Revision Test 1 (Cells and Scientific Communication)
Call Kai
Learn
Practice Test
Spaced Repetition
Match
Flashcards
Knowt Play1/234
There's no tags or description
Looks like no tags are added yet.
Name | Mastery | Learn | Test | Matching | Spaced | Call with Kai | Chat |
|---|
No analytics yet
Send a link to your students to track their progress
235 Terms
What are the six major elements of life?
Carbon, Hydrogen, Nitrogen, Phosphorus, Oxygen, and Sulfur (CHNOPS).
What are the most abundant elements in the universe?
Hydrogen, Helium, Oxygen, and Carbon.
Which element is a major element of life and part of CHNOPS?
Phosphorus.
Why is water essential for life?
Most biochemical reactions occur in water and biological molecules depend on its properties.
Why is water a polar molecule?
Oxygen is more electronegative than hydrogen, causing unequal electron sharing.
What type of bond forms between water molecules?
Hydrogen bonds.
What is cohesion?
Attraction of water molecules to each other.
What is adhesion?
Attraction of water molecules to other polar surfaces.
What property of water helps transport water through plant xylem?
Cohesion.
What is surface tension?
The strengthening of the water surface due to hydrogen bonding.
Why can some insects walk on water?
Surface tension.
Why is water called a universal solvent?
It dissolves more substances than any other liquid.
What kinds of substances does water commonly dissolve?
Salts, sugars, acids, alkalis, and gases.
What does hydrophobic mean?
Repelled by water or unable to mix with water.
Why is soap effective at removing oils?
Soap has hydrophobic and hydrophilic regions that emulsify fats.
What unusual property does water have when it freezes?
It expands and becomes less dense than liquid water.
Why does ice float?
Frozen water is less dense than liquid water.
What does amphoteric mean?
Able to act as both an acid and a base.
What is the equation for pH?
pH = -log10[H+].
What is neutral pH?
pH 7.
What pH is considered acidic?
Less than 7.
What pH is considered basic (alkaline)?
Greater than 7.
Why is blood pH tightly regulated?
Proper physiological function requires pH close to 7.
How does respiration help regulate blood pH?
CO₂ reacts with water to form carbonic acid and bicarbonate, creating a buffering system.
What is ketoacidosis?
Dangerous acidification of blood caused by ketone bodies.
Why can high blood lactate lower pH?
Lactate production releases H+ ions that increase acidity.
How does ocean acidification occur?
Atmospheric CO₂ dissolves in water and produces carbonic acid.
Why does ocean acidification threaten coral reefs?
It reduces carbonate ions needed to form calcium carbonate skeletons.
How is life currently classified?
Using nucleic acid comparisons such as rDNA sequences.
What are the three domains of life?
Bacteria, Archaea, and Eukaryotes.
What is binomial nomenclature?
The two-part scientific naming system using genus and species.
What is the scientific name of humans?
Homo sapiens.
What is a cell?
The smallest unit capable of performing all activities necessary for life.
Are all organisms made of cells?
Yes.
Can organisms be unicellular or multicellular?
Yes.
What are four major characteristics of living things?
Reproduction, growth and development, response to environment, and metabolism.
Why are viruses not considered living?
They cannot reproduce or carry out metabolism independently.
What is a prion?
An infectious misfolded protein.
Are prions considered living?
No.
What structures are found in all cells?
Plasma membrane, cytosol, nucleic acids, and ribosomes.
What is the plasma membrane?
A selective barrier separating the inside and outside of the cell.
What is cytosol?
The fluid interior of a cell.
What is cytoplasm?
Cytosol plus organelles, excluding the nucleus.
What are the two major cell types?
Prokaryotic and eukaryotic cells.
What is the main difference between prokaryotes and eukaryotes?
Eukaryotes have membrane-bound organelles; prokaryotes do not.
Which domains contain prokaryotes?
Bacteria and Archaea.
What groups belong to Eukaryotes?
Animals, plants, fungi, and protists.
What size are most bacterial cells?
Approximately 1-5 μm.
What size are most eukaryotic cells?
Approximately 10-100 μm.
What is a nucleoid?
Region where prokaryotic DNA is located.