The cell membrane is primarily composed of a phospholipid bilayer.
Missing Word
phospholipid
The phospholipid bilayer creates a selectively permeable barrier with hydrophilic heads facing outward and hydrophobic tails facing inward.
Category: Ch3
Question 2
The organelle known as the powerhouse of the cell is the mitochondria.
Missing Word
mitochondria
Mitochondria generate most of the cell's ATP through aerobic cellular respiration.
Category: Ch3
Question 3
The diffusion of water across a selectively permeable membrane is called osmosis.
Missing Word
osmosis
Water moves from areas of lower solute concentration to areas of higher solute concentration during osmosis.
Category: Ch3
Question 4
Proteins are synthesized at organelles called ribosomes.
Missing Word
ribosomes
Ribosomes can be free in the cytoplasm or bound to the rough endoplasmic reticulum.
Category: Ch3
Question 5
The rough endoplasmic reticulum is studded with ribosomes on its surface.
Missing Word
ribosomes
These ribosomes give the rough ER its characteristic appearance and synthesize proteins destined for secretion or membrane insertion.
Category: Ch3
Question 6
Digestive enzymes within the cell are contained in organelles called lysosomes.
Missing Word
lysosomes
Lysosomes break down worn-out organelles, food particles, and engulfed pathogens using hydrolytic enzymes.
Category: Ch3
Question 7
The Golgi apparatus packages proteins into vesicles for transport.
Missing Word
vesicles
The Golgi modifies, sorts, and packages proteins received from the rough ER for secretion or intracellular use.
Category: Ch3
Question 8
The process of cell division that produces two identical daughter cells is called mitosis.
Missing Word
mitosis
Mitosis ensures that each daughter cell receives an identical copy of the parent cell's DNA.
Category: Ch3
Question 9
DNA replication occurs during the S phase of the cell cycle.
Missing Word
S phase
The S phase (synthesis phase) is when the entire genome is duplicated in preparation for cell division.
Category: Ch3
Question 10
The movement of molecules from high to low concentration without energy is called diffusion.
Missing Word
diffusion
Diffusion is a passive process driven by the kinetic energy of molecules moving down their concentration gradient.
Category: Ch3
Question 11
A cell placed in a hypertonic solution will shrink due to water loss.
Missing Word
shrink
In a hypertonic solution, water moves out of the cell by osmosis because solute concentration is higher outside.
Category: Ch3
Question 12
The network of protein filaments that gives a cell its shape is the cytoskeleton.
Missing Word
cytoskeleton
The cytoskeleton consists of microfilaments, intermediate filaments, and microtubules that support cell structure and movement.
Category: Ch3
Question 13
Programmed cell death is known as apoptosis.
Missing Word
apoptosis
Apoptosis is a controlled process that eliminates damaged or unnecessary cells without causing inflammation.
Category: Ch3
Question 14
Transport that moves substances against their concentration gradient and requires ATP is called active transport.
Missing Word
active
Active transport uses carrier proteins and energy from ATP to move substances from low to high concentration.
Category: Ch3
Question 15
The region within the nucleus where ribosomal RNA is produced is the nucleolus.
Missing Word
nucleolus
The nucleolus assembles ribosomal subunits from rRNA and proteins before they are exported to the cytoplasm.
Category: Ch3