CELL THEORY AND CELL ORGANELLES
Which scientist first observed and named "cells" after viewing cork under a microscope?
A. Antonie van Leeuwenhoek
B. Robert Hooke
C. Matthias Schleiden
D. Rudolf Virchow
B. Robert Hooke
Which tissue covers body surfaces and lines internal organs?
A. Connective Tissue
B. Muscular Tissue
C. Epithelial Tissue
D. Nervous Tissue
C. Epithelial Tissue
During which phase of the cell cycle does DNA replication occur?
A. G1 Phase
B. G2 Phase
C. S Phase
D. M Phase
C. S Phase
hich transport mechanism moves molecules from an area of higher concentration to lower concentration without using energy?
A. Active Transport
B. Diffusion
C. Endocytosis
D. Exocytosis
B. Diffusion
Which organelle is known as the "powerhouse of the cell" because it produces ATP?
A. Ribosome
B. Golgi Apparatus
C. Mitochondrion
D. Lysosome
C. Mitochondrion
Which statement is NOT part of the modern Cell Theory?
A. Cells are the basic unit of life.
B. All living organisms are made of cells.
C. Cells arise from pre-existing cells.
D. Cells can develop spontaneously from nonliving matter.
D. Cells can develop spontaneously from nonliving matter.
Which tissue is responsible for transmitting electrical impulses throughout the body?
A. Nervous Tissue
B. Muscular Tissue
C. Connective Tissue
D. Epithelial Tissue
A. Nervous Tissue
Which stage of mitosis is characterized by chromosomes lining up at the cell's equator?
A. Prophase
B. Metaphase
C. Anaphase
D. Telophase
B. Metaphase
A white blood cell engulfs a bacterium. Which transport mechanism is being demonstrated?
A. Exocytosis
B. Facilitated Diffusion
C. Endocytosis
D. Osmosis
C. Endocytosis
A red blood cell is placed in a hypertonic solution. What will most likely happen?
A. It will swell and burst.
B. It will remain unchanged.
C. It will lose water and shrink.
D. It will divide rapidly.
C. It will lose water and shrink.
A biotechnology company is developing cells that can produce large amounts of insulin for diabetic patients. During observation, scientists notice that these cells contain an unusually high number of ribosomes attached to the endoplasmic reticulum. Why is this adaptation beneficial to the cell?
A. It increases lipid production for membrane repair.
B. It allows rapid synthesis of proteins that will be secreted.
C. It stores more genetic information.
D. It produces additional ATP for cell division.
B. It allows rapid synthesis of proteins that will be secreted.
A mountain climber suffers severe burns that destroy the outer layer of the skin. Within days, doctors become concerned about infection and dehydration. Which explanation best describes why these complications occur?
A. The damaged tissue can no longer transmit nerve impulses.
B. The protective barrier formed by epithelial tissue has been lost.
C. The connective tissue can no longer contract.
D. Muscle cells can no longer generate energy.
B. The protective barrier formed by epithelial tissue has been lost.
Researchers test a chemical that prevents spindle fibers from attaching to chromosomes during mitosis. After treatment, many cells contain abnormal numbers of chromosomes. Which event most likely caused this result?
A. DNA was replicated twice.
B. Protein synthesis completely stopped.
C. Cytokinesis occurred before mitosis.
D. Chromosomes failed to separate correctly during cell division.
D. Chromosomes failed to separate correctly during cell division.
A laboratory technician accidentally places healthy plant cells into a highly concentrated salt solution. After several minutes, the cells appear shrunken. Which process best explains this observation?
A. Water entered the cells through osmosis, causing turgor pressure.
B. Water left the cells through osmosis, causing plasmolysis.
C. Glucose entered through facilitated diffusion.
D. ATP was used to pump water out of the cells.
B. Water left the cells through osmosis, causing plasmolysis.
A patient accidentally touches a hot pan. Within seconds, they quickly pull their hand away before consciously realizing the pain. Which tissues worked together to produce this response?
A. Epithelial and connective tissues
B. Connective and muscular tissues
C. Nervous and muscular tissues
D. Epithelial and nervous tissues
C. Nervous and muscular tissues
A patient's cells continue producing proteins, but laboratory tests show that these proteins never reach their intended destinations inside or outside the cell. Which cellular structure is most likely responsible for this problem?
A. Lysosome
B. Nucleolus
C. Mitochondrion
D. Golgi Apparatus
D. Golgi Apparatus
Following a serious accident, a patient is able to think clearly but cannot voluntarily move their arms and legs. Medical imaging shows that the muscles are healthy. Which tissue is most likely affected?
A. Connective Tissue
B. Epithelial Tissue
C. Nervous Tissue
D. Cardiac Muscle Tissue
C. Nervous Tissue
During a medical examination, doctors discover that certain cells continue dividing even after severe DNA damage is detected. Which failure within the cell cycle most likely allowed this to happen?
A. The cell membrane became more permeable.
B. The G1 checkpoint failed to stop damaged cells.
C. Ribosomes stopped producing proteins.
D. Mitochondria produced excess ATP.
B. The G1 checkpoint failed to stop damaged cells.
Scientists genetically modify cells so that all membrane transport proteins become nonfunctional, while the membrane itself remains intact. Which substance would have the greatest difficulty entering the cell?
A. Oxygen
B. Carbon dioxide
C. Glucose
D. Lipid molecules
C. Glucose
Scientists discover a mutation that prevents damaged cells from stopping at the G1 checkpoint. Over time, these abnormal cells continue to divide and spread throughout the body. Which conclusion is best supported by this observation?
A. The mutation increases the rate of protein synthesis.
B. The mutation may lead to cancer.
C. The mutation causes cells to lose their mitochondria.
D. The mutation prevents osmosis from occurring.
B. The mutation may lead to cancer.
Scientists successfully disable the mitochondria of a living cell while leaving all other organelles intact. After several hours, the cell begins to fail even though its DNA remains undamaged. Which explanation best accounts for this observation?
A. The cell cannot generate enough ATP to support essential activities.
B. The cell loses its ability to package proteins.
C. Ribosomes immediately stop producing proteins.
D. The nucleus can no longer store genetic material.
A. The cell cannot generate enough ATP to support essential activities.
An athlete tears a tendon during a competition. Although the muscles remain strong, movement becomes difficult and painful. Which conclusion best explains this condition?
A. The connective tissue linking muscles to bones has been damaged.
B. The muscles cannot receive oxygen.
C. The epithelial tissue can no longer protect the muscles.
D. The nervous tissue has completely stopped functioning.
A. The connective tissue linking muscles to bones has been damaged.
A pharmaceutical company develops a drug that blocks cyclin activity in rapidly dividing cells. Before human testing, scientists predict which tissues will be affected first. Which prediction is most reasonable?
A. Skin tissue will be affected because its cells divide frequently.
B. Mature neurons will divide more slowly.
C. Skeletal muscles will immediately stop contracting.
D. Red blood cells will begin mitosis
A. Skin tissue will be affected because its cells divide frequently.
A mutation prevents secretory vesicles from merging with the plasma membrane. Although proteins are produced normally, they remain trapped inside the cell. Which cellular process has most likely been disrupted?
A. Diffusion
B. Facilitated Diffusion
C. Endocytosis
D. Exocytosis
D. Exocytosis
Two organisms produce gametes through meiosis. Organism A experiences normal crossing over, while Organism B has a mutation that completely prevents crossing over during Prophase I. Both organisms still complete meiosis successfully.
Which conclusion is most reasonable?
A. Organism B will produce more gametes than Organism A.
B. Organism B will be unable to complete meiosis.
C. Organism B will produce diploid gametes instead of haploid gametes.
D. Organism B will produce genetically less diverse gametes than Organism A.
D. Organism B will produce genetically less diverse gametes than Organism A.