NYS Living Environment / Biology Regents Review - Vocabulary

Unit One: Science of the Living Environment

• Terms:

  • Observation: What is seen or measured.

  • Inference: A conclusion based on observation or evidence.

  • Hypothesis: An untested prediction, stating both cause and effect in an "If-then" statement.

  • Theory: A broad explanation of natural events supported by strong evidence.

• Graphing

• Controlled Experiment: Compares results between two or more groups.

  • Experimental group: Group being tested or receiving treatment (e.g., new drug).

  • Control group: "Normal" group, identical to experimental group in every way except it does not receive the treatment (e.g., no drug, or given original drug/placebo).

  • Placebo: A sugar pill or "fake" treatment given to the control group.

  • Independent Variable: The variable being tested (e.g., new drug), plotted on the X axis of a graph.

  • Dependent Variable: The variable measured at the end of an experiment (the results), plotted on the Y axis of a graph.

• Characteristics of a good experiment:

  1. Repeatable with the same results.

  2. Large sample size/many test subjects.

  3. Performed for longer periods of time.

  4. Tests only one variable.

  5. Peer-reviewed and examined by several scientists to determine accuracy.

  6. Does not have to agree with the hypothesis.

  7. Objective: fair, unbiased, fact-based.

Unit Two: Characteristics of Living Things

• All living things must maintain homeostasis.

  1. Organisms carry out basic life functions to maintain homeostasis: nutrition, excretion, transport, respiration, growth, synthesis, and regulation.

  2. All life processes make up an organism's metabolism.

  3. Failure to maintain homeostasis causes disease and death.

• Nutrition:

  1. Autotrophs make their own food, while heterotrophs eat other organisms.

  2. Photosynthesis is carried out by plants, algae, and blue-green bacteria (autotrophs). Radiant energy from the sun is converted into bonds of sugar molecules. Photosynthesis mostly occurs in the chloroplast of plant cells.

     • Plants have stomates (small holes in leaves) for gas exchange, which are opened and closed by guard cells.

• Respiration: Organisms get energy by breaking the bonds of sugar molecules. The released energy is used to make ATP.

  1. Aerobic respiration requires oxygen and yields more ATP than anaerobic respiration.

  2. Anaerobic respiration in humans produces lactic acid which damages muscles.

  3. Photosynthesis and aerobic respiration are opposite reactions, important in cycling oxygen, carbon, hydrogen, and water through the environment.

• Transport:

  1. Diffusion: Movement of molecules from high to low concentrations; requires no energy (passive transport).

  2. Active Transport: Requires energy to move molecules from low to high concentration (against diffusion).

  3. Osmosis: Diffusion of water into or out of the cell. Cell swells in water and shrivels in salt water.

• Regulation: Coordination and control of other life functions.

  1. A stimulus is a change in the environment that you respond to.

  2. A neuron is a nerve cell.

  3. An impulse is the electrical signal carried by nerves. Neurotransmitters are chemicals that help carry the impulse.

  4. A hormone is a chemical signal secreted by glands (e.g., insulin, adrenaline, testosterone, estrogen).

  5. Receptor molecules are proteins on the cell membrane that receive signals from the nervous and endocrine system.

• Chemistry

  1. The most common elements in living things are Carbon, Hydrogen, Oxygen, and Nitrogen (CHON).

  2. Organic Compounds have Carbon AND Hydrogen (e.g., C6H{12}O6 is organic; H2O, CO_2, and NO are not). Organic molecules are also larger than inorganic molecules.

  3. Carbohydrates are sugars and starches made from simple sugars (like glucose) that supply energy.

  4. Lipids store energy and include fats, oils, and waxes. They are made from fatty acids and glycerol.

  5. Proteins are made from amino acids. Proteins also make hormones and many body and cell structures.

     • The SHAPE of proteins determines their function.

     • Four specific jobs of proteins:

       1. Make enzymes.

       2. Make receptor molecules on the cell membrane to receive chemical messages.

       3. Make antibodies.

       4. Make hormones.

     • Enzymes are catalysts that affect the rates of chemical reactions.

       • Lock and key model: one type of enzyme fits one type of molecule; change its shape and the enzyme will no longer work.

       • High temperatures cause proteins and enzymes to lose their shape.

  6. pH: The pH scale measures the strengths of acids and bases. A low pH (0-6.9) is an acid, a high pH (7.1-14) is a base, and 7 is neutral (water).

• Cells: The basic unit of life. All living things (except viruses) are made of cells. Must know the cell theory (all living things are made of cells).

  1. Must know the differences between plant and animal cells.

  2. Must know the following organelles: cell membrane, cell wall, nucleus, chloroplast, cytoplasm, ribosome, vacuole, mitochondria.

  3. The cell membrane is made of lipids and proteins and shows selective permeability. Only some molecules can pass through it (typically small molecules like water and oxygen). Large molecules (like starch or protein) need to be moved by active transport.

     • All cells have a cell membrane, including those with cell walls (plants, fungi, some bacteria and protists). The cell wall is mostly for protection; the cell membrane is needed to control movement into and out of the cell. The animal kingdom is the only kingdom that completely lacks cell walls.

• Classification:

  1. Organisms are classified mostly by evolutionary history. Those with common ancestors are grouped together.

  2. Kingdoms are large groups of related organisms (fungi, bacteria, protists, animals, plants).

  3. A species is able to successfully reproduce amongst its members.

  4. A scientific name comprises an organism's Genus and species.

Unit Two: Maintaining Homeostasis in the Human Body

• Organization:

  1. Cells are specialized into tissues.

     • Tissues are groups of cells specialized to do certain jobs. Examples of tissues include muscle tissue and nerve tissue.

     • Specialization or differentiation occurs because only some genes in the nucleus of a cell are “turned on”. Almost every cells has a complete set of genes, but on those needed for the cells particular job are active. So while a red blood cell has all the genetic information needed to make nerves cells, bone cells and skin cells, all those genes are turned off, and only the red blood cell genes are turned on.

  2. Tissues work together to form organs (heart, lungs, kidney).

  3. Organs work together in organ systems (digestive system, nervous system, etc).

• Digestive System:

  1. Food is broken down so that it is small enough to enter the body tissues/cells.

  2. The digestive system is a one way passage through the body that includes the mouth, stomach and intestines.

  3. Food is moved through the digestive system by muscular contractions (peristalsis).

  4. Food is broken down mechanically and chemically.

  5. Undigested food is eliminated as solid waste. This is not excretion.

• Transport/Circulatory System:

  1. Moves material (water, nutrients, hormones, wastes) through the body.

  2. Red blood cells carry oxygen. White blood cells fight disease.

  3. Plasma is the fluid of the blood. It transports everything except oxygen.

  4. Platelets clot the blood.

• Immune System:

  1. The job of the immune system is to protect the body against pathogens.

     • Types of pathogens include viruses, bacteria, and parasites.

  2. White Blood Cells are the main components of the immune system. Different w.b.c's have different roles.

  3. Antigens cause an immune response. Antibodies are proteins made by white blood cells to attack antigens. Each antibody attacks a specific antigen as determined by its shape.

  4. Be able to explain why your body's immune system rejects organ transplants.

  5. Blood type O is a universal donor; type AB is the universal acceptor.

  6. A vaccine is an injection of a dead or weakened pathogen. This causes the body to make antibodies against that pathogen.

     • Vaccines only prevent diseases. They are not cures.

  7. Antibiotics are drugs used to stop infections by bacteria. Antibiotics will not work against viruses.

• Respiratory System:

  1. Physical respiration (breathing) provides oxygen needed for chemical respiration (which releases energy from sugar).

  2. The diaphragm is the muscle that allows breathing to occur.

  3. You breathe faster when CO_2 builds up in the blood (not when you need oxygen).

  4. The alveoli are very important because it is here that the oxygen enters the blood and CO_2 leaves. The alveoli took like microscopic sacs surrounded by capillaries.

• Excretory System:

  1. Removes metabolic waste from your body.

  2. Your body excretes salt, water, urea and CO_2.

  3. Lungs excrete CO_2 and water and the skin excretes sweat.

  4. The kidneys filter waste from blood and reabsorb nutrients.

  5. The liver filters toxins and dead red blood cells from the blood.

• Skeletal Muscle System

  1. Know the function of bones, bone marrow, cartilage, tendons and ligaments.

  2. Muscles only pull and must work in pairs.

• The Nervous System

  1. The nervous system regulates your body along with the endocrine system.

  2. Know the three parts of the brain and what they do (cerebrum, cerebellum, medulla).

  3. The spinal cord controls reflexes and brings impulses from the nerves to the brain.

• Endocrine System:

  1. Regulates body along with nervous system. Slower but with longer lasting effects.

  2. The pancreas makes insulin and glucagon which control blood sugar.

  3. Adrenal glands make adrenaline when the body is under stress.

  4. Testosterone (male), estrogen and progesterone (female) are the sex hormones.

  5. Hormone levels are controlled by negative feedback.

• Interaction between Systems:

  1. Be able to explain how different systems of the body work together to maintain homeostasis.

     • Ex:

       • Nutrients from the digestive system are transported to cells by the circulatory system.

       • Wastes from respiration are removed by the excretory system.

       • The nervous and endocrine systems work together to control the body.

• Diseases and Disorders:

  1. Be familiar with different diseases and disorders, what causes them, and how they may affect the body. Don't fret about memorizing all of them. Typically the exam will ask you to name a disease and how its disrupts homeostasis.

  2. Diseases and disorders include: Heart attack, stroke, cancer, Down's syndrome, diabetes, cystic fibrosis, sickle cell anemia, diarrhea, ulcers, AIDS, goiter, scurvy, rabies, meningitis, pneumonia, asthma, bronchitis, appendicitis, cold, flu

  3. Causes of diseases (Pathogens):

     • viruses (AIDS, cold, flu, chicken pox)

     • bacteria (strep throat, food poisoning, syphilis)

     • fungus (athlete's foot, ringworm)

     • parasites (tapeworm, leeches)

     • genetic disorders (Down's Syndrome, sickle cell, cystic fibrosis)

     • environmental toxins (lead poisoning, radiation)

     • poor nutrition (Scurvy, goiter)

     • organ malfunction (heart attack, diabetes)

     • high risk behavior (smoking, drug use, exposure to sun)

Unit Three: Reproduction

• Asexual reproduction:

  1. Advantages: faster, easier

  2. Disadvantage: no variety. Offspring are the same as parent.

• Sexual reproduction:

  1. Advantage: variety

  2. Disadvantage: more time, effort and risk.

• Mitosis

  1. Asexual

  2. One division => two identical, diploid (2n) cells.

  3. Chromosome number in the daughter cells is the same as in the parent cell.

  4. Large organisms use mitosis for growth and healing. Simple organisms use it to reproduce.

• Meiosis

  1. Sexual reproduction

  2. One cell divides twice to make four DIFFERENT cells.

  3. All 4 cells are haploid (n) meaning they have half the number of chromosomes found in the parent cell.

  4. Makes gametes (sex cells). In humans 4 sperm cells or 1 egg and three polar bodies are produced each time meiosis occurs.

  5. Separates pairs of homologous chromosomes so that offspring get one chromosome of each pair from a different parent.

• Fertilization occurs in the fallopian tube. A fertilized egg is called a zygote and has a normal number of chromosomes (2n).

• The fetus develops in the uterus. Cells divide without becoming larger (cleavage). After a few days, cells begin to differentiate - that is they start to form different types of cells (nerve, skin, bone, etc). At this stage the embryo is very vulnerable to alcohol, drugs, etc because the important organs and systems are just starting to develop.

  1. See page 7 for more on differentiation.

Unit Four: Genetics

• Humans have 46 chromosomes, or 23 homologous pairs.

• Chromosome pairs carry alleles for the same trait. We all have two alleles for each gene - 1 from each parent, 1 on each member of the homologous pair.

• While genes determine our traits, the environment can affect expression of genes.

• Each chromosome has hundreds or thousands of genes. Each gene codes for a particular protein (1 gene=1 protein).

• DNA is made of 4 bases: ATCG. A three letter codon represents a specific amino acid. These amino acids are assembles into proteins.

• Base pairs: A-T, C-G (in RNA, A-U and C-G)

• RNA carries the genetic code to ribosomes. The ribosomes then synthesize protein.

• Changes to DNA are called mutations. They can only be passed on if they occur in reproductive cells (sperm or egg).

• All cells in the body contain the same genes. Only some of these genes are turned on (that is, your eye cells contain the instructions on how to make bones, but only the genes to make new eye cells are actually turned on). We do not yet know exactly why this happens.

• Selective breeding produces animals and plants with desired traits (disease resistance, larger fruit, more meat or milk, specific colors).

• Genetic engineering or gene splicing inserts genes of one organism into the genes of another. Enzymes are used to cut and copy the DNA segments. Bacteria are often used because they have no nucleus protecting their DNA and they reproduce very quickly, allowing large amounts of medicine (insulin) to be made.

  • The example of gene splicing you MUST know:

    • The gene to make human insulin was inserted into bacteria. These bacteria can now make insulin that is exactly the same as human insulin. This insulin is used by diabetics. This is safer than the cow and sheep insulin that were used in the past.

• New technologies (karyotyping, DNA fingerprinting) are making it easier to diagnose and treat genetic disease, though we cannot yet cure them.

• Genetic research has posed many ethical problems (ie right and wrong) that science alone cannot answer.

Unit 5: Evolution

• Basically states that modern species evolved from earlier, different species and share a common ancestor.

• Charles Darwin proposed that natural selection is the mechanism that causes species to change. The basic steps in natural selection are:

  1. Overproduction of offspring.

  2. Competition for limited resources.

  3. Survival and reproduction OR death.

• Organisms that are better adapted to their environment and able to reproduce successfully are considered "fit". Unfit organisms die, and their traits are eventually removed from the gene pool.

  • Evolutionary fitness has nothing to do with physical fitness. Stronger is not always better.

• Evolution is usually driven by a change in the environment.

• To evolve, variations must exist in a species BEFORE the environment changes. They do not get a trait just because it is needed.

• Variations exist primarily as the result of sexual reproduction and mutation.

• Species with more variation are better able to survive environmental changes.

• Gradualism is a theory that says change occurs slowly. Punctuated equilibrium is a theory that says evolution happens in quick spurts.

• Creation of new species usually requires geographic isolation which eventually results in reproductive isolation.

• Evidence in support of evolution comes from the fields of geology (fossil record and radioactive dating), genetics, biochemistry, anatomy and embryology (among others).

Unit 6: Ecology

• Understand how organisms interact with their environment (food webs, nutrient cycles).

• Energy is needed to keep an ecosystem going. The energy comes from the sun and is made usable by producers (plants and other autotrophs)

• Energy is passed on to other organisms in the form of food. Since all organisms must use energy for their own needs, most energy is lost before it can be passé to the next step in the food chain. As a result, organisms high on the food chain have less energy available to them and must have smaller populations.

• Environmental factors (air, water, light, temperature, pH, food, predators etc) determine which organisms can live in an ecosystem and how large the population can get.

  • The maximum size of a population is called the carrying capacity.

• There are many roles in an ecosystem (niche), but competition between species usually results in only one species occupying a niche at any one time. Often, organisms with similar needs will divide resources to reduce competition (ex: birds eat insects during the day, bats eat them at night).

• Know the basic processes of ecological succession.

• Human action (development, industrialization, pollution, farming, over hunting, overgrazing, clear cutting, introduction of foreign species, soil erosion) often has negative consequences for the ecosystem (and humans too).

• The negative effects humans have had on the environment are all mostly due to the increasing human population.

• Biodiversity refers to the variety of life on earth. As habitats are lost and species become extinct, biodiversity is reduced. This is bad because 1) ecosystems with low diversity take longer to recover from environmental changes and 2) we use organisms for many things such as food and medicine; by reducing biodiversity we are losing potentially valuable resources.

• Actions being taken by humans to reduce or repair damage to the environment include:

  1. Recycling wastes

  2. Conserving available resources

  3. Using cleaner resources (ex: solar over fossil fuels)

  4. protection of habitats and endangered species

  5. use of biological controls instead of pesticides and herbicides

  6. Farming native plants (ex: cocoa in the rainforest)

  7. Planting trees to replace those cut down.

  8. Rotating crops or planting cover crops to reduce soil loss.

• Know the following terms: producer, consumer, omnivore, herbivore, carnivore, predator, parasite, habitat, niche, population, community, ecosystem, biosphere, pollution, renewable resource

• For each of the following ecological problems, you should be able to identify the specific cause, their negative effects on the environment, and a way that people are trying to fix the problem:

  1. acid rain

  2. loss of habitat (ex: deforestation)

  3. loss of diversity

  4. global warming

  5. loss of ozone layer

  6. introduced species

  7. industrialization

State Lab: Diffusion Through a Membrane

• Part A

  • Made a model cell using dialysis tubing.

  • Put glucose and starch inside your "cell."

  • Put starch indicator (iodine) outside cell

  • What you saw: Inside of cell turned black because iodine diffused into the cell

• Part B

  • Looked at red onion cells under the microscope.

  • Add salt water to the onion cells.

  • Added distilled (pure) water to the onion cells.

  • What you saw: Salt water caused the onion cells to shrivel; Distilled water causes the cells to swell back to normal.

• Learned:

  • Small molecules can diffuse through a cell's membrane while larger molecules cannot

  • Indicators can be used to detect the presence of certain substances

  • Salt water causes water to diffuse out of a cell.

  • In pure water, water will diffuse into a cell.

State Lab: Beaks of Finches

• What you did

  • Used different "tools" to simulate variation amongst the beaks of Galapagos Island finches all competing for food (seeds).

• What you learned

  • Different environmental conditions (food) favored different species of finch, allowing some to survive and reproduce, but not others.

State Lab: Relationships and Biodiversity

• What you did

  • Compared 4 species of plants, based on structural (physical) and molecular (chemical and genetic) traits.

• What you learned

  • Species that are related share similar traits.

  • Different techniques (such as gel electrophoresis and paper chromatography) can be used to determine relationships between organisms.

  • Endangered species should be protected because they may offer benefits to humans.