Question 1

What is (unified) cell theory?

Accepted Answer

A biological concept that states that all organisms are composed of one or more cells; the cell is the basic unit of life; and new cells arise from existing cells.

Question 2

What is a microscope?

Accepted Answer

An instrument that magnifies an object.

Question 3

What is an electron microscope?

Accepted Answer

An instrument that magnifies an object using a beam of electrons passed and bent through a lens system to visualize a specimen.

Question 4

What is a light microscope?

Accepted Answer

An instrument that magnifies an object using a beam of visible light passed and bent through a lens system to visualize a specimen.

Question 5

What is a cell?

Accepted Answer

A cell is the smallest unit of a living thing (an organism), which can be made of one cell or many cells. Cells are the basic building blocks of all organisms.

Question 6

What are the levels of organization of an organism?

Accepted Answer

Cells of one kind that interconnect with each other and perform a shared function form tissues, tissues combine to form an organ, organs combine to form an organ system, and organ systems together form an organism.

Question 7

What are the broad categories of cells?

Accepted Answer

Prokaryotic and eukaryotic.

Question 8

What are some examples of prokaryotic and eukaryotic cells?

Accepted Answer

Animal and plant cells are eukaryotic and bacterial cells are prokaryotic.

Question 9

What are micrographs?

Accepted Answer

Photographs of cells taken with a microscope.

Question 10

How does a microscope lens change the orientation of an image?

Accepted Answer

A specimen that is right-side up and facing right on the microscope slide will appear upside-down and facing left when view through a microscope. If the slide is moved left, it will appear to move right, and if moved down will appear to move up.

Question 11

Why are microscope images inverted?

Accepted Answer

Because microscopes use two sets of lenses to magnify the image. Because of the manner in which light travels through the lenses, this system of two lenses produces an inverted image.

Question 12

What are binocular or dissecting microscopes?

Accepted Answer

These microscopes include an additional magnification system that makes the final image appear upright.

Question 13

How large are typical human red blood cells?

Accepted Answer

They are about eight millionths of a meter or eight micrometers (8 μm) in diameter. About 250 red blood cells could fit on the head of a pin, which is about two thousandths of a meter (2 mm).

Question 14

What are the downsides of viewing cells with light microscopes?

Accepted Answer

Individual cells are generally transparent, and their components are not distinguishable unless they are colored with special stains, which usually kills the cells.

Question 15

Which parameters are important in microscopy?

Accepted Answer

Magnification and resolving power.

Question 16

What is magnification?

Accepted Answer

Magnification is the process of enlarging an object in appearance.

Question 17

What is resolving power?

Accepted Answer

Resolving power is the ability of a microscope to distinguish two adjacent structures as separate: the higher the resolution, the better the clarity and detail of the image.

Question 18

What do oil immersion lenses do?

Accepted Answer

They can usually increase magnification up to 1000 times.

Question 19

Which category of microscope is used to study cellular structure and function?

Accepted Answer

Electron microscopes.

Question 20

What is the magnification and resolution of a typical light microscope used in a college biology lab?

Accepted Answer

The magnification is approximately 400 times with a resolution of about 200 nanometers.

Question 21

What is the magnification and resolution of a typical electron microscope?

Accepted Answer

The magnification is approximately 100,000 times with a resolution of about 50 picometers.

Question 22

What is the impact of electron microscopy on a specimen?

Accepted Answer

The method used to prepare the specimen for viewing with an electron microscope kills the organism. Electrons have short wavelengths (shorter than photons) that move best in a vacuum, so living cells cannot be viewed with an electron microscope.

Question 23

How do scanning electron microscopes work?

Accepted Answer

A beam of electrons moves back and forth across a cell's surface, creating details of cell surface characteristics.

Question 24

How do transmission electron microscopes work?

Accepted Answer

An electron beam penetrates the cell and provides details of a cell's internal structures.

Question 25

Who was Antony van Leeuwenhoek?

Accepted Answer

A Dutch shopkeeper with great skill in crafting lenses in the 1600s and who was able to observe the movements of protists and sperm, which he collectively termed “animalcules”.

Question 26

When was the term “cell” first used in publication?

Accepted Answer

In a 1665 publication called Micrographia , experimental scientist Robert Hooke coined the term “cell” for the box-like structures he observed when viewing cork tissue through a lens.

Question 27

When were bacteria and protozoa discovered?

Accepted Answer

In the 1670s by Antony van Leeuwenhoek.

Question 28

When was the unified cell theory proposed?

Accepted Answer

In the late 1830s, botanist Matthias Schleiden and zoologist Theodor Schwann were studying tissues and proposed the unified cell theory. Rudolf Virchow later made important contributions to the theory.

Question 29

What is a pap smear?

Accepted Answer

A test in which a doctor takes a small sample of cells from the uterine cervix of a patient and sends it to a medical lab where a cytotechnologist stains the cells and examines them for any changes that could indicate cervical cancer or a microbial infection.

Question 30

What do cytotechnologists do?

Accepted Answer

Cytotechnologists are professionals who study cells via microscopic examinations and other laboratory tests. They are trained to determine which cellular changes are within normal limits and which are abnormal. They study cellular specimens that come from all organs. When they notice abnormalities, they consult a pathologist, who is a medical doctor who can make a clinical diagnosis.

Question 31

What is a nucleoid?

Accepted Answer

The central part of a prokaryotic cell in which the chromosome is found.

Question 32

What is a prokaryote?

Accepted Answer

A unicellular organism that lacks a nucleus or any other membrane-bound organelle.

Question 33

What are the common components of all cells?

Accepted Answer

1. Plasma membrane 2. Cytoplasm 3. DNA 4. Ribosomes

Question 34

What is the purpose of a prokaryotic cell wall?

Accepted Answer

Most prokaryotes have a peptidoglycan cell wall that acts as an extra layer of protection, helps the cell maintain its shape, and prevents dehydration.

Question 35

What is the purpose of a prokaryotic capsule?

Accepted Answer

Most prokaryotes have a polysaccharide capsule that enables the cell to attach to surfaces in its environment.

Question 36

What is the purpose of prokaryotic flagella?

Accepted Answer

Some prokaryotes have flagella which are used for locomotion.

Question 37

What is the purpose of pili?

Accepted Answer

Some prokaryotes have pili which are used to exchange genetic material during a type of reproduction called conjugation.

Question 38

What is the purpose of fimbriae?

Accepted Answer

Some prokaryotes have fimbriae that are used by bacteria to attach to a host cell.

Question 39

What are some examples of beneficial microbes?

Accepted Answer

Microbes in the gut that make vitamin K and those that ferment beer and wine.

Question 40

What are some industries in which microbiologists work?

Accepted Answer

The food industry, veterinary and medical fields, and in the pharmaceutical sector, serving key roles in research and development by identifying new sources of antibiotics that could be used to treat bacterial infections.

Question 41

How do microbiologists work in bioremediation?

Accepted Answer

Environmental microbiologists may look for new ways to use specially selected or genetically engineered microbes for the removal of pollutants from soil or groundwater, as well as hazardous elements from contaminated sites.

Question 42

How do microbiologists work in bioinformatics?

Accepted Answer

They provide specialized knowledge and insight for the design, development, and specificity of computer models, for example of bacterial epidemics.

Question 43

How large are cells?

Accepted Answer

Prokaryotic cells are on average between 0.1 and 5.0 μm in diameter, while eukaryotic cells have diameters ranging from 10 to 100 μm.

Question 44

What are some benefits of the small size of prokaryotes?

Accepted Answer

The small size of prokaryotes allows quick entry and diffusion of ions and molecules to other parts of the cell while also allowing fast removal of waste products out of the cell.

Question 45

Why is the size of cells limited?

Accepted Answer

The formula for the surface area of a sphere is 4π2, while the formula for its volume is 4π2/3. Thus, as the radius of a cell increases, its surface area increases as the square of its radius, but its volume increases as the cube of its radius (much more rapidly). Therefore, as a cell increases in size, its surface area-to-volume ratio decreases. If the cell grows too large, the plasma membrane will not have sufficient surface area to support the rate of diffusion required for the increased volume. In other words, as a cell grows, it becomes less efficient.

Question 46

What are some ways in which cells can become more efficient when growing in size?

Accepted Answer

Cell division, or the evolutionary development of organelles to perform specific tasks.

Question 47

What is a cell wall?

Accepted Answer

A rigid cell covering that protects the cell, provides structural support, and gives shape to the cell.

Question 48

What is a central vacuole?

Accepted Answer

A large plant cell organelle that regulates the cell's storage compartment, holds water, and plays a significant role in cell growth as the site of macromolecule degradation.

Question 49

What is a centrosome?

Accepted Answer

A region in animal cells made of two centrioles.

Question 50

What is chlorophyll?

Accepted Answer

A green pigment that captures the light energy that drives the light reactions of photosynthesis.

Question 51

What is a chloroplast?

Accepted Answer

A plant cell organelle that carries out photosynthesis.

Question 52

What is chromatin?

Accepted Answer

A protein-DNA complex that serves as the building material of chromosomes.

Question 53

What is a chromosome?

Accepted Answer

A structure within the nucleus or nucleoid that is made up of chromatin that contains DNA, the hereditary material.

Question 54

What is cytoplasm?

Accepted Answer

The entire region between the plasma membrane and the nuclear envelope, consisting of organelles suspended in the gel-like cytosol, the cytoskeleton, and various chemicals.

Question 55

What is cytosol?

Accepted Answer

The gel-like material of the cytoplasm in which cell structures are suspended.

Question 56

What is a eukaryotic cell?

Accepted Answer

A cell that has a membrane-bound nucleus and several other membrane-bound compartments or sacs.

Question 57

What is a lysosome?

Accepted Answer

An organelle in an animal cell that functions as the cell's digestive component; it breaks down proteins, polysaccharides, lipids, nucleic acids, and even worn-out organelles.

Question 58

What are mitochondria?

Accepted Answer

Cellular organelles responsible for carrying out cellular respiration, resulting in the production of ATP, the cell's main energy-carrying molecule. Singular = mitochondrion.

Question 59

What is a nuclear envelope?

Accepted Answer

A double-membrane structure that constitutes the outermost portion of the nucleus.

Question 60

What is a nucleolus?

Accepted Answer

A darkly staining body within the nucleus that is responsible for assembling the subunits of the ribosomes.

Question 61

What is nucleoplasm?

Accepted Answer

Semi-solid fluid inside the nucleus that contains the chromatin and nucleolus.

Question 62

What is a nucleus?

Accepted Answer

A cell organelle that houses the cell's DNA and directs the synthesis of ribosomes and proteins.

Question 63

What is an organelle?

Accepted Answer

A compartment or sac within a cell.

Question 64

What is a peroxisome?

Accepted Answer

A small, round organelle that contains hydrogen peroxide, oxidizes fatty acids and amino acids, and detoxifies many poisons.

4: Cell Structure Flashcards

Studying Cells, Prokaryotic Cells, Eukaryotic Cells, the Endomembrane System and Proteins, the Cytoskeleton, Connections between Cells and Cellular Activities

Brainscape's Knowledge GenomeTM

4: Cell Structure Flashcards

Studying Cells, Prokaryotic Cells, Eukaryotic Cells, the Endomembrane System and Proteins, the Cytoskeleton, Connections between Cells and Cellular Activities

Brainscape's Knowledge Genome^TM