BIOL120 Study Guide - Final Guide: Transmission Electron Microscopy, Scanning Electron Microscope, Ground Tissue

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sapphiremuskrat88

16 Dec 2017

School

University of Waterloo

Department

Biology

Course

BIOL120

Professor

Susan Lolle

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Document Summary

Cells are microscopic, enabling adequate absorption of oxygen, water, and nutrients through the cell"s surface to meet the needs of internal regions. Light microscopes bend light to produce magnified images. Electron microscopes focus electrons with magnetic lenses to produce images. The transmission electron microscope passes electrons through a specimen to produce television images. The scanning electron microscope bounces electrons off a specimen to yield a 3-d image. Eukaryotic cells evolved from prokaryotic cells and are generally larger and more complex, with an enclosed nucleus and other membrane-bound organelles. Most known prokaryotes are bacteria, which are single-celled organisms. Eukaryotes can be single-celled but most are multicellular, cellular functions are handled by organelles. Endosymbiotic theory states that some organelles evolved as a result of prokaryotic cells ingesting other prokaryotic cells. Protoplast is the interior of the cell (everything inside the cell wall), which consists of the nucleus and the cytoplasm.

Related Questions

1. You observe that small crustaceans swimming through a sample of ocean water set off light production, but your first guess is that this is due to some bacterium, since bacteria are so metabolically diverse. True or false

2. How did multicellular organisms evolve from unicellular organisms?

Single-celled organisms joined together, or failed to separate after cell division.

Single-celled organisms joined together only.

Single-celled organisms failed to separate after cell division only.

Single-celled organisms joined together, or absorbed other species by endosymbiosis.

One species absorbed another species by endosymbiosis only.

3.Cooperation between or among cells could have been a key step in the evolution of multicellularity.

True

False

4. Autotrophs must acquire carbon from organic molecules produced from other organisms.

True

False

5. The protists, though now known to have multiple origins, were first group due to their being aquatic, and, most of them, quite small.

True

False

6. You are analyzing samples under a microscope, and one sample coming from what you suspect is a fungus. You find tiny filaments, which, in your report, you call

hyphae.

spores.

fruiting bodies.

7. Fungi are classified into phyla based on which characteristic?

organelles

composition of cell wall

photosynthesis

reproductive structures

multicellular vs. unicellular

gills.

chitin.

You are studying two populations of dung beetles, one of which rolls their dung balls at noon, resting at night, and the other of which reverses this. These could speciate due to

behavioral isolation.

gametic isolation.

mechanical isolation.

temporal isolation.

sexual selection.

TAKING EXAM NOW, need fast please!

__________ are fairly small organelles that provide a safe place within the cell to carry out certain biochemical reactions that generate harmful, highly reactive oxygen species. These chemicals are both generated and broken down in the same location.

Lysosomes

Endosomes

Peroxisomes

Nucleosomes

Biologists cannot possibly study all living species. Instead, they try to understand cell behavior by studying a select subset of them. Which of the following characteristics are useful in an organism chosen for use as a model in laboratory studies?

rapid rate of reproduction

all of the above

ability to grow under controlled conditions

amenability to genetic manipulation

By definition, prokaryotic cells do not possess __________.

ribosomes.

a nucleus.

membrane bilayers.

replication machinery.

Cell biologists employ targeted fluorescent dyes or modified fluorescent proteins in both standard fluorescence microscopy and confocal microscopy to observe specific details in the cell. Even though fluorescence permits better visualization, the resolving power is essentially the same as that of a standard light microscope because the resolving power of a microscope is limited by the __________ of light.

intensity

absorption

wavelength

filtering

Choose the phrase that best completes this sentence: Microtubules ____________ and are required to pull duplicated chromosomes to opposite poles of dividing cells.

generate contractile forces

can rapidly reorganize

are found in especially large numbers in muscle cells

are intermediate in thickness

Despite the differences between eukaryotic and prokaryotic cells, prokaryotes have proteins that are distantly related to eukaryotic actin filaments and microtubules. What is likely to be the most ancient function of the cytoskeleton?

cell division

cell motility

vesicle transport

membrane support

DNA and RNA are different types of nucleic acid polymer. Which of the following is true of DNA but not true of RNA?

It contains thymine.

It has 5'-to-3' directionality.

It is single-stranded.

It contains uracil.

Double covalent bonds are both shorter and stronger than single covalent bonds, but they also limit the geometry of the molecule because they ____________________.

prevent additional bonds from being formed with the bonded atoms.

limit the rotation of the bonded atoms.

create a new arrangement of electron shells.

change the reactivity of the bonded atoms.

Drosophila melanogaster is a/an __________. This type of animal is the most abundant of all animal species, making it an appropriate choice as an experimental model.

mammal

amphibian

bird

insect

10.

If the isotope 32S has 16 protons and 16 neutrons, how many protons, neutrons, and electrons will the isotope 35S have, respectively?

16, 19, 17

16, 19, 15

16, 19, 16

16, 20, 15

11.

Living systems are incredibly diverse in size, shape, environment, and behavior. It is estimated that there are between 10 million and 100 million different species. Despite this wide variety of organisms, it remains difficult to define what it means to say something is alive. Which of the following can be described as the smallest living unit?

cell

organelle

protein

DNA

12.

Macromolecules in the cell can often interact transiently as a result of noncovalent interactions. These weak interactions also produce stable, highly specific interactions between molecules. Which of the factors below is the most significant in determining whether the interaction will be transient or stable?

the concentration of each molecule

the size of each molecule

surface complementarity between molecules

the rate of synthesis

13.

Many of the mechanisms that cells use for maintenance and reproduction were first studied at the molecular level in bacteria. Which bacterial species had a central role in advancing the field of molecular biology?

E. coli

S. pombe

C. elegans

D. melanogaster

14.

Many types of cells have stores of lipids in their cytoplasm, usually seen as fat droplets. What is the lipid most commonly found in these droplets?

cholesterol

isoprene

triacylglycerol

palmitic acid

15.

Mitochondria contain their own genome, are able to duplicate, and actually divide on a different time line from the rest of the cell. Nevertheless, mitochondria cannot function for long when isolated from the cell because they are __________________.

anaerobes.

viruses.

parasites.

endosymbionts.

16.

Mitochondria perform cellular respiration, a process that uses oxygen, generates carbon dioxide, and produces chemical energy for the cell. Which answer below indicates a correct pairing of material âburnedâ and the form of energy produced during cellular respiration?

17.

Polar covalent bonds are formed when the electrons in the bond are not shared equally between the two nuclei. Which one of these molecules contains polar bonds?

Material Science

Question 1

Muscle fibers slide smoothly across each other in both directions.

True

False

Question 2

Cell membranes are composed of single layers of fat molecules.

True

False

Question 3

In mammals, the percentage composition of fats and minerals is roughly the same.

True

False

Question 4

Both RNA and DNA have a double helix structure.

True

False

Question 5

The primary constituents of muscles are

	a)	the proteins kerotin and actin
	b)	the proteins lycine and actin
	c)	the proteins actin and liposine
	d)	the proteins glycine and lycine
	e)	the proteins myocin and actin

Question 6

Hydroxyapatite is a component of endoskeletons.

True

False

Question 7

There are thousands of types of amino acids.

True

False

Question 8

Amorphous silicon is a component of some biomaterials.

True

False

Question 9

The biosynthesis of both collagen and polysaccharides starts in the cell nucleus.

True

False

Question 10

After going through alkyline hydrolysis, the remaining solids are primarily hydroxyapatite.

True

False

Question 11

Calcium carbonate is a mineral found in some biomaterials.

True

False

Question 12

Proteins, chitin, and cellulose are build up from proteins

True

False

Question 13

There are thousands of types of proteins.

True

False

Question 14

Chitin is the most abundant natural polymer.

True

False

Question 15

Keratin is formed from a structure of living cells.

True

False

Question 16

Some biopolymers are hard.

True

False

Question 17

Polymeric biomaterials are comprised of collagen and elastin.

True

False

Question 18

Cell membranes are made of double layers of proteins.

True

False

Question 19

Which is NOT an example of a hard biopolymer?

		a)Eggs
		b)Insect Shells
		c)Hooves
		d)Nails
		e)Cellulose

Question 20

Polysaccharides are built up hierarchically from amino acids.

True

False

Question 21

Unit cells have faces that are

	a)	rhombus
	b)	square
	c)	rectangular
	d)	parallelegrams
	e)	circular

Question 22

Unit cells are

		a)the building blocks of crystalline material
		b)the building blocks of DNA
		c)the building blocks of polymers
		d)the building blocks of amorphous materials
		e)the building blocks of biomaterials

Question 23

Which radioactive semi-metal is the only element with a Simple-Cubic (SC) structure?

		a)Polonium
		b)Uranium
		c)Radium
		d)Plutonium
		e)Dilthium

Question 24

The common crystal structures in metal are

		a)FCC, BCC, HCP
		b)FCC, BCC, HCP, and SC
		c)HCC, BCC, FCP
		d)HCC, BCC, FCP and SC
		e)FCC, SEC, BCC

Question 25

Diffraction results in

		a)constructive interference
		b)delamination of the planes
		c)reverse polarization
		d)altered planar spacing
		e)destructive interference

Question 26

Unit cell indexing schemes provide

		a)location information for grain boundaries
		b)descriptions of the atoms, planes, and axis directions
		c)diffraction indexes for the crystal material
		d)the location of the unit cell in the larger crystalline matrix
		e)the packing arrangement

Question 27

Hexagonal crystal structures cannot be close-packed.

True

False

Question 28

To determine crystal structure and spacing, scientists use

		a)magnetic resonance imaging
		b)X-ray diffraction
		c)optical microscopes
		d)scanning electron microscopes
		e)atomic force microscopes

Question 29

A scanning probe (aka atomic force) microscope can be used to image and manipulate individual atoms.

True

False

Question 30

Crystal planar density is taken as

		a)the number of atoms per unit area for a plane
		b)the planar stacking order
		c)the number of atoms that are closely packed
		d)the number of equivalent atoms per unit cell
		e)the number of atoms per unit length for an axis

Question 31

The atomic packing factor represents

		a)the mass ratio of the unit cell
		b)the number of nearest-neighbor atoms
		c)the fraction of solid sphere volume in the unit cell
		d)the unit cell edge length (a) divided by the atomic radius (R)
		e)the density of the material

Question 32

When an elemental solid can have more than one crystal structure, it is said to have

		a)allotropy
		b)polymorphism
		c)polytropy
		d)elemorphism
		e)anthropomorphis

Question 33

The crystallographic linear density

		a)is determined by the atomic packing factor
		b)is six for HCP unit cells
		c)is five for BCP unit cells
		d)is determined by the coordination number
		e)is how many atoms lie along a unit length in that direction

Question 34

Bragg's law specifies

		a)the condition for when electrons will be refracted upon striking a crystal
		b)the condition for when light will be polarized upon striking a crystal
		c)the condition for when x-rays will be absorbed upon striking a crystal
		d)the condition for when x-rays will be refracted upon striking a crystal
		e)the condition for when light will be refracted upon striking a crystal

Question 35

Two features of a crystal unit cell structure are

		a)atomic number and elemental packing factor
		b)the number of interstitial and host atoms
		c)coordination number and atomic packing factor
		d)the number of faces and the number of atoms
		e)the number of substitutional and interstitial atoms

Question 36

Imperfections in semiconductors are used to create transistors and other electronic devices.

True

False

Question 37

The majority of crystalline solids are single crystals

True

False

Question 38

The grain structure of a polycrystalline material can be observed in the material without significant preparation.

True

False

Question 39

There are three types of electron microscopes, Transmission (TEM), Scanning (SEM), and Tunneling (TUEM).

True

False

Question 40

Defects are important for solid catalysts

True

False

Question 41

The mean intercept length is a measure of grain diameter.

True

False

Question 42

Imperfections in materials do not generally change their properties.

True

False

Question 43

The mean intercept length is computed from the average length of a grain boundary edge.

True

False

Question 44

Catalysts chemically combine with the reactant molecules in order to speed up the reaction.

True

False

Question 45

For a particular material, the higher the temperature the greater the number of vacancies.

True

False

Question 46

A twin boundary is a linear defect where the screw angles on each side of the boundary are equal.

True

False

Question 47

The regular pattern of crystal order is disrupted at a grain boundary.

True

False

Question 48

Solid solutions can only be formed by liquid material cooling to a solid.

True

False

Question 49

Alloys do not usually have significantly difference properties of the constituent metals.

True

False

Question 50

When an atom is missing from a crystal structure position, it is referred to as a self-interstitial.

True

False

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BIOL120 Study Guide - Final Guide: Transmission Electron Microscopy, Scanning Electron Microscope, Ground Tissue

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