Chapter 3 Smartbook

In cell membranes, the phospholipids are arranged into a ______.

bilayer.

The ______ theory states that all life is composed of one or more cells, which are the fundamental units of all life.

cell

All living things consist of one or more ______.

cells.

Whether bacterium or blue whale, every organism is made of ______.

cells.

The organelle that is the site of photosynthesis in plant cells is the ______, which is a type of plastid.

chloroplasts

Short, numerous, hairlike structures that surround some cells like a fringe, are powered by microtubules, and have coordinated movements are called ______.

cilia.

Some protists, like Paramecium, are able to move through a watery environment with thousands of short extensions on the cell called ______.

cilia.

Select all of the following that describe microfilaments of the cytoskeleton.

composed of the protein actin, help anchor cells to each other, function in cell contraction and compression

The microfilaments, intermediate filaments, and microtubules shown in the picture comprise the ______ , which is a network of proteins that provide a structural framework within the cell.

cytoskeleton

The head of a phospholipid is ______, meaning its polar covalent bonds attract water, but the tails of a phospholipid are ______ and thus water-insoluble.

hydrophilic; hydrophobic

The ______ microscope is ideal for viewing living cells that are between 200 nanometers and 1 millimeter in size.

light

What organelle of the endomembrane system breaks down debris, food, and old cell parts with special dismantling enzymes?

lysosome

The ______ produced in the nucleus enters the cytoplasm and binds to ribosomes, the sites of protein synthesis.

mRNA

All cells have a cell ______ that surrounds the cytoplasm and forms a boundary between the cell and its environment.

membrane

Cellular respiration extracts energy from food and takes place in the organelle called a ______.

mitochondria.

The endomembrane system is a coordinated system of ______ in eukaryotic cells.

organelles

All cells are surrounded by cell membranes, also called plasma membranes, that separate the cytoplasm from the ______.

outside environment.

The cell membrane is composed of a type of lipid molecule called a(n) ______, which has two fatty acids and a phosphate group extending from a glycerol molecule.

phospholipid

Water, nutrients, hormones, and some organelles flow between adjacent plant cells through special channels in the cell wall called ______.

plasmodesmata.

Proteins to be secreted outside of a eukaryotic cell are formed at ribosomes on the surface of the ______ endoplasmic reticulum.

rough

Plant cells have large central ______ where water, salts, and sugars are stored and where materials are broken down and recycled with enzymes similar to lysosomes in animal cells.

vacuoles

Match each type of intercellular junction with its correct description. plasmodesmata - tight junctions - anchoring junctions - gap junctions -

- tunnels for the exchange of substances between adjacent plant cells - fuse cell membranes of adjacent animal cells, forming a barrier - connect animal cells to the extracellular matrix or to adjacent animal cells in one place - channels for the exchange of substances between adjacent animal cell

In eukaryotic cells, what is the function of chloroplasts?

Carry out photosynthesis.

What plant cell organelle can occupy up to 90% of the cell volume and can exert turgor pressure against the cell membrane when it acquires water?

Central vacuole.

What is the network of protein fibers and tubules inside the cell that provides support and aids in cell division and movement?

Cytoskeleton.

Select all of the following that are present in both prokaryotic cells and eukaryotic cells.

DNA, cytoplasm, ribosomes, and RNA.

In cell membranes, what part of a phospholipid molecule is oriented toward the outside of the bilayer?

Phosphate head.

Select all of the functions of the smooth endoplasmic reticulum.

Synthesize lipids and house enzymes that detoxify drugs and poisons.

Select all of the following that are present at the connection between normal cells of multicellular organisms.

Ways that cells can communicate with each other and a way for cells to adhere to one another.

Select all of the following that differ between domains Bacteria and Archaea.

Chemical composition of flagella, molecules that compose the cell membranes, and evolutionary relationship to eukaryotes.

What type of cell junction is shown in the picture?

Tight junction.

Select all the roles that membranes play in cells.

Transport substances into and out of the cell, enclose organelles in eukaryotic cells, and receive and respond to external stimuli.

______ cells are the simplest forms of life and lack a nucleus.

Prokaryotic

Select all of the following that are able to move laterally within the cell membrane, giving it the description of a fluid mosaic.

Proteins and phospholipids.

What cell structure binds to mRNA coming from the nucleus and manufactures proteins?

Ribosome.

Select all of the following that are able to pass freely through the phospholipid bilayer.

Small nonpolar molecules, O2 and CO2, and lipids.

What did Robert Hooke call the little units he observed when he viewed cork under lenses of glass?

The cell is the fundamental unit of all life. All cells originate from preexisting cells. All organisms are made of one or more cells.

In eukaryotic cells, the nucleus is an organelle that functions in ______.

housing the cell's DNA.

The endoplasmic ______ is a network of membranes originating at the nuclear envelope and winding through the cell.

reticulum

The nucleolus is a dense spot in the nucleus where components of ______ are assembled.

ribosomes

What is a network of sacs and tubules extending off the nuclear envelope and is where proteins and lipids are produced?

Endoplasmic reticulum.

Select all of the following that are present in bacterial cells.

Enzymes, DNA, ribosomes, and cytoplasm.

Key genetic sequences suggest that archaea are more closely related to members of domain ______ than they are to members of Domain Bacteria.

Eukarya

What type of microscope passes light through a transparent or thinly sliced specimen to generate true-color views of cells?

Light microscope.

Select all of the cell parts that are involved in the endomembrane system.

Nuclear envelope, gogli apparatus, vacuoles, lysosomes, and endoplasmic reticulum.

Select all of the characteristics of eukaryotic cells.

Nucleus, larger than prokaryotic cells, and system of internal membranes.

Review this chapter's Investigating Life essay. Magnetosomes are adaptive because they allow bacteria to save energy as they move toward an optimal ______.

O2 concentration.

Select all of the following that are true about prokaryotes.

Simplest types of life, lack a nucleus, and most ancient forms of life on Earth.

Organelles called lysosomes contain ______ that break down food particles, old organelles, and other cellular debris.

enzymes

The cell membrane can be described as a(n) ______ mosaic because many of the diverse components can move freely within the cell membrane.

fluid

What English physicist first observed the outlines of cells when he looked at cork from an oak tree?

Hooke.

What molecules are key components of cell membranes and are arranged in bilayers to form membranes?

Phospholipids.