Exam 1

Question 1

In your own multicellular body, different cells in your body have a division of labor between them.

Answer 1

True

Question 2

In Cell Biology what can limit the progress of science?

Answer 2

Technology

Question 3

The paramecium swims by way of using a flagella.

Answer 3

False

Question 4

In order to examine cells which are smaller than can be detected by the human senses what needs to be used?

Answer 4

Technology

Question 5

Comparing a single-celled eukaryotic organism with a multicellular organism such as yourself identify the major difference from the list below.

Answer 5

Division of labor

Question 6

The contractile vacuole of the paramecium is possibly an evolutionary precursor of the kidney.

Answer 6

True

Question 7

Write a few sentences that explain what limits an individual cell from becoming more complex.

Answer 7

An individual cells complexity is limited by several factors. Firstly the cells size must remain within a certain range to efficiently exchange nutrients and waste, which constrains the amount of internal structures it can accommodate. Additionally, a cells complexity is influenced by its specific function; cells adapt to perform their designated tasks efficiently, limiting their development to what’s necessity. Genetic factors also play a role, as a cells DNA contains instructions for its structure and function. Evolutionary pressures further shape cell complicity, factoring changes that enhance survival and reproduction while constraining unnecessary complexity.

Question 8

What 3 things entail A single-celled eukaryotic organism:

Answer 8

Has a limited number of biomolecular machines.

Must find food, shelter, a mate and reproduce

Escape from predators

Question 9

Compared to bacteria which of the cell types below are not responsible for finding food”

Answer 9

Lymphocyte

Macrophage

Fibroblast

Question 10

What limits the paramecium from acquiring more complex functions?

Answer 10

The limitations on paramecium’s complexity stem from their size, ecological specialization, and evolutionary pressures that prioritize traits relevant to their survival and reproduction within their niche

Question 11

In your own multicellular body, cells with different functions have different DNA.

Answer 11

False

Question 12

The paramecium discussed in class contained an organelle called the contractile vacuole. This is the presumed precursor of the:

Answer 12

Kidney

Question 13

A cell that is itself an organism must have a minimum of four needs presented in lecture. List these four things.

Answer 13

1. Cell membrane (plasma Membrane)
   
   2. Genetic Material (DNA or RNA)
   3. Metabolic Machinery
2. Reproduction Capability

Question 14

Why is it important to know the limitations of technology?

Answer 14

to see where our advantages are versus where we need to improve to gather more information better

Question 15

The cytoskeleton gave rise to the nuclear envelope.

Answer 15

False

Question 16

TEM provides a thin, two-dimensional section of the object being studied

Answer 16

True

Question 17

Finish the sentence based on my lectures: The association of ribosomes with _________________ invaginations would support the ______________ theory.

Answer 17

Membrane
Endosymbiotic

Question 18

Loss of the cell wall was required for the endomembrane system theory.

Answer 18

True

Question 19

The end of the retraction fiber touching the cell culture plate still contains the cell equivalent of super-glue.

Answer 19

True

Question 20

DNA in extant prokaryotic cells is circular.

Answer 20

False

Question 21

Loss of the cell wall is required for the endosymbiotic theory.

Answer 21

True

Question 22

The cytoskeleton enabled the primitive cell to become motile.

Answer 22

True

Question 23

When cancer cells are crowded by surrounding cells, the cancer cells become spherical and they can still go through cell division.

Answer 23

True

Question 24

Ribosomes bound to some of the membrane invaginations in the endomembrane theory.

Answer 24

True

Question 25

A normal cell is ____________and _________________for growth.

Answer 25

Regulated and controlled

Question 26

List one limitation of the cell culture technique.

Answer 26

They may not fully replicate the complex physiological conditions and interactions that occur within a living organism. In vitro cell cultures often lack 3D structure and intricate cell-cell and cell-environment interactions found in vivo, which can limit the accuracy of experimental results and the ability to model certain biological processes accurately

Question 27

The ancient earth did not contain much oxygen.

Answer 27

True

Question 28

The presumed first step in the transition of the primitive, proto-prokaryotic cell into the primitive, proto-eukaryotic cell was the loss of the cell wall.

Answer 28

True

Question 29

After a cell is pancake shaped in a cell culture dish, the order of events that occurs as a cell walks is (pick the best order):

Answer 29

Filapodia, lamellipodia, cell muscle, retraction fiber.

Question 30

Motility improved the fitness of these early cells because:

Answer 30

It allowed them to move away from predators and towards food.

Question 31

Fluorescence microscopy is a form of light microscopy.

Answer 31

True

Question 32

In an extant prokaryotic cell, the outer boundary of life is the capsule.

Answer 32

False

Question 33

What limits how big a cell can be?

Answer 33

The surface area to volume ratio

Question 34

It is presumed that the peroxisomes evolved in these primitive, proto-eukaryotes to remove oxygen, which was toxic to the primitive cells.

Answer 34

True

Question 35

A cell that is anchorage-dependent for growth will also exhibit contact inhibition.

Answer 35

True

Question 36

A cancer cell will be anchorage-dependent for growth and immortal.

Answer 36

False

Question 37

A normal cell is anchorage-dependent for growth and mortal.

Answer 37

True

Question 38

The ER (endoplasmic reticulum) is contiguous with the Golgi apparatus.

Answer 38

False

Question 39

A single pass trans-membrane protein that is an alpha helix can make a channel.

Answer 39

False

Question 40

Explain how the vesicles are carried from the Golgi apparatus to the plasma membrane.

Answer 40

Vesicles transport molecules from the Golgi apparatus to the plasma membrane via exocytosis

Question 41

If something is soluble in water and a shell of hydration forms around it, it is termed ___________________ .

Answer 41

hydrophilic

Question 42

Amino acids can be largely subdivided into two groups. What are the two groups?

Answer 42

Essential and non-essential amino acids

Question 43

The plasma membrane gets new lipids from:

Answer 43

lipid synthesis, lipid transport within the cell, uptake from external sources, recycling of internal lipids

Question 44

We are made up of ______ percent water.

Answer 44

60%

Question 45

Facilitated diffusion uses a channel protein to let components move down their concentration gradient.

Answer 45

True

Question 46

It is a simple matter (i.e., thermodynamically favorable) for a vesicle to form from the endoplasmic reticulum.

Answer 46

False

Question 47

What are the orphaned organelles orphaned from?

Answer 47

endocytosis

Question 48

Explain the evolutionary origin of the endoplasmic reticulum, Golgi apparatus and vesicles.

Answer 48

Endosymbiosis, one prokaryotic cell engulfed another leading to a symbiotic relationship

Question 49

What is the difference between a single-pass transmembrane protein and a 7-pass transmembrane protein?

Answer 49

The number of times that they span the cell membrane. Single pass proteins have one transmembrane domain while 7 pass proteins have seven transmembrane domains. This structural difference reflects their distinct functions in cellular signaling, with a single pass proteins often involved in specific ligand binding and transport, and 7pass proteins mainly serving as receptors for signal transduction

Question 50

Active transport uses ATP (Adenosine Triphosphate {cell energy currency}) to move components in parallel with their concentration gradient, that is: from a high concentration to a low concentration.

Answer 50

False

Question 51

Explain the evolutionary origin of mitochondria.

Answer 51

endosymbiosis of an ancestral aerobic bacterium within an early eukaryotic cell.

Question 52

What is the difference between a triglyceride and a phospholipid?

Answer 52

Triglycerides are used for energy storage within the cell that have glycerol and 3 fatty acid chains. Phospholipids form a bilayer in the cell membrane and acts as a barrier to their external environment

Question 53

Draw a phospholipid and make sure the numbers of carbons are clearly identified.

Answer 53

R l O l P l O l CH2-CH-CH2 l l O O l l C=O C= O -------------------------------- fatty acid chains < > > < < > > < < >--------------unsaturated fatty acids

Question 54

Cholesterol is _____ to have in biological membranes.

Answer 54

present

Question 55

The ER is contiguous with the nuclear envelope.

Answer 55

True

Question 56

For a protein to enter the endoplasmic reticulum as part of the endoplasmic reticulum’s lumen or part of the endoplasmic reticulum’s membrane:

Answer 56

A ribosome binds to the mRNA and a short stretch of protein is synthesized that contains a signal sequence.

Question 57

What are the two functions of a membrane?

Answer 57

Selective Permeability Compartmentalization

Question 58

When a vesicle fuses with the plasma membrane the contents of the lumen of the vesicle are:

Answer 58

Ligands that become the part of the plasma membrane. Ligands that are used in cell communication.

Question 59

Where is the histone H1 found?

Answer 59

In the Nucleosome core, where the H1 is acting as sort of a staple.

Question 60

Consider the geography of cells. Actin filaments are present in the cell’s ___ and the microtubules are present in the cell’s .

Answer 60

cortex

Question 61

To get into the nucleus a component has to have the correct signal sequence and pass through a nuclear pore.

Answer 61

True

Question 62

Molecular motors run on which two cytoskeletal filament systems?

Answer 62

Microtubules and actin filaments

Question 63

Heterochromatin does not exist in interphase nuclei.

Answer 63

False

Question 64

The diameter of an intermediate filament is 25 nm.

Answer 64

False

Question 65

Which cytoskeletal filament system lines the inside of the nucleus to protect it?

Answer 65

Nuclear lamina

Question 66

What does the nucleosomal core have in it (i.e., the basket ball like structure on the slides)?

Answer 66

Histone octamer, DNA, Histone H1

Question 67

Naked DNA does not exist in Nature but scientists can make naked DNA in a test tube.

Answer 67

True

Question 68

The actin filament system is present in the nucleus.

Answer 68

False

Question 69

Chromosomes are made out of Euchromatin.

Answer 69

False

Question 70

The actin filament system extends outside of the cell.

Answer 70

False

Question 71

Cilia and microvilli contain a similar number of parallel actin filaments.

Answer 71

False

Question 72

Molecular motors use ATP as the energy source to power the molecular motors.

Answer 72

True

Question 73

For a cell to respond to a ligand released from a cell and uses the circulatory system to get to the responding cell it is called ____________ communication.

Answer 73

endocrine

Question 74

When insulin binds to a receptor, this signal first uses ____________.

Answer 74

Tyrosine phosphorylation

Question 75

There are two types of receptors. One type of receptor binds to polar (hydrophilic) ligands and this is the receptor located in the ____________ ____________ (two words).

Answer 75

Plasma membrane

Question 76

There are two basic types of communication within cells. One type is called ____________ signaling and it takes days to weeks to occur. The other type is called _________ communication and it takes minutes to hours to act.

Answer 76

endocrine paracrine

Question 77

The other point where MAPK can become active is ____________ of the cell cycle.

Answer 77

G1 phase

Question 78

There is communication between cells and communication ____________ cells.

Answer 78

within

Question 79

There are two basic forms of cytoplasmic signaling (i.e. signal transduction). One uses ____________ and the other uses ____________.

Answer 79

chemical signaling electrical signaling

Question 80

Two types of second messengers discussed in lecture can exist downstream of a plasma membrane receptor. These are ____________ and ____________.

Answer 80

cyclic AMP Calcium Ions

Question 81

For a cell to respond to a ligand released from a neighboring cell where the ligand diffuses directly from one cell to another is called ____________ communication.

Answer 81

paracrine

Question 82

MAPK has two different functions depending on where this kinase acts in the ____________ ____________(two words). If the kinase becomes active during interphase the cell is triggered to progress through the ____________ ____________(two words).

Answer 82

cell cycle G1 phase

Question 83

When a cell “talks to itself” it is called ____________ communication.

Answer 83

autocrine

Question 84

The synthesis/presence of cyclin is what turns on the Cdk as the Cdk is always present but it is the cyclin that is synthesized and degraded in cycles.

Answer 84

True

Question 85

During mitosis, the cytoplasm of the cell is “settled down”.

Answer 85

False

Question 86

The _________ begins to be destroyed at the metaphase of the cell cycle causing the chromosomes to begin to _________.

Answer 86

Mitotic spindle separate

Question 87

Cytoplasmic signal transduction controls the checkpoints of the cell cycle.

Answer 87

True

Question 88

The activation of both MPF and MAPK result in _________ _________ (two words) of the cytoplasm during M-phase.

Answer 88

cytoskeletal reorganization

Question 89

Cytokinesis in plant and animal cells takes two forms. List them here.

Answer 89

Animal Cell cytokinesis: Cleavage to form a contractile ring Plant Cell Cytokinesis: cleavage to form a structure called cell plate

Question 90

Many chemotherapy drugs act by arresting the cell in M-phase of the cell cycle.

Answer 90

True

Question 91

After DNA synthesis (i.e., S-phase) an identical copy of the DNA has been made and this is present in the two chromatids when viewed as the chromosome.

Answer 91

True

Question 92

Cancer can be described as a loss of cell cycle regulation.

Answer 92

True

Question 93

In the time span of 10 years every cell in your adult body goes through the cell cycle.

Answer 93

False

Question 94

An important checkpoint regulator is at the Gap2/M-phase transition. Here cyclin B and Cdk1 activate and form MPF which becomes a _________ _________ (two words) and causes the DNA to condense into _________.

Answer 94

protein kinase chromosomes

Question 95

List the three categories of cells in the body with regard to the cell cycle.

Answer 95

interphase, Mitotic phase, cytokinesis

Question 96

In your body not all cells go through the cell cycle.

Answer 96

True

Question 97

At these checkpoints, a cyclin works with a cyclin-dependent kinase (i.e., Cdk) to regulate the checkpoint.

Answer 97

True

Question 98

Gap1 of the cell cycle represents the time when the cell is doing what it is supposed to do as part of its cell type. In other words, that is when a liver cell is doing its function as a liver cell.

Answer 98

True