what is a control in an experiment? a group in a scientific experiment that serves as a reference...
TRANSCRIPT
Buchholz High
SchoolEOC
ReviewBiology
What is a control in an experiment?•A group in a scientific experiment that serves as a reference for comparison to the experimental group.•A group that is untreated by the factor being tested.
Steps of Scientific Method
Sample Item 1: An osmosis investigation was conducted using chicken eggs to represent cells with semipermeable membranes. The mass of each egg was measured to determine how much water diffused into or out of the eggs. The eggs were first soaked in vinegar to dissolve the shell. Each egg was then placed in one of three different solutions for 24 hours. The table below show the results of the investigation.
OSMOSIS IN CELLS
Solution Average Mass of Eggs Before Soaking (grams)
Average Mass of Eggs After Soaking (grams)
Difference in Average Mass (grams)
Percent Change in Average Mass
Vinegar(95% Water)
71.2 98.6 27.4 +38.5
Corn Syrup(5% water)
98.6 64.5 34.1 -34.6
Distilled Water (100% water)
64.5 105.3 40.8 +63.3
Based on this experiment, which of the following should be inferred about cells with semipermeable membranes?A. Substances other than water may also cross the cell membrane.B. Substances other than water may block pores in the cell membrane.C. Water enters the cell when placed in environments of high water
concentration.D. Water leaves the cell when placed in environments with a low
concentration of solutes.
Microscopes Compound VS Electron
Compound Light Microscope: uses light to illuminate a specimen that is then magnified by two lenses.
Scanning Electron Microscope: (SEM)produces an enlarged, three-dimensional image of an object by using a beam of electrons rather than light.
Transmission Electron Microscope: (TEM) transmits a beam of electrons through a very thin slice of specimen and that can magnify up to 200,000 times
Staphylococcus aureus
MRSA
Theory of Evolution: (Darwin)A cumulative change in characteristics of organisms or populations over time from generation to generation.
Mendel's Law of Genetics: (Law of segregation) states that the pairs of homologous chromosomes separate in meiosis so that only one chromosome from each pair is present in each gamete.
Theory VS Law
Cell Theory: The theory that states that all living things are made up of one or more living cells, that cells are the basic units of organisms, that each cell in a multicellular organism has a specific job, and that cells come only from existing cells.
Cell Theory
Sample Item 2: The cell theory was first proposed in 1838. Evidence obtained through additional scientific investigations resulted in the current cell theory. Which statement describes a component of the original cell theory that was removed because of the new scientific knowledge?
A. All living things are made of cells.B. All cells come from other preexisting cells.C. Cells form through spontaneous
generations.D. Cells are the basic structural and
functional units of life.
Plant Cell VS Animal Cell
Animal cellPlant cell
Prokaryotic VS EukaryoticProkaryote: A single-celled organism that has no nucleus and has no membrane-bound organelles;-Ex. Bacteria and archaea
Eukaryote: An organisms made up of cells that have a nucleus enclosed by a membrane, multiple chromosomes, and a mitotic cycle-Ex. Animals, plants, and fungiNOT bacteria
Active Transport: The movement of chemical substances, usually across the cell membrane, against a concentration gradient; requires cells to use energy.
Passive Transport: the movement of substances across a cell membrane without the use of energy by the cell.
Sample Item 3: There are some similarities between prokaryotic and eukaryotic cells. Which of the following structures is found in both prokaryotic and eukaryotic cells?
A. LysosomesB. MitochondrionC. NucleusD. Ribosome
PLANTS
Photosynthesis: the process by which plants, algae, and some bacteria use sunlight, carbon dioxide, and water to produce carbohydrates and oxygen.
Photosynthesis
Cellular Respiration: The process by which cells obtain energy from carbohydrates; atmospheric oxygen combines with glucose to form water and carbon dioxide.
Cellular Respiration
Transpiration: The process by which plants release water vapor into the air through stomata; also the release of water vapor into the air by other organisms.
Transpiration
ReproductionAngiosperm: a flowering plant that produces seeds within a fruit.
Gymnosperm: a woody, vascular seed plant whose seeds are not enclosed by an ovary or fruit.
Xylem: the type of tissue in vascular plants that provides support and conducts water and nutrients from the roots.
Phloem: in vascular plants, the tissue that carries organic and inorganic nutrients in any direction, depending on the plant’s needs.
Stems
Sample Item 4: Terrestrial plants have stomata on the surface of their leaves. A single stoma is surrounded by two guard cells that change shape in response to environmental factors and open or close the stoma. Which of the following best explains how the structure of leaf is used in processes that occur in the plant?
A. Water enters the plant through the surface of the leaf for transpiration.
B. Gases for photosynthesis are exchanged through the surface of the leaf.
C. Energy for cellular reproduction is absorbed through the surface of the leaf.
D. Carbon dioxide enters the plant through the surface of the leaf for cellular respiration.