Biology CHAPTER 4

Cell Homeostasis

Cell Homeostasis

The role of the cell membrane is most like the job of which person?

a police officer who allows select people to enter and leave a crime scene

Which organisms are prokaryotes?

archaea

Reptiles and birds excrete waste as an insoluble white solid that is called uric acid. How does this help them to maintain internal homeostasis in hot climates?

by retaining water

Consider this animal cell. mc004-1.jpg Which organelle is labeled H?

cell membrane

Which best defines homeostasis?

maintaining a stable internal environment

A chemical has been found to harm the same components in both prokaryotic and eukaryotic cells. Which components are those?

DNA, cell membrane, cytoplasm, and ribosomes

Consider this animal cell. mc005-1.jpg Which organelle is labeled A?

Golgi apparatus

Consider this plant cell. mc002-1.jpg Which organelle is labeled E?

Golgi apparatus

If the endoplasmic reticulum were removed from the cell, which organelle would not be able to function properly to receive, package, and distribute proteins?

Golgi apparatus

What was Rudolph Virchow's contribution to the cell theory?

He concluded that all cells come from preexisting cells.

What would most likely happen to a unicellular organism if it was exposed to a hypotonic solution for an extended period of time?

It would swell and then burst.

A scientist discovers a cell that has chloroplasts, cytoplasm, DNA, and a cell membrane. Which statement best describes how the cell could be classified?

The cell is eukaryotic because it has chloroplasts.

A scientist is studying a cell and can clearly see that it has ribosomes and mitochondria. Which statement best describes how the cell could be classified?

The cell is eukaryotic because it contains mitochondria.

Which reason best explains why the cell membrane helps the cell maintain homeostasis?

The cell membrane is selectively permeable.

How does the cell wall protect a plant cell?

The cell wall is thick and fibrous and provides a barrier between the cell and its external environment.

What would most likely happen to a plant cell if its chloroplasts were removed?

The cell would die because it could not make food.

A student wonders whether removing the nucleus from a cell would result in a new prokaryotic cell. Why would this procedure fail to produce a prokaryotic cell?

The cell would lack genetic information.

The data in the graph are the result of a paramecium being placed in a hypertonic salt solution. mc026-1.jpg Based on the data in the graph, which would most likely happen if the paramecium were placed in distilled water?

The contractions would increase.

The nucleolus✔ of the cell directs cell activity and acts like the control center.

The nucleolus✔ of the cell directs cell activity and acts like the control center.

Which is a tough and flexible layer that surrounds plant cells, as well as some algal and bacterial cells?

cell wall

Which organelles are found only in plant cells?

cell wall, chloroplasts

Consider this animal cell. mc001-1.jpg Which organelles are labeled D?

centrioles

Consider this animal cell. mc007-1.jpg Which organelles are labeled D?

centrioles

A student constructs a Venn diagram to compare the organelles in plant and animal cells. Venn Diagram of Plant and Animal Cells mc024-1.jpg Which organelle should be listed under Plant Only in the diagram?

chloroplast

Which microscope did Robert Hooke use to study tree bark?

compound light microscope

Consider the cell structure that is shown below. mc015-1.jpg Which is a function of the structure that is represented in the image?

controls the movement of substances into and out of cells

In which specimen were cells first identified?

cork bark

Which cell structure serves the stated function in both eukaryotic and prokaryotic cells?

cytoplasm: protects cell structures

What is the maximum magnification of a compound light microscope?

2,500x

For diffusion to occur, which condition must be met?

A concentration gradient must exist.

Which is a component of the modern cell theory that was not part of the original cell theory?

All cells are similar in composition and metabolic activities.

Animal and Plant Cells

Animal and Plant Cells

In the 1600s, which scientist discovered microbes in pond water by using a microscope?

Anton van Leeuwenhoek

Which statement is most likely to apply to a cell that has DNA within its cytoplasm?

It performs all functions for the organism.

Which statement about the cell wall is true?

It prevents a plant cell from bursting.

Which statement about cell membranes is true?

The cell membrane is enclosed by the cell wall in a plant cell.

What is unique about the cell wall compared to the cell membrane?

The cell wall has cellulose.

A magnifying glass is an example of which type of microscope?

simple microscope

Which discovery supported the endosymbiotic theory?

DNA in mitochondria

Which is a major difference between the cell membrane and the cell wall?

Cell membranes are found in animal and plant cells; cell walls are found only in plant cells.

The endosymbiotic theory provides an explanation for the origin of chloroplasts. Which trait of chloroplasts supports this explanation?

Chloroplasts have their own DNA.

Which best describes mitochondrial DNA (mtDNA)?

Mitochondrial DNA can be traced for generations.

The data in the graph are the result of a paramecium being placed in a hypertonic salt solution. mc025-1.jpg What change would most improve the usefulness of the graph?

Replace the concentration descriptions with actual values.

Who first recognized the cell as the universal unit of life?

Schleiden and Schwann

Which reason best explains why dead specimens must be used with transmission electron microscopes?

Specimens are placed in a vacuum.

What function do chloroplasts perform?

They use light energy to make food for the plant.

Based on the endosymbiotic theory, what cell would result from the endosymbiosis of a cell with a cyanobacterium?

a eukaryotic cell that can make its own food

Chlorophyll is found in plant leaves and absorbs light from the sun to enable plants to perform photosynthesis. Magnesium is an important component of chlorophyll. The concentration of magnesium ions is higher in the root-hair cells of plants than in the soil. Which mechanism of ion uptake would best enable a plant to produce a steady supply of chlorophyll?

active transport

Which homeostatic process moves particles against a concentration gradient?

active transport

Which homeostatic process requires energy to move particles across the plasma membrane?

active transport

Which movement of particles would be most affected by a disorder that causes damage to carrier proteins?

active transport

According to the cell theory, which structure contains cells?

blood

Which adaptation is used by polar bears to maintain internal homeostasis in cold temperatures?

blubber

Which organelle can be compared to a security guard who decides whom may enter a building and whom may not?

cell membrane

The first strands of DNA were observed through which microscope?

electron microscope

Which is an extensive network of tubes, sacs, and vesicles throughout the cell that provides transport as its main function?

endoplasmic reticulum

What is shown in the image? mc010-1.jpg

eukaryote

Which motion of particles across a membrane requires energy?

from low concentration to high concentration

Which is a characteristic of the cell membrane?

has a phospholipid bilayer

A patient is in need of hydration. Which type of solution are the patient's cells most likely in?

hypertonic

Which term refers to a solution with more molecules outside the cell than inside the cell?

hypertonic

Which solution would most likely cause a plant placed in it to become firmer and more rigid?

hypotonic

Which was Ventor's contribution to science?

invented a synthetic cell

Which organelle contains digestive enzymes that break down waste material and debris in the cell?

lysosome

Which organelle is most likely to be missing from the cells of a leaf?

lysosome

An animal cell (left) and a plant cell (right) are shown. mc010-1.jpg Which two cell parts are most likely found in both types of cell?

lysosome and vacuole

The endosymbiotic theory helps to explain the origin of which structures?

mitochondria

Consider this animal cell. mc008-1.jpg Which organelle is labeled I?

nucleus

The table lists some organelles and functions. Only one pair is correctly matched. Functions of Organelles Organelle Function Nucleus Directs cell activity Endoplasmic reticulum Breaks down sugar molecules to supply energy Golgi apparatus Supports and protects organelles in the cell Lysosome Produces proteins for the cell Which organelle in the table is correctly matched with its function

nucleus

Which is a structure that contains the cell's hereditary information and controls the cell's growth and reproduction?

nucleus

Which was the first cell viewed by the light microscope?

oak bark

Consider this animal cell. mc006-1.jpg Which organelle is responsible for producing the energy for cellular processes?

organelle G

Water makes up a large percentage of the body's cells. For a cell to remain in homeostasis, there must be a mechanism to control water changes in the cells. The movement of water from an area of high water concentration to an area of low water concentration is

osmosis

Which homeostatic process is characterized by the diffusion of water molecules?

osmosis

What is shown in the image? mc009-1.jpg

prokaryote

Consider the plant cells in the image below. mc019-1.jpg Which is a function of the cell structure that is labeled X?

provides support

A diseased cell is no longer able to produce proteins. Which cell structure is most likely malfunctioning?

ribosome

The table lists some organelles and functions. Only one pair is correctly matched. Functions of Organelles Organelle Function Lysosome Stores water and waste materials Vacuole Breaks down sugars Mitochondrion Breaks down waste materials and debris Ribosome Produces proteins for the cell Which organelle in the table is correctly matched with its function?

ribosome

Through which microscope were cells first observed?

simple microscope

The discovery of mitochondrial DNA (mtDNA) had no effect on which area of scientific investigation?

study of cork bark

Consider this animal cell. mc016-1.jpg What is the function of the organelles that are labeled F?

to move proteins and other substances through the cell

A new multicellular organism has been discovered, and scientists want to study the organism's cell structures, including organelles. Which microscope should they use?

transmission electron microscope

Consider this plant cell. mc006-1.jpg Which organelle is labeled A?

vacuole

Herbicides are being used to kill weeds in a nearby field. The plants absorb the herbicides from the soil. Which organelle in the plant will most likely store the absorbed herbicide waste?

vacuole

Which organelle is used as temporary storage for water, waste products, food, and other cellular material?

vacuole

How would the contractile vacuole of a freshwater amoeba respond if the organism was placed in seawater?

with fewer contractions