Chapter 1
What makes a scientific theory stronger than a hypothesis?
It's supported by repeated experiments and broad evidence.
Which particle has a negative charge and very little mass?
Electron.
What is the difference between a monomer and a polymer?
Monomers are small, repeating subunits; polymers are long chains made by linking those monomers
Which organelle is responsible for producing ribosomal RNA (rRNA)?
Nucleolous.
Which part of a cell provides structure and protection in plants, fungi, and many bacteria?
Cell Wall
Which of the following best describes a hypothesis?
A) A guess with no testing
B) A testable statement
C) A fact proven true
D) An opinion
B) A testable statement
Atoms with the same protons but different neutrons are called ____ .
Isotopes.
Which reaction links monomers together to form polymers? Draw an illustration.
A) Hydrolysis
B) Dehydration synthesis
C) Oxidation
D) Denaturation
B – Dehydration synthesis.
Which of the following organelles is found in plant cells but not in animal cells?
A) Mitochondria
B) Chloroplasts
C) Nucleus
D) Endoplasmic reticulum
E) Ribosomes
B) Chloroplasts
Which structure in cells does not have a surrounding membrane?
A) Endoplasmic reticulum
B) Lysosome
C) Nucleoid
D) Golgi apparatus
C) Nucleoid
Give one example of deductive reasoning in biology
If all plants need sunlight, then a new plant species will also require sunlight
If all mammals produce milk, then a newly discovered mammal will also produce milk
The atomic number tells you how many ___ an atom has.
Protons.
Name the four major classes of macromolecules found in living organisms.
Carbohydrates, proteins, nucleic acids, lipids.
Which organelle is the first stop for a protein destined for secretion?
Endoplasmic reticulum (ER). (I'll even take endomembrane system, although this response is a lot broader)
Which of the following correctly distinguishes DNA from RNA?
A) DNA contains uracil, while RNA contains thymine
B) DNA is usually double-stranded, while RNA is usually single-stranded
C) DNA uses ribose sugar, while RNA uses deoxyribose
D) DNA is found only in the cytoplasm, while RNA is found only in the nucleus
B) DNA is usually double-stranded, while RNA is usually single-stranded
How do beak shapes illustrate natural selection? (IMG-1)
Beak shapes are adaptations to specific food sources (seed eater, cactus eater, insect eater), and traits that improve survival are passed on to future generations.
What are these? (IMG-2)
Isotopes
Identify which is nonpolar, which is polar, and which is charged. (IMG-3)
Nonpolar → hydrophobic side chain
Polar → hydrophilic, uncharged side chain
Charged → carries positive or negative charge in solution
What theory does this image illustrate, and which two organelles are explained by it? (IMG-4)
Endosymbiosis; mitochondria and chloroplasts.
Identify one structure present in all three, and one structure unique to only one of them. (IMG-6)
All three: Ribosomes or plasma membrane
Unique: Chloroplasts in plants, nucleoid in bacteria, lysosomes in animals
Why is it important that scientific theories can change over time, and how does this relate to the role of hypotheses and evidence?
Theories can change because new evidence may support, refine, or challenge what we thought we knew.
Hypotheses are the smaller, testable pieces that add up to this evidence.
Being open to change makes science reliable because it adapts and improves as knowledge grows.
Fill in the Blanks:
In ______ bonds, atoms share electrons; strongest and forms stable molecules.
In ______ bonds, an atom donates an electron creating oppositely charged ions that attract.
In ______ bonds, a weak attraction between a ______ with partial postive charge and an atom like oxygen or nitrogen with a partial negative charge.
Covalent; Ionic; Hydrogen (2)
Mix and Match: Types of RNA and Their Roles
Instructions: Match each RNA type in the bank with its correct role in protein synthesis.
RNA Bank:
Messenger RNA (mRNA)
Ribosomal RNA (rRNA)
Transfer RNA (tRNA)
Roles/Functions (Scrambled):
A) Brings amino acids to the ribosome during protein synthesis
B) Carries genetic information from DNA
C) Makes up part of the ribosome
1 → B
2 → C
3 → A
Label the pathway shown in the image and explain its importance. (IMG-5)
Ribosome → ER → Golgi → Vesicle → Plasma membrane; ensures proteins are correctly processed and delivered.
Compare eukaryotic and prokaryotic cells in terms of internal membranes. How does this difference affect the complexity of their functions?
Prokaryotes: Lack internal membranes, so processes occur in the cytoplasm.
Eukaryotes: Have membrane-bound organelles (nucleus, ER, Golgi, mitochondria, etc.) that compartmentalize tasks, allowing specialization and more complex regulation.