Biology EOC study guide – Flashcards
Unlock all answers in this set
Unlock answersquestion
What is the study of Biology?
answer
The science that seeks to understand the living world. Studies molecules, cells, organisms, populations of a single organism, communities of populations living in the same area, and the biosphere.
question
Contrast unicellular and multicellular organisms.
answer
Unicellular only consists of a single cell, and multicellular organisms consist of many cells.
question
What is homeostasis? Give an example.
answer
Homeostasis is the process by which organisms maintain a relatively stable internal environment. Example: regulating body temperature.
question
What are the main characteristics of life?
answer
The main characteristics of life include: living things are made up of cells, living things reproduce, living things are based on a universal genetic code, living things grow and develop, living things use energy (metabolism), living things respond to their environment, living things maintain a stable internal environment, and living things change over time (groups change).
question
What are the steps of a scientific method?
answer
State the problem, research, form a hypothesis, experiment using variables, collect data, derive a conclusion.
question
How do scientists use the scientific method?
answer
Scientists follow the scientific method in all experiments performed to ensure proper results and data.
question
What are the purposes of using microscopes in science?
answer
Microscopes aid in magnifying images of structures that are too small to see with the unaided eye.
question
What is an element?
answer
An element is a substance consisting entirely of one type of atom.
question
What is an atom?
answer
An atom is the basic unit of matter.
question
What is a molecule?
answer
A molecule is the smallest unit of compounds.
question
What is a compound?
answer
A compound is a substance formed by the chemical combination of two or more elements in definite proportions.
question
Describe the atomic structure of an atom.
answer
An atom consists of protons, neutrons, and electrons. The protons(+) and neutrons (neutral) are formed in the nucleus. The electrons (-) orbit, or move around, the nucleus. The atomic number on the periodic table is determined by the number of PROTONS present.
question
Describe the different types of atomic bonding (covalent, ionic, hydrogen)
answer
Covalent bonds form when electrons are shared between atoms. Ionic bonds form when two or more electrons are transferred (lost or gained) from one atom to another. Hydrogen bonds (opposite charges) are the strongest bonds that can form between MOLECULES. Hydrogen bonds are the bonds present in a DNA molecule.
question
What are solutions?
answer
Solutions are a mixture of two or more substances in which the molecules of the substances are evenly distributed. Ex: Salt Water
question
What is the difference between a solvent and a solute?
answer
A solvent is a substance in which a solute is dissolved to form a solution. A solute is a substance that is dissolved in a solvent to make a solution.
question
What does "polarity" mean in regards to the properties of water?
answer
Polarity involves a substance that has a distinct positive end and a distinct negative end. Water is an example! Because it is polar, water molecules attract to other water molecules.
question
What are organic compounds?
answer
An organic compounds is any compounds that contains carbon. Organic chemistry is the study of these compounds.
question
What is the main function of ATP? How is ATP made?
answer
ATP provides and stores energy for many cellular processes. ATP is made when a single phosphorus is added to ADP.
question
What are three carbohydrates?
answer
Glucose, fructose(monosaccharides), galactose, disaccharides, and glycogen (polysaccharides). Elements: carbon, hydrogen, and oxygen in a 1:2:1 ratio. Monomers are monosarccharides.
question
What are the role of proteins and enzymes?
answer
Proteins are polymers of amino acid that control the rate of reactions and regulate cell process. Enzymes are catalysts (remain unchanged during the reaction) that speed up chemical reactions that take place in cells and break down certain substances. They speed up a reaction by lowering the activation energy.
question
What is a positive test for starch? Sugar? What indicator gives that response?
answer
A positive test for starch is a change in the appearance of iodine. Iodine turns black. Sugar is the change in the appearance of Benedict's solution- goes from blue to orange.
question
What is a positive test for lipids? What indicator gives that response?
answer
A positive test for lipids is clear spots on brown paper. (Think grease spots on your Fast Food bags!) Sudan IV- dark red to orange!
question
What is a positive test for proteins? What indicator gives that response?
answer
A positive test for proteins is a change in the Biuret reagent. It turns a blue color to a purple color when positive for proteins. Proteins include carbon, hydrogen, oxygen, and nitrogen. Monomers are amino acid.
question
What are lipids? Give an example of a lipid.
answer
Lipids are made mostly from hydrogen and carbon atoms (consist of glycerol and fatty acids) and can be used to store energy. Examples: Oils. Made of carbon, hydrogen, oxygen, nitrogen and phosphorus. Monomers are nucleotides.
question
Describe a prokaryotic cell in comparison to a eukaryotic cell.
answer
Prokaryotic cells do not contain a nuclei or other organelles, except cell membranes, cytoplasm, and DNA. (example:bacteria). Eukaryotic cells are much more complex, and they do contain a nucleus and organelles. (example:animals).
question
What is the cell theory?
answer
The cell theory states: all living things are composed of cells, cells are basic units of structure and function in living things, and new cells are produced from existing cells.
question
Why is the surface area-to-volume ratio important in cells?
answer
Changes in the surface area to volume ratio have important implications for limits or constraints on organism size (too large result in lack of nutrients, size and information overload, and excess of wastes) Cells splits into two cells to avoid this (mitosis)
question
List and describe the main organelles present in an eukaryotic cell.
answer
Cell Membrane: Doorway-allows substances in and out. Cytoplasm: Jelly-like substance inside a cell. Nucleus: Control center-brain. Nuclear Membrane: protects the nucleus. Mitochondria: powerhouse-source of energy. Endoplasmic Reticulum: transportation system. Ribosomes: protein factories Golgi bodies: post office- enzymes attach carbs Vacuole: storage tanks Lysosomes: clean up crew- break down substances. Cell Wall (plant): Fence-structure and support Chloroplast (plant): Energy Producers-photosynthesis.
question
What is the role of the plasma membrane? What does it mean to be selectively permeable?
answer
The plasma membrane regulates what leaves and enters the cell and also provides protection and support. If selectively permeable, the membrane only allows certain material to enter and leave the cell.
question
What are phospholipids?
answer
Make up the lipid bilayer. Phospholipids are fat derivatives in which one fatty acid has been replaced by a phosphate group and one of several nitrogen-containing molecules. They are amphiphlic molecule, meaning a portion can be dissolved in water and a portion that cannot dissolve in water.
question
Describe the fluid mosaic model.
answer
The fluid mosaic model states that the phospholipid bilayer behaves like a fluid more than it behaves like a solid. The membrane's lipids and proteins can move laterally within the bilayer, like a boat on the ocean.
question
What does the cell membrane have embedded proteins?
answer
The proteins help substances that can not easily pass through the membrane by allowing them to pass through protein channels (faciliated diffusion)
question
Describe multicellular organization (steps from cells to organisms)
answer
Cells to tissue to organs to organ systems.
question
What is passive transport? Give three examples.
answer
Passive transport involves the movement of substances across a cell membrane that does not require the input energy. Examples: diffusion, osmosis( movement from higher concentration to lower concentration, and faciliated diffusion.
question
Hypertonic:
answer
When the concentration of solute molecules outside the cell is higher than the concentration in the cytosol.
question
Hypotonic:
answer
when the concentration of solute molecules outside the cell is lower than concentration in the cytosol.
question
Isotonic:
answer
when the concentration of solutes outside and inside the cell are equal.
question
What is a concentration gradient?
answer
The movement of a substance from an area with a high concentration to an area of low concentration. In active transport, the substances move against the concentration gradient (move from low to high)
question
What does it mean to have equilibrium in a cell?
answer
Equilibrium is a stable situation in which forces cancel one another (no net movement in or out of cell) Think Isotonic!
question
Describe active transport. Give an example.
answer
In active transport the substances move across the concentration gradient (move from low to high) . Example: sodium/potassium pump.
question
Contrast autotrophs and heterotrophs.
answer
Autotrophs have the ability to capture energy from sunlight or chemicals and use it to produce its own food (also known as producers). Heterotrophs obtain their energy from the food it consumes (also known as consumers.)
question
What are the reactants and products in photosynthesis?
answer
The reactants of photosynthesis are carbon dioxide, water, and light. The product is sugar (glucose) and oxygen.
question
What are the roles of chloroplast in a plant cell?
answer
Chloroplasts use the energy from sunlight to make energy-rich food molecules in a process known as photosynthesis.
question
Distinguish between photosystems 1 and 11 in photosynthesis.
answer
Photosynthesis starts in photosystem 2 (light is absorbed and transfered to electrons. After photosystem 2, the process continues to photosystem 1 (electrons are picked up by NADP+ into the energy carriers ATP and NADPH.
question
What happens during the light reaction of photosynthesis?
answer
The light dependent reactions produce oxygen gas and convert ADP and NADP+ into the energy carrieres ATP and NADPH.
question
Describe the electron transport chain.
answer
High energy electrons move from photosystem 11 through the electron transport chain to photosystem 1.
question
What is the Calvin Cycle (dark cycle)?
answer
The Calvin Cycle uses ATP and NADPH from the light-dependent reactions to produce high-energy sugars. Need the addition of carbon dioxide!
question
Discuss the rate of photosynthesis.
answer
Many factors affect the rate of photosynthesis includes: water shortages, temperature, and intensity.
question
What are the reactants and products of cellular respiration?
answer
Reactants of cellular respiration include oxygen and glucose. The products are carbon dioxide, water and energy.
question
Describe the process of glycolysis.
answer
Glycolysis is the process in which one molecule glucose is broken in half, producing two molecules of pyruvic acid, a 3-carbon compound.
question
What is the difference between aerobic and anaerobic respiration?
answer
Aerobic respiration requires oxygen, and anaerobic respiration does not require oxygen.
question
What is the outcome of the Krebs Cycle?
answer
During the Krebs Cycle, pyruvic acid (Acetyl-CoA) is broken down into carbon dioxide in a series of energy-extraction reactions.
question
When does the process of fermentation take place? What are the two main types of fermentation?
answer
Fermentation takes place when oxygen is not present during glycolysis. The two main types of fermentation are alcoholic fermentation (yeast cells) and lactic acid fermentation (muscle cells)
question
Describe the structure of a DNA molecule. What are the components present?
answer
DNA molecules are a double-helix structure (winding staircase). DNA molecules consist of a chain of nucleotides, a sugar-phosphate backbone (covalent bonds) and hydrogen bonds holding the base pairs together.
question
The structure of a condensed chromosome.
answer
Chromosomes consists of 2 identical chromatids and a centromere.
question
What is a chromatin?
answer
Chromatin is DNA that is not condensed (in the nucleus).
question
What is the role of histones?
answer
Histones are globular protein molecules around which DNA is tightly coiled in chromatin.
question
Discuss the difference between sex chromosomes and autosomal chromosomes.
answer
Sex chromosomes determine the sex of a child (male or female). Autosomal chromosomes determine other traits (heredity).
question
What are homologous chromosomes?
answer
Chromosomes that each have a corresponding chromosome from the opposite-sex parent.
question
How is a karyotype useful in genetics?
answer
Karyotype are a set of photographs of chromosomes grouped in order in pairs. Are used to examine an individual's chromosomes.
question
Contrast a haploid cell verses a diploid cell.
answer
Haploid cells contain only a single set of chromosomes and therefore only a single set of genes. Diploid cells contain both sets of homologous chromosomes.
question
What is binary fission?
answer
Binary fission is a type of asexual reproduction in which a prokaryote replicates its DNA, and divide in half, producing two identical daughter cells. Budding is asexual reproduction.
question
Discuss the cell cycle (include G1, S, and G2.
answer
Series of events that cells go through as they grow and divide. G1=cell growth, S=DNA replication, G2=preparation for mitosis. All part of interphase.
question
What are the phases of mitosis?
answer
(interphase and cytokinesis-not a phase of mitosis!) Interphase in not a phase of mitosis!) Prophase, Metaphase, Anaphase, and Telpphase.
question
What are gametes?
answer
Specialized cells involved in sexual reproduction. Egg cells-oogensis. Sperm cells- spermatogensis.
question
What is crossing over? Where does it occur during the process of meiosis?
answer
Crossing over is the process in which homologous chromosomes exchange portions of their chromatids during prophase 1 of meiosis,
question
What is the difference between sexual and asexual reproduction?
answer
Sexual reproduction is the process by which two cells from different parents unite to produce the first cell of a new organism. Asexual reproduction is the process by which a single parent reproduces by itself.
question
Describe the study of genetics.
answer
Genetics is the scientific study of heredity.
question
Define: Heredity, dominant allele, recessive allele.
answer
Heredity is the genetic transmission of characteristics from parent to offspring. Dominant alleles mask the recessive alleles. Recessive will only show up-if dominant allele is not present~
question
What was Mendel's experiment? How did it determine traits passed from generation to the next?
answer
Mendel studied traits and gene transfer by cross-pollinating pea plants. He used Punnett Squares to determine the probability of traits being passed from one generation to another.
question
Discuss pollination (self vs. cross)
answer
Self-pollination includes only one plant that produces offspring identical to them. Cross-pollination is the fertilization of male sex cells in pollen from the flower on one plant with the egg cell of a flower on another plant (hybrid)
question
What are the P, F1, and F2 generations?
answer
P=parent generation. F1=first generation, F2=second generation.
question
Contrast homozygous and heterozygous.
answer
Homozygous is the term used to refer to an organism that has two identical alleles for a particular trait (TT or tt). Heterozygous is used to refer to an organism that has two different alleles for the same trait (Tt).
question
What is a genotype?
answer
Genotype is the genetic makeup of an organisms.
question
What is a phenotype?
answer
Phenotype is the physical characteristics of an organism.
question
Discuss the Law of Segregation (alleles)
answer
States that a pair of factors is segregated, or separated, during the formation of gametes.
question
What is the Law of Independent Assortment?
answer
states that each chromosome (or pair) separates independently of each other to form the gametes (egg and sperm)
question
How does probability help us understand the passing of traits from one generation to the next?
answer
It is simply the likelihood that a certain trait will be passed on to the next generation.
question
What are alleles? What is their function?
answer
Each of several alternative forms of a gene. Ex. AA or Aa, the individual A is an allele. AA is alleles for a gene.
question
What do Punett Squares determine?
answer
They aid in predicting the probability that certain traits will be inherited by offspring.
question
What is a monohybrid cross? Dihybrid crosses?
answer
A monohybrid cross involves the crossing of just one trait. Ex. AA x Aa. A Dihybrid cross involves crossing 2 traits. Ex. AABb x AaBB
question
What is the result of incomplete dominance?
answer
? A blending of the traits. Red flowers x White flowers = pink flower in heterozygous offspring
