Biology Midterm Units 1 and 2

what are the 8 steps of the scientific method?

Defining a problem

Making observations

Hypothesis

Experiment

Collecting Data

Analysis

Conclusions

Report

What must scientific problems be?

testable

What is a hypothesis?

an explanation for something that can be tested in the form of an educated guess

How many variables does an experiment test at once?

one

What is an experiment?

a series of steps that test the hypothesis by collecting specific information

What is an independent variable?

a condition that can be manipulated by scientists

What is a dependent variable?

the condition that is affected by the independent variable

What are controls?

the group that is the standard to compare the results against

What are constants?

anything that stays the same for every experiement

What is qualitative data?

research based on observation that does not include numerical data

What is quantitative data?

research that gives numerical data

Which system is the SI based on?

metric system

What does mass measure?

the weight or how much matter is in an object

What are the units and tool used to measure mass?

Units- grams

Tool- Balance scale

What does length measure?

the distance between 2 points

What are the units and tools for measuring length?

Units- Meters

Tools- Meter stick or ruler

What does temperature measure?

the amount of heat in an object

What are the units and tool for measuring temperature?

units: celcius

tools: thermometer

What is the purpose of a graph?

to create a visual of information gathered in an experiment

What do line graphs show?

The relationships between two variables that are changing

What do scatterplots show?

a relationship between 2 variables (numbers)

What do bar graphs show?

a relationship of categorical data

What do pie charts show?

proportional relationships as parts of a whole

What is a data table?

a record of experimental data

Where do each variables go on the x- axis and the y-axis?

independent- x-axis

dependent- y-axis

If your data supports your hypothesis, what should you do next?

re-test to make sure results are consistent

If you data does not support your hypothesis, what should you do next?

re-test with new conditions to find an answer to the initial problem

What is a theory?

a hypothesis that has been supported by many scientists over time

What is a law?

a fact of nature generally known to be true

True or False- Organisms can be BOTH single cellular or multi cellular.

True

What are cells?

the most basic unit of life

What does energy give the ability to do?

change or do work

What is metabolism?

The chemical process of making or breaking molecules

What do organisms respond to?

stimuli (like light, temperature, and touch)

What does the stimuli responses help with?

homeostasis

What is homeostasis?

maintaining consistent internal conditions

What is the genetic material that is passed on called?

DNA

How do single cellular organisms reproduce?

one cell divides into two, both new cells are identical

How do multicellular organisms reproduce?

combining genetic info from both parents

What is a system?

an organized group of parts that relate to form a whole

What does it mean when we say that structure and function are related?

That what something does in an organisms is related to it’s shape or form

ex: lion teeth are different than human teeth because of the food that they eat

How is homeostasis maintained?

feedback, this compares the ideal condition to the actual condition to allow the organism to respond

What happens when homeostasis isn’t maintained after a long period of time?

lasting damage

What is evolution?

the change in living things over time or a long-term response to the environment

What happens as organisms adapt to survive in a specific environment?

They become more diverse and the traits and inherited from generation to generation

What is ethics?

belief system of what is right or wrong

How has technology impacted how we do science?

new experimental techniques, computers, wifi, microscopes, MRIs, robotics

What is biotechnology?

application of scientific research in living organisms or biological processes in new technological developments

What is an atom?

basic building block

What are the 5 CHONP elements?

carbon, hydrogen, oxygen, nitrogen, phosphate

What are covalent bonds?

very strong bonds that hold molecules together

What percentage of water do organisms contain?

70-95%

What does it mean when we say that water is a polar molecule?

it has separated areas of positive and negative charges

Water forms hydrogen bonds. What kind of bonds are these?

weak bond, proteins also rely on these to form complex shapes

How is there surface tension on water?

there are hydrogen bonds across the surface, the hydrogen bonds pull every water molecule tightly together

Is water more or less dense as a solid?

Less, this helps it float

Why is water called the universal solvent?

it can dissolve almost anything

What is a solute?

the dissolved molecule

What is a solvent?

the one doing the dissolving (you dissolve in the solvent)

What does it mean to be soluble?

the solute is able to be dissolved

What does it mean to be insoluble?

the solute is not able to be disso,ved

What does concentration show?

the amount of solute dissolved in the solvent, usually measured in grams per liter

ex: vitamin c dissolved in your blood

What does pH measure?

the concentration of hydrogen ions in a solution

What is the pH levels for acids?

0-6.99 pH

Are there lots or little hydrogen ions in acids?

lots

How does acid taste and what is an example?

tastes sour

lemon juice, stomach acid, vinegar

What are the levels of pH for bases?

7\.01-14 pH

are there lots or little hydrogen ions in bases?

little

How would bases taste and what are some examples?

taste bitter

detergent, ammonia, hand soap

What is water’s pH?

7 (neutral)

this means it will break apart when mixed with other substances to form either acids or bases

What are buffers and why are they important?

solutions that resist changes in pH, they are important because they help maintain homeostais

What do enzymes function as?

catalysts to lower activation energy

Where do enzymes work best as, and what happens in the wrong environment?

specific environments, like a specific pH or temp

in the wrong environments, they will unfold

What holds a folded protein together?

hydrogen bonds

What are reactions?

old substances that are changed into new substances

What is used to represent a reaction?

a chemical formula

What do all chemical reactions require a change in?

energy

What does an exothermic graph show?

a release in heat/energy

What does endothermic graph show?

an absorbtion of heat/energy

Organic molecules are substances that contain which element?

carbon

What is the basic unit of each organic compound called?

a monomer

What are larger molecules that formed from many monomers called?

polymers

What are elements for proteins?

C, H, O, N

What is the function of proteins?

signaling, structure, chemical reactions

What is the monomer of proteins?

amino acid

What is the polymer of proteins?

protein

structural: keratin, collagen

functional: enzymes, hemoglobin

What are the elements for carbohydrates?

C, H, O

What is the function of carbohydrates?

quick energy, structure

What is the monomer for carbohydrates called?

monosaccharides

(glucose, fructose)

what is the polymer (2 saccharides) for carbohydrates?

disaccharides

(sucrose, lactose)

what is the polymer (many saccharides) for carbohydrates?

polysaccharides

(starch, glycogen, cellulose)

What are the elements for lipids?

C, H, O

What is the function for lipids?

signaling, structure, energy storage

What is the monomer of lipids called?

fatty acid and glycerol

What is the polymer of lipids called?

lipid

(fats, oil)

What are fats composed of?

a glycerol and 3 fatty acid chains

What are saturated fats?

fats that are solid at room temp

ex: butter

What are unsaturated fats?

fats that are liquid at room temp

ex. olive oil

What are the elements for nucleic acid?

C, H, O, N, P

What is the function of nucleic acid?

genetic information