Characteristics of Life
What is an autotroph?
Uses carbon dioxide, water, and solar energy to make their own food
What is a hypothesis?
A predicted, testable explanation for an observation
What is the intermolecular bond between water molecules called?
Hydrogen bonds
Which biological molecule provides cells with quick energy?
Carbohydrates
What is DNA shaped as?
Double helix
Which characteristic of life explains how populations change over generations?
Living things are adapted
What is the name of the group that does not receive the experimental treatment and is used for comparison?
Control group
What property allows water to absorb large amounts of heat without a big temperature change?
Water has a high heat capacity
Which biological molecules are made of amino acid monomers and include enzymes?
Proteins
State the templates that are used for transcription and translation
- Transcription: DNA
- Translation: mRNA
Describe an example of homeostasis
(answers may vary)
What is the difference between an independent and a dependent variable?
- Independent = variable that is deliberately changed by experimenter
- Dependent = measured variable that changes based on the independent variable
Why is water considered a good solvent for ionic compounds?
Water is polar, so its partial charges attract to each ion's charge, pulling the ions away from each other
- Polar phosphate head
- Two nonpolar fatty acid tails
Why is DNA replication considered semiconservative?
Each new DNA molecule contains one original strand and one new strand
Describe an example of a response to stimuli. Include both STIMULI and BEHAVIOUR
(answers may vary)
A student changes light intensity, temperature, and water availability in one experiment. Why is this a problem?
Multiple independent variables make results unclear
Describe why waterbugs can float on water
Water has a high surface tension due to its strong hydrogen bonds, allowing it to support the waterbug's weight.
How does the structure of phospholipids allow them to form cell membranes in watery environments?
Their polar heads attract to surrounding water, while their nonpolar tails attract to each other on the inside, "shielded" from the water
What is the difference between the function of DNA polymerase and RNA polymerase?
- DNA polymerase: Adds nucleotides to the daughter DNA strand; does not open the DNA double helix
- RNA polymerase: Opens the DNA double helix AND adds nucleotides to the newly formed mRNA strand
Describe the difference between growth and development
- Growth is the increase in the size and often the number of cells (PHYSICAL changes)
- Development is ALL the changes that take place between conception and death (can include growth, but also mental, emotional, spiritual, etc. change)
A biologist concludes that fertilizer increases crop yield after one trial. What is the flaw?
The conclusion was drawn without enough repetitions
Use cohesion and adhesion to describe why water can flow up a tree trunk so easily?
- Cohesion allows water molecules to stick to each other, so they move as a unit
- Adhesion allows water molecules to cling to the trunk, so they can move up the trunk easily
What is the difference between saturated and unsaturated fats, and how does this affect their physical state at room temperature?
- Saturated = no double bonds, pack tightly, solid at RT
- Unsaturated = Double bonded/kinked, do not pack tightly, liquid at RT
Why do purines only bond with pyrimidines, and not with each other?
To maintain a constant width in the DNA double helix, since purines are double-ringed and pyrimidines are single-ringed