Bio Midterm

Question 1

Explain the scientific method

Answer 1

a researcher develops a hypothesis, tests it through various means, and then modifies the hypothesis on the basis of the outcome of the tests and experiments

Question 2

What is the difference between an independent and dependent variable?

Answer 2

Independent variables are what we expect will influence dependent variables. A Dependent variable is what happens as a result of the independent variable.

Question 3

what is the difference between quantitative data and qualitative data?

Answer 3

Quantitative data refers to any information that can be quantified, counted or measured, and given a numerical value. Qualitative data is descriptive in nature, expressed in terms of language rather than numerical values.

Question 4

8 characteristics of living organisms

Answer 4

reaction, reproduction, evolution, regulation, homeostasis, and ability to create energy, at least 1 cell

Question 5

What is the difference between an autotroph and a heterotroph?

Answer 5

Autotrophs are known as producers because they are able to make their own food from raw materials and energy. Examples include plants, algae, and some types of bacteria. Heterotrophs are known as consumers because they consume producers or other consumers.

Question 6

6 elements in organic compounds? what is the acronym?

Answer 6

The acronym CHNOPS, which stands for carbon, hydrogen, nitrogen, oxygen, phosphorus, sulfur, represents the six most important chemical elements whose covalent combinations make up most biological molecules on Earth.

Question 7

what is the main function of each group of organic compound?

Answer 7

The carbohydrates are quick energy storage

The lipids are used to store energy for later usage.

The proteins are used to control the energy created

Question 8

Give examples of molecules from each group of organic molecules.

Answer 8

Examples of organic

Question 9

What are four classes of organic molecules?

Answer 9

There are four classes of organic molecules: carbohydrates, lipids, proteins, and nucleic acids

Question 10

how do enzymes affect chemical reactions?

Answer 10

Enzymes in our bodies are catalysts that speed up reactions by helping to lower the activation energy needed to start a reaction.

Question 11

Define catalyst..

Answer 11

A catalyst is a substance that speeds up a chemical reaction, or lowers the temperature or pressure needed to start one, without itself being consumed during the reaction. Catalysis is the process of adding a catalyst to facilitate a reaction

Question 12

how do factors such as enzyme concentration affect enzyme activity?

Answer 12

Enzyme concentration: Increasing enzyme concentration will speed up the reaction, as long as there is substrate available to bind to.

Question 13

how do factors such as temperature and pH affect enzyme activity?

Answer 13

Temperature: Raising temperature generally speeds up a reaction, and lowering temperature slows down a reaction. However, extreme high temperatures can cause an enzyme to lose its shape (denature) and stop working. pH: Each enzyme has an optimum pH range. Changing the pH outside of this range will slow enzyme activity

Question 14

Describe contributions of scientists to the development of cell theory

Answer 14

Credit for developing cell theory is usually given to three scientists: Theodor Schwann, Matthias Jakob Schleiden, and Rudolf Virchow. In 1839, Schwann and Schleiden suggested that cells were the basic unit of life. Their theory accepted the first two tenets of modern cell theory

Question 15

List the 3 parts of cell theory

Answer 15

The three parts of the cell theory are:

All living things are composed of cells.
Cells are the basic units of structure and function for living things.

All cells come from pre-existing cells. Also, organisms grow by “adding on more cells” NOT by increasing the size of their cells.

Question 16

Difference between prokaryotic cells and eukaryotic cells?

Answer 16

Prokaryotes are always unicellular, while eukaryotes are often multi-celled organisms. Additionally, eukaryotic cells are more than 100 to 10,000 times larger than prokaryotic cells and are much more complex. The DNA in eukaryotes is stored within the nucleus, while DNA is stored in the cytoplasm of prokaryotes.

Question 17

Difference between plant and animal cells

Answer 17

Plant cells have a cell wall, as well as a cell membrane. In plants, the cell wall surrounds the cell membrane. This gives the plant cell its unique rectangular shape. Animal cells simply have a cell membrane, but no cell wall.

Question 18

what is the process of diffusion in biology?

Answer 18

Diffusion is the movement of molecules from an area of high concentration of the molecules to an area with a lower concentration. The difference in the concentrations of the molecules in the two areas is called the concentration gradient

Question 19

what is the function of a cell membrane?

Answer 19

The cell membrane, also called the plasma membrane, is found in all cells and separates the interior of the cell from the outside environment. The cell membrane consists of a lipid bilayer that is semipermeable. The cell membrane regulates the transport of materials entering and exiting the cell.

Question 20

what is the difference between active and passive transport in biology?

Answer 20

Active transport requires energy for the movement of molecules whereas passive transport does not require energy for the movement of molecules. In active transport, the molecules move against the concentration gradient whereas in passive transport, the molecules move along the concentration gradient.

Question 21

describe the structure of a cell membrane

Answer 21

Biological membranes usually involve two layers of phospholipids with their tails pointing inward, an arrangement called a phospholipid bilayer. Cholesterol, another lipid composed of four fused carbon rings, is found alongside phospholipids in the core of the membrane.

Question 22

what are carrier and channel proteins?

Answer 22

Channel proteins are proteins that create hydrophilic holes in cell membranes, facilitating the transport of molecules down the concentration gradient. Carrier proteins are integral proteins that transport chemicals across the membrane both down and up the concentration gradient.

Question 23

what occurs in osmosis?

Answer 23

In biology, osmosis is the movement of water molecules from a solution with a high concentration of water molecules to a solution with a lower concentration of water molecules, through a cell’s partially permeable membrane.

Question 24

what is the difference between the impact of isotonic hypotonic and hypertonic solutions on animal vs plant cells?

Answer 24

If a cell is placed in a hypertonic solution, water will leave the cell, and the cell will shrink. In an isotonic environment, there is no net water movement, so there is no change in the size of the cell. When a cell is placed in a hypotonic environment, water will enter the cell, and the cell will swell.

Question 25

define crenate in biology

Answer 25

Noun. crenation (countable and uncountable, plural crenations) (biology) The contraction of, or formation of abnormal notchings around, the edges of a cell after exposure to a hypertonic solution, due to the loss of water through osmosis, especially noticeable in red blood cells.

Question 26

define lyse in biology

Answer 26

In biology, lysis refers to the breakdown of a cell caused by damage to its plasma (outer) membrane. It can be caused by chemical or physical means (for example, strong detergents or high-energy sound waves) or by infection with a strain virus that can lyse cells.

Question 27

Define ATP molecule

Answer 27

Adenosine triphosphate (ATP) is the source of energy for use and storage at the cellular level. The structure of ATP is a nucleoside triphosphate, consisting of a nitrogenous base (adenine), a ribose sugar, and three serially bonded phosphate groups.

Question 28

how is energy released from atp molecule

Answer 28

When one phosphate group is removed by breaking a phosphoanhydride bond in a process called hydrolysis, energy is released, and ATP is converted to adenosine diphosphate (ADP). Likewise, energy is also released when a phosphate is removed from ADP to form adenosine monophosphate (AMP).

Question 29

what is turgor pressure in biology

Answer 29

Turgor pressure is the hydrostatic pressure in excess of ambient atmospheric pressure which can build up in living, walled cells. Turgor is generated through osmotically driven inflow of water into cells across a selectively permeable membrane; this membrane is typically the plasma membrane.

Question 30

what is the purpose of photosynthesis biology?

Answer 30

Plants are autotrophs, which means they produce their own food. They use the process of photosynthesis to transform water, sunlight, and carbon dioxide into oxygen, and simple sugars that the plant uses as fuel

Question 31

what are the reactants and product of photosynthesis?

Answer 31

During photosynthesis, light energy converts carbon dioxide and water (the reactants) into glucose and oxygen (the products).

Question 32

what is the structure of a chloroplast?

Answer 32

Chloroplasts are oval-shaped and have two membranes: an outer membrane and an inner membrane. Between the outer and inner membrane is the intermembrane space approximately 10-20 nm wide. The space within the inner membrane is the stroma, the dense fluid within the chloroplast