Cells

Lysosomes are organelles that contain enzymes. Which of the following is a function of lysosomes?

Lysosomes break down lipids, carbohydrates, and proteins.

The cell membrane consists of a lipid bilayer with embedded proteins. What is one reason that proteins are essential for the cell membrane to function properly?

Proteins allow certain substances to pass through the cell membrane.

The illustration shows a model of the transport of solute particles from outside the cell to inside the cell. What type of cell transport is modeled?

The model illustrates active transport because energy is required for solute particles to cross the cell membrane.

Which structure is common to all three types of cells?

a cell membrane that surrounds the cell

The cells of all organisms contain DNA. In cells of which of the following groups is the cellular DNA enclosed in a nucleus?

eukaryotes

A student is developing a model to show how proteins are synthesized in animal cells. Which organelles should the student include in the model? Select all that apply.

ribosomes

passive transport

-does not use cellular energy -Particles move from an area of high concentration to an area of low concentration

Elizabeth is conducting an investigation to study how molecules are transported into and out of a cell. Elizabeth builds a model of a cell using a U-shaped tube. A barrier, which is permeable to water, but not sugar, is placed on the bottom of the tube to model the cell membrane. Elizabeth adds two different solutions to each side of the tube. The solute in each solution is sugar and the solvent is water. The initial levels of solution in Side A and Side B are equal. The concentration of sugar in Side A is lower than the concentration of sugar in Side B. What is Elizabeth likely to observe?

Water molecules will move from Side A to Side B. The solution level on Side A will fall and the solution level on Side B will rise.

A cell is placed in an isotonic solution. How does the cell maintain homeostasis in this environment?

Water will move across the cell membrane in both directions because the concentrations of solute particles inside and outside the cell are the same.

The diagram is a model of the structure of a certain type of cell. Like all models, the diagram is accurate in many ways, but it does not show all features or properties. For example, the structure labeled 2 may take on a variety of sizes, depending on the amount of water available to the cell. The structure labeled 4 occurs in different numbers in different examples of the cell. It has a characteristic green color and is involved in energy transformation. What type of cell is shown by the diagram?

a plant cell, as shown by the presence of the nucleus, cell wall, and chloroplasts

Many scientists depend on electron microscopes to study cells and cell structures. Which of the following is an advantage of electron microscopes over light microscopes?

Electron microscopes produce highly magnified images.

A number of scientists made contributions to cell theory. Which scientist was the first to use a light microscope to observe cells in a slice of cork?

Robert Hooke

Which organelles allow plants to support heavy structures such as leaves and flowers?

the vacuoles because they are filled with fluid, which provide rigidity

active transport

-requires cellular energy -Particles move from an area of low concentration to an area of high concentration -includes endocytosis and exocytosis

Which of the following statements is part of the cell theory? A. Cells are composed mostly of empty space. B. Cells are generally large enough for the unaided eye to see. C. All cells are produced from existing cells. D. Only animals are made up of cells.

All cells are produced from existing cells.

A scientist is studying a cell from an unidentified organism. Which feature of the cell provides the strongest evidence that the organism is a prokaryote, and not a eukaryote?

The cell lacks a nucleus and other membrane-bound organelles.

Lionel places red blood cells in a beaker of pure water and then observes their activity under a microscope. Which of the following is the most likely result that Lionel will obtain?

Water diffuses into the red blood cells by osmosis, and the cells eventually burst.

Nicole is studying plant cells under a microscope. She observes one set of structures that she identifies as chloroplasts, and she observes another set of structures that she identifies as mitochondria. Is it possible that Nicole has correctly identified these structures?

Yes. Many plant cells have both mitochondria and chloroplasts.

A membrane separates a concentrated glucose solution from a dilute glucose solution. The membrane is permeable to water, but not glucose. Will the water move across the membrane by osmosis?

Yes. Water moves from the dilute solution to the concentrated solution.

Order the tiles so that they are arranged from the simplest level on the left to the most complex level on the right. organ, tissue, cell, organ system

ceel, tissue, organ, organ system

What structures surround and protect the cell?

cell membrane surrounded by a cell wall

Which of the following structures are typically present in both plant and animal cells?

mitochondria

The human digestive system is comprised of specialized cells, tissues, and organs. Order the images so that they are arranged from the least complex level on top to the most complex level on the bottom. smooth muscle tissue, stomach, muscle cell, digestive system

muscle cell, smooth muscle tissue, stomach, digestive system

Microscopes can be used to explore cells. Which of the following types of microscopes is used to produce a three-dimensional image of the surface of a cell?

scanning electron microscope

A scientist is comparing ribosomes in a prokaryotic cell and a eukaryotic cell. Which of the following is a property of the ribosomes in the eukaryotic cell only and not the prokaryotic cell?

Some of the ribosomes are located in the endoplasmic reticulum.

All cells contain cell membranes. Which of the following describes the composition of cell membranes?

Cell membranes are composed of lipid molecules, which provide a flexible structure.

Which statement best explains why cell theory is classified as a theory, and not a hypothesis?

Cell theory is supported by evidence from a wide range of investigations that together tested many related hypotheses.

The model shows a substance crossing a cell membrane. Which of the following describes the process? A. The model shows the process of active transport because the solute particles are moving from an area of low concentration to an area of high concentration. B. The model shows the process of bulk transport because the solute particles are moving from an area of low concentration to an area of high concentration. C. The model shows the process of diffusion because solute particles are moving from an area of high concentration to an area of low concentration. D. The model shows the process of osmosis because the solute particles are moving from an area of high concentration to an area of low concentration.

The model shows the process of active transport because the solute particles are moving from an area of low concentration to an area of high concentration.

The model illustrates a process by which a substance is taken up by a cell. Which statements describe the process?

The model shows the process of endocytosis.

Multicellular organisms contain organ systems. Which of the following BEST describes the organs in an organ system?

The organs in an organ system work together to perform a specific function.

The movement of matter across a cell membrane against a concentration difference is called~~~~ , and it requires~~~~

active transport, energy

The cell membrane is described as highly selective. It bars the passage of most but not all substances. What structural feature of the cell membrane acts like gates that allow certain substances, including water, to pass through?

channels in transmembrane proteins embedded in the lipid bilayer

A model of a plant cell is shown. Which of the structures are present in plant cells, but not in animal cells? Select all that apply. nucleus, chloroplast, golgi apparatus, cell wall

chloroplast, cell wall