81 terms

Biology A

Chrissy's Biology A class study sheet.
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Biology
Study of life
Biodiversity
the variety of species that live in an area
Cells
Basic unit of life
Virus
A non-cellular infectious agent that has two characteristics
Biosphere
Consists of all life on Earth and all parts of the Earth in which life exists, including land, water, and the atmosphere.
Organism
anything that has or once had all the characteristic of life, any living thin a plant or animal
Adaptation
A trait that helps an organism survive and reproduce
Homeostasis
The maintenance of constant internal conditions in any organism.
Species
A particular type of living thing that can reproduce by interbreeding among themselves
Evolution
Change in a kind of organism over time; process by which modern organisms have descended from ancient organisms
How are species related to the concept of biodiversity?
More species live in warmer areas. They tend to have more diversity the closer they are to the equator.
How do the characteristics of living things contribute to an organisms survival?
All organisms must react to their environment. If they can adapt they will survive.
Describe the relationship between cells and organisms.
All organisms are made up of one or more cells.
You respond automatically to many different stimuli, such as loud noise why might a quick response to a sound be important?
It can warn you of approaching dangers.
Describe a biological system.
An ecosystem is a physical environment with different species that interact with one another and with nonliving things.
Why is homeostasis essential for living things?
Homeostasis is important because cells function best within a limited range of conditions.
What is the relationship between adaption and natural selection?
They both rely on the changing of the genetic make up to change.
How are structure and function related to adaption?
Adaptation can involve an adjustment to structure or function, so an organism will become more suited to an environment.
How is the process of natural selection involved in evolution?
It is the change in the genetic make up.
Do you think homeostasis is necessary at the level of a single cell.
Yes, even if its early the cell still needs to regulate itself to ensure proper balance.
In general greater biodiversity exists closer to the earths equator than in areas closer to Earths poles. what does this mean in terms of the number of species that are found in these regions.
This means there are many more kinds of species. The number of species is higher than other regions.
Briefly describe the basic characteristics that all living things on Earth have in common.
1. Cells- the basic unit of life
2. Organization- even single celled organisms are highly organized
3. Energy Use- all living things use energy in a process called metabolism
4. Homeostasis- maintaining stable internal conditions
5. Growth- result of cell division and enlargement
6. Reproduction- either sexual or asexual
7. Response- receptors receive stimuli and organisms respond to them, often through behavior
Give an example of how structure and function are related in an organism.
The structure and function relate because what the structure is made of influences what the organ's function is. An example is that the heart is made of strong muscle cells. Therefore, it is fit to do the job of pumping blood around the body
Explain how scientists use observation and data to develop a hypothesis.
scientist use observation and data by using common knowledge of all the things they already know. They can make an inference as to why something has happened.
What is the difference between a hypothesis and a theory?
A hypothesis becomes a theory when it has been tested and accepted.
How could banning DDT be beneficial to human health?
DDT is suspected to cause cancer.People living in areas where DDT is used for IRS have high levels of the chemical and its breakdown products in their bodies. So without DDT There might be less cancer.
Suppose a scientist is investigating plant growth. During the experiment, both type of light and the type of plant are manipulated. The scientist concludes that the results are caused by only changes in the light. Is this an appropriate conclusion? Why? or Why not?
No, because they don't know which changes are cause by the light and which changes are caused by the type of plant.
Cell membrane
A cell structure that controls which substances can enter or leave the cell.
Phospholipid
A molecule that is a constituent of the inner bilayer of biological membranes, having a polar, hydrophilic head and a nonpolar, hydrophobic tail.
Receptor
Is a protein that detects a signal molecule and performs a reaction.
Golgi apparatus
A system of membranes that modifies and packages proteins for export by the cell
Endoplasmic reticulum
A cell structure that forms a maze of passageways in which proteins and other materials are carried from one part of the cell to another.
nucleus
Control center of the cell
mitochondria
Enclosed by two membranes with the inner membrane folded; contains its own DNA
cell wall
A thin membrane around the cytoplasm of a cell.
chloroplasts
A structure in the cells of plants and some other organisms that captures energy from sunlight and uses it to produce food.
cytoskeleton
A network of long protein strands in the cytosol that helps support the cell
Prokaryotic cells
Do not have a nucleus or other membrane-bound organelles. They are also single celled organisms
Eukaryotic
Have a nucleus and other membrane-bound organelles. They can be multi celled or single celled
Passive Transport
Requires NO energy, Movement of molecules from high to low concentration, Moves with the concentration gradient
Diffusion
Movement of molecules from an area of higher concentration to an area of lower concentration.
Why do phospholipids form a double layer?
Phospholipids form a double layer in response to the presence of polar water molecules surrounding them.
Explain how membrane receptors transmit messages across the cell membrane
Membrane receptors are activated when a certain chemical attaches itself to the receptor. The receptor opens up and allows certain ions in through it's receptor channel into the cell. (sodium,potassium, ect) When an increased amount of sodium enters the cell, the cell depolarizes.
Describe the similarities between enzymes and receptors
Both enzymes and receptors have specific sites for the substrates. to bind. the receptor causes a response beyond the cell membrane and the enzyme facilitates a chemical change in the substrate.
Explain what concentration gradient is and what it means for a molecule to diffuse down its concentration gradient
The difference in the concentration of a substance from one location to another is a concentration gradient!
Explain why facilitated diffusion doesn't require energy from a cell.
The cell has proteins in the cell membrane, that are just essentially hollow tubes, that selectively filter molecules based on just size and/or charge of the molecule.
A cell is bathed in fluid. However, you notice that water is flowing out of the cell in what kind of solution is this cell immersed : isotonic, hypotonic, or hypertonic?
If water is flowing out of the cell then the water outside the cell has more nutrients. Therefore the solution outside the cell is hypertonic to the cell; it is the solution with a higher concentration. The cell would be hypertonic
Active Transport
Energy-requiring process that moves material across a cell membrane against a concentration difference
Endocytosis
The process of taking liquids or fairly large molecules into a cell by engulfing them in a membrane.
Exocytosis
Process by which a cell releases large amounts of material
Phagocytosis
process in which phagocytes engulf and digest microorganisms and cellular debris "CELL EATING"
How do transport proteins that are pumps differ from those that are channels?
Channels, when they open, just allow the molecule to pass through. With a pump, it requires energy, and will move it in a certain direction.
How do endoycytosis and exocytosis differ from diffusion?
Endocytosis and exocytosis involve taking something into the cell (endo) or removing it from the cell (exo), but it doesnt move across the membrane via diffusion, it requires energy and is either taken in as a little membrane bound package, or removed.
Small lipid molecules are in high concentration outside a cell they slowly cross the membrane into the cell. What term describes this action? Does it require energy?
diffusion is the movement of a molecule from high concentration to low concentration - it takes no energy, it just does it :) (i always think of it like when someone sprays perfume and it spreads across a room)
Ions are in low concentration outside a cell they move rapidly into the cell via protein molecules. what term describes this action? Does it require energy
Active Transport, Yes. (It is as if you have to swim upstream= use of energy.)
Cell theory
(biology) the theory that cells form the fundamental structural and functional units of all living organisms
ATP
(adenosine triphosphate) main energy source that cells use for most of their work
ADP
(Adenosine Diphosphate) The compound that remains when a phosphate group is removed from ATP, releasing energy
How are ATP and ADP related?
ADP stands for adenosine diphosphate, ATP is adenosine triphosphate. The difference being di- to tri-. ADP is missing a phosphate compared to ATP.
Chemosynthesis
Process by which some organisms, such as certain bacteria, use chemical energy to produce carbohydrates
What types of molecules are broken down to make ATP? Which are most often broken down to make ATP?
carbohydrate, lipids, or proteins can be broken down to make ATP. carbohydrates are the molecules most commonly broken down to make ATP.
How are some organisms able to survive without sunlight and photosynthesis?
Some organisms are able to extract their cellular energy from chemicals in their surroundings rather than from sunlight. Examples are tube worms living around thermal events in the deep ocean bottom.
Photsynthesis
The conversion of light energy into chemical energy stored in organic compounds (sugar).
Chlorophyll
Green pigment in plants that absorbs light energy used to carry out photosynthesis
thylakoids
A flattened membrane sac inside the chloroplast, used to convert light energy to chemical energy.
What are the roles of chloroplasts and chlorophyll in photosynthesis
Chlorophyll absorbs the sunlight, which allows the plant to obtain energy from the light
Chloroplasts are the organelles in a cell where chlorophyll is stored
Describe the stages of photosynthesis. Use the terms thylakoid, light-dependent reactions, and light-independent reactions in your answer
Within the thylakoid membrane is a chemical called chlorophyll, which absorbs and traps the sun's light for use in the process of photosynthesis. Photosynthesis occurs in two stages, called the light-dependent stage, and the light-independent stage.
Photosystem
A light-capturing unit located in the thylakoid membrane of the chloroplast or in the membrane of some prokaryotes, consisting of a reaction-center complex surrounded by numerous light-harvesting complexes. There are two types of photosystems, I and II; they absorb light best at different wavelengths.
Electron transport chain
A sequence of electron carrier molecules (membrane proteins) that shuttle electrons during the redox reactions that release energy used to make ATP.
ATP synthase
Large protein that uses energy from H+ ions to bind ADP and a phosphate group together to produce ATP
Calvin cycle
reactions of photosynthesis in which energy from ATP and NADPH is used to build high-energy compounds such as sugars
How do the two photosystems work together to capture energy from sunlight
In the first stage, light-dependent reactions or light reactions capture the energy of light and use it to make energy-storage molecules. During the second stage, the light-independent reactions use these products to capture and reduce carbon dioxide
Explain the relationship between the light-independent and the light-dependent and the light independent reactions
The products of the light-dependent reactions are used to help 'fuel' the light-independent reactions.
Explain how the calvin cycle is a bridge between carbon in the atmosphere and carbon based molecules in the food you eat
The Calvin cycle is a carbon dioxide gas from the atmosphere and the energy carried by ATP and NADPH to make simple sugars.
Explain why the chemical equation for photosynthesis is a highley simplified representation of the process how is the equation accurate how is it inacurate?
C6H12O6 + 6O2 --> 6CO2 + 6H2O = balanced photosynthetic reaction
Explain how both passive transport and active transport are necessary for photosynthesis to occur.
Passive transport is Transport of a substance across a cell membrane by diffusion. Active transport is the transport where there is an uptake of mineral or any substance against the concentration gradient.
How are cellular respiration and glycosis related?
Cellular respiration is the process of oxidizing food molecules, like glucose, to carbon dioxide and water.glycolysis, the breakdown of glucose to pyruvic acid.
Summarize the aerobic stages of cellular respiration be sure to discuss the Krebs cycle and the electron transport chain in your answer
Cellular respiration is the set of the metabolic reactions and processes that take place in the cells of organisms to convert biochemical energy from nutrients into adenosine triphosphate (ATP), and then release waste products. Aerobic and anaerobic forms of this process exist and are utilized in cells.
Describe the relationship between cellular respiration and photsynthesis discuss the functions of chloroplasts and mitochandria
Cellular respiration and photosynthesis have the same exact chemical formulas, except that the results of one are the products of the other.
what is the role of pyruvate in cellular respiration
The function of pyruvate in cellular respiration is to break down the two sets of reactions acetyl-COA formation and Krebs cycle from glycolysis, The reaction begins when pyruvate enters the inner compartment of a mitchondrion. It becomes converted to carbon dioxide and an intermediate acetyl-COA.
Is oxygen necessary for the production of all ATP in your cells? Why or why not?
No.
Glycolysis doesn't need oxygen to produce ATP.