protein channel, and have to be enveloped or excreted from the cell.
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Molecular Pumps
When a cell uses energy to pump ions across the membrane through a protein channel. This allows a cell to concentrate key molecules within the cell or remove waste quickly from the cell.
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Homeostasis
The need of an organism to maintain and regulate constant or stable internal conditions. Much of homeostasis is maintained by the cell membrane controlling movement of things in and out of the cell.
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What happens during mitosis?
Prophase: Chromosome copies condense and are visible as sister chromatids. Nuclear membrane breaks down. Spindle fibers form out of centrioles.
Metaphase: Chromosomes line up in the middle of the cell. Spindle fibers connect to the centromere of each sister chromatid.
Anaphase: Sister chromatids separate, becoming individual chromosomes as chromatids move to opposite ends of the cell.
Telophase: Nucleus reforms. Chromosomes start to look like chromatin again (threadlike). Spindle fibers break down and dissolve.
Cytokinesis: Cytoplasm pinches in half, forming two cells.
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Cancer and the Cell Cycle
Cancer is uncontrolled cell division. Cancer cells divide much more frequently than healthy cells, causing tumors to be formed. It’s caused when regulation of the cell cycle breaks down.
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Tumor
Clumps of cells that divide uncontrollably. Two types: malignant and benign.
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What are the checkpoints of the cell cycle?
G1 Checkpoint: Checks for nutrients, growth factors, DNA damage. It decides if the cell should divide, delay division, or enter G0 resting phase.
G2 Checkpoint: Checks for cell size and DNA replication. If the cell is prepared, it triggers the start of Mitosis.
Mitosis Checkpoint: Checks for chromosome spindle attachment. Occurs during metaphase and triggers the exit of mitosis and cytokinesis and the beginning of G1.
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If a cell has 46 chromosomes, how many chromosomes would each new cell have after cytokinesis in mitosis? Why?
46 chromosomes. Mitosis results in two identical daughter cells.
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What are enzymes?
Enzymes are a type of protein that speed up biochemical reactions by lowering the activation energy. For this reason, and the fact that can be used over and over again, they are called catalysts,
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Activation Site
The place where the specific substrate bonds to the enzyme.
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Substrate
Substances that are changed during a reaction (reactants).
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Products
Substances that are made by a chemical reaction
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Activation Energy
The amount of energy needed to make a chemical reaction start
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Endergonic Reactions
Input energy. Products of an endergonic reaction store energy (absorb) in covalent bonds. More energy in products than reactants.
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Exergonic Reactions.
Release energy. Energy stored in covalent bonds are broken to release energy. Less energy in products than reactants.
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What are factors that affect the rate of a biochemical reaction? (3)
Temperature: Works best at body temperature, too high or too low can interfere with rate. pH: Most enzymes only work at very specific pH so if pH changes it can affect speed of the reaction. Concentration: More substrate or larger concentration of enzyme, the rate increases.
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Competitive Inhibitor
Inhibitors are chemical interference with an enzyme reaction. Resembles substrate and competes for active sites of an enzyme (blocks them). Interferes with active site of enzyme so the substrate can’t bind.
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Noncompetitive Inhibitor
Binds to enzyme in a different location. It changes the shape to the active site so the substrate can no longer bind to the enzyme.
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Producers
Obtain energy from nonliving sources to make their own food. Some must capture energy during photosynthesis to make simple sugars. Examples: plant, algae
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Consumers
Obtain energy from living or once-living organisms. Ex: Animals, fungus, people
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What two processes is photosynthesis made of?
Light-Dependent Reactions (Electron Transport Chain) followed by Light-Independent Reactions (Calvin Cycle)
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Photosynthesis: Electron Transport Chain Specific Process
Energy from sun is passed down the Electron Transport Chain and is stored in the bonds of ATP and NADPH. Light energy excites the electron. The electron moves down ETC.
At end they combine with of NADP+ and ADP, making NADPH and ATP. ATP, NADPH, and H+ leave the grana and go into the stroma for the next stage!
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Photosynthesis: Calvin Cycle Process
CO2 diffuses into stroma and 6-C molecules are produced. Energy from ATP and NADPH and an enzyme break the 6-C molecule into 2 3-C molecules (PGA) Each 3-C molecule (PGA) is converted to a different 3-C molecule (G3P). One G3P leaves the cycle to become glucose. The other G3P repeats the cycle.
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Photosynthesis: Electron Transport Chain - What goes in and what comes out?
Light and water go in. ATP, NADPH, and Oxygen come out.
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Photosynthesis: Calvin Cycle. What goes in and what comes out?
ATP and NADH (from ETC) and Carbon Dioxide go in. Sugar (glucose) comes out.
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Where does the Electron Transport Chain in photosynthesis take place?
Occurs in the grana (specifically the thylakoid membrane) where the chlorophyll is stored
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Where does the Calvin Cycle take place?
The Stroma
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Photosynthesis Reactants and Products
Reactants: Carbon Dioxide and Water
Products: Glucose and Oxygen
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Cellular Respiration Reactants and Products.
Reactants: Glucose and oxygen.
Products: Carbon Dioxide, Water, and ATP
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ATP Structure
Nitrogen base (adenine). Sugar base (ribose). 3 phosphate groups held together with high energy bonds.
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What processes is Cellular Respiration made out of?
Glycolysis then Krebs Cycle then Electron Transport Chain
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Glycolysis. Purpose. Location.
10-step process of splitting the 6-C molecule of glucose in half to form two 3-C molecules called pyruvate. This occurs in the cytoplasm and requires no oxygen, meaning it’s anaerobic.
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Krebs Cycle. Purpose. Location. What it Produces.
Make electron carriers NADH and FADH2 to move on to ETC. Located in the Mitochondrial Matrix. Produces a little ATP and releases carbon dioxide as a waste products.
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Cellular Respiration: Electron Transport Chain. What is it? What does it make? Where does it occur?
A series of reactions using the electrons and hydrogens carried by NADH and FADH2 in the Krebs cycle. Enzyme ATP Synthase helps to assemble ATP. Makes a ton of ATP as well as water! Located in the inner membrane of the mitochondria (cristae).
87
If there's no oxygen available, what process will cells go through to do cellular respiration?
Fermentation
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Lactic Acid Fermentation
Occurs in some bacteria and animal cells (like your muscles).Pyruvate from glycolysis is converted into lactic acid and 2 ATP
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Alcohol Fermentation
Occurs in yeast when oxygen is not available. Pyruvate from glycolysis is broken down into alcohol, CO2, and 2 ATP
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Primary Succession.
The ecological process by which plants and animals first colonize a barren area, such as a newly created or exposed landscape
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Secondary Succession.
A natural process that occurs when an ecosystem is disturbed, but not destroyed, and new species of plants and animals recolonize the area
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Pioneer Species
The first organisms to colonize an area
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What are the different parts of the cell cycle?
G1 (Gap/Growth 1): The cell grows and makes proteins.
S (Synthesis): Chromosomes replicate.
G2 (Gap/Growth 2): Cells continue to grow and make proteins.
Mitosis: Cells divide.
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Trophic Levels
The levels of nourishment in a food chain.
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Rule of 10 (Food Pyramid)
As energy flows from organism to organism, it is used for metabolism and/or converted to heat.
Because of this, the next organism on the chain only receives 10 PERCENT of the energy obtained in the previous level.
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Aerobic
Oxygen is present for the process
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Anaerobic
Oxygen is not present for the process
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Differences Between Plant and Animal Cells (3 Organelles Plants. 3 Organelles Animals.)
Plant cells have chloroplasts, cell wall, and a large central vacuole. Animal cells have centrioles/centrosomes, lysosomes, and sometimes cilia/flagella.
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What are the stages of the water cycle? (6)
Precipitation, Runoff, Infiltration/Percolation, Evaporation, Transpiration, Condensation
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What are the stages of the nitrogen cycle? (5)
Nitrogen fixation, decomposition, ammonification, nitrification, denitrification
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What are the stages of the phosphorous cycle? (5)
Weathering. Surface Runoff/Fertilizer Runoff. Decomposition. Sedimentation. Uplift.
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What are the stages of the carbon cycle? (6)
Photosynthesis, Cellular Respiration, Consumption, Combustion, Decomposition, Fossilization
