Cell Biology

Genetics cross

Genetics cross

In labrador retrievers, black coat (B/-) is dominant to brown coat (b,b). A breeder crosses two black individuals who have previously produced some brown puppies. If the cross produces  six puppies:

a) what is the probablity that the

adfadfa   1418   3 Replies

adfadfa

all would result in change in frequency of a specific allele in a pop. except?

all would result in change in frequency of a specific allele in a pop. except?

All of the following would result in the change in the frequency of a specific allel in a population except...

A. Selection against the recessive genotype
B. selection against the dominant phenotype
C. Genetic drift
D. Rand

3241993   2136   1 Reply

duddy

If steroid hormones must be bound to protein carriers to travel through the bloo

If steroid hormones must be bound to protein carriers to travel through the bloo

If steroid hormones must be bound to protein carriers to travel through the blood, how are they able to bind to intracellular receptors? (The protein carriers cannot diffuse through the membrane.)   

colleen   1654   1 Reply

duddy

Actin and myosin interactions are utilized in many types of movement, including

Actin and myosin interactions are utilized in many types of movement, including

Actin and myosin interactions are utilized in many types of movement, including the movement generated by muscles. Explain how the movement of myosin down an actin filament can generate contraction of a muscle.   

colleen   812   1 Reply

robertling

Microtubules are important as structural proteins. They may be used to support t

Microtubules are important as structural proteins. They may be used to support t

Microtubules are important as structural proteins. They may be used to support the cell, as pathways for the movement of motor proteins, and to ensure the even division of chromosomal material during mitosis. Thus, having the ability to regulate the

colleen   812   1 Reply

robertling

Movement of any type in an organism depends on the cytoskeleton and motor protei

Movement of any type in an organism depends on the cytoskeleton and motor protei

Movement of any type in an organism depends on the cytoskeleton and motor proteins found in the cell. Discuss the three general categories of movement, how they physically occur, and give an example of how each may be used.   

colleen   1210   1 Reply

robertling

There are some neurotransmitters, such as acetylcholine, that are used extensive

There are some neurotransmitters, such as acetylcholine, that are used extensive

There are some neurotransmitters, such as acetylcholine, that are used extensively throughout the nervous system. Yet a single type of neurotransmitter can have multiple effects. How is this possible?   

colleen   786   1 Reply

robertling

A high speed of conduction along axons is very important for the survival of org

A high speed of conduction along axons is very important for the survival of org

A high speed of conduction along axons is very important for the survival of organisms, particularly when quicker response times allow escape from a predator. Many factors affect speed of conduction, including temperature, myelination, and the diamet

colleen   685   1 Reply

robertling

Glial cells were originally thought to play a very minor role in the nervous sys

Glial cells were originally thought to play a very minor role in the nervous sys

Glial cells were originally thought to play a very minor role in the nervous system. In fact, their name is derived from the Greek word for glue. However, recent findings have demonstrated a number of functions for these cells. Discuss these function

colleen   828   1 Reply

robertling

Hormones are chemicals that are released into the blood and travel all over the

Hormones are chemicals that are released into the blood and travel all over the

Hormones are chemicals that are released into the blood and travel all over the body where they can have effects on their target cells. Discuss the mechanisms that allow only the target cells to respond and how target cells may have very different re

colleen   684   1 Reply

robertling

You have isolated two neurons, joined by a synapse, in a Petri dish. You have st

You have isolated two neurons, joined by a synapse, in a Petri dish. You have st

You have isolated two neurons, joined by a synapse, in a Petri dish. You have stimulated the first neuron at the axon hillock and successfully generated an action potential. However, there is no response by the postsynaptic neuron. Describe possible

colleen   1171   1 Reply

robertling

The absolute and relative refractory periods of an action potential determine ot

The absolute and relative refractory periods of an action potential determine ot

The absolute and relative refractory periods of an action potential determine other parameters of action potentials such as causing unidirectional conduction and limiting their frequency. Describe what is happening during each of the refractory perio

colleen   2708   1 Reply

robertling

Compare and contrast positive and negative feedback loops.

Compare and contrast positive and negative feedback loops.

Compare and contrast positive and negative feedback loops.   

colleen   7680   1 Reply

robertling

There is a tremendous variety of signal transduction pathways with a wide range

There is a tremendous variety of signal transduction pathways with a wide range

There is a tremendous variety of signal transduction pathways with a wide range of functions. However, all these pathways have some things in common. Discuss some of these common features. 

colleen   790   1 Reply

robertling

Once a ligand has bound to a receptor, it will continue to generate its response

Once a ligand has bound to a receptor, it will continue to generate its response

Once a ligand has bound to a receptor, it will continue to generate its response. In order to stop that response, the ligand must be removed or inactivated in some way. Describe the different ways this may be accomplished, along with features of each

colleen   768   1 Reply

robertling

Does anybody have notes on Molecular Biology of the Cell 5E Alberts Chapter 4?

Does anybody have notes on Molecular Biology of the Cell 5E Alberts Chapter 4?

Not just ppt slides but comprehensive notes?

nmfbmail   2725   1 Reply

robertling

Microbial growth factors hemin and NAD+

Microbial growth factors hemin and NAD+

Hi,

This is from Microbiology: An Intro 10th ed. by Tortora, Funke, Case. Clinical Applications Ch. 5, p. 155:

#1. Haemophilus influenze requires hemin (X factor) to synthesize cytochromes and NAD+ (V factor) from other cells. F

microbeman   2963   2 Replies

a

Action of amphotericin B against bacterial/fungal infections and side effects.

Action of amphotericin B against bacterial/fungal infections and side effects.

Hi,

This is from Microbiology: An Intro 10th ed. by Tortora, Funke, Case. Clinical Applications Ch. 2, p. 53:

#4. The antibiotic amphotericin B causes leaks in cells by combining with sterols in the plasma membrane. Would

microbeman   8115   3 Replies

a

Viral Mechanism

Viral Mechanism

Hi,

When a virus infects a cell, it uses a mechanism to prevent any other kind of virus from infecting that cell. What is that mechanism? How does it work?

Thankyou.

mafhh   1878   6 Replies

mafhh

wavelengths and chloroplasts? HELP please!

wavelengths and chloroplasts? HELP please!

In your work for a plant biotechnology company you have developed a new compound with unusual properties.  When you incubate isolated chloroplasts in this compound (called “X”), it accumulates in the thylakoid lumen and nowhere else in the organ

daniellekille   1338   1 Reply

ppk

Water has many unique properties. Can you identify the property of water that is

Water has many unique properties. Can you identify the property of water that is

Water has many unique properties. Can you identify the property of water that is responsible for each of the following observations?
a. Many insects, such as the water strider, are able to move across the surface of water.
b. Most people ge

colleen   3381   1 Reply

bio_man

5'-ATAGGGCTT-3' is a short sequence of a strand of DNA. What will be the complem

5'-ATAGGGCTT-3' is a short sequence of a strand of DNA. What will be the complem

5'-ATAGGGCTT-3' is a short sequence of a strand of DNA. What will be the complementary sequence of the other strand? What will be the complementary mRNA sequence derived from the second strand of DNA? Be sure to indicate the 5' or 3�

colleen   1305   1 Reply

bio_man

Starch, cellulose, and glycogen are all polysaccharides composed of glucose. Wha

Starch, cellulose, and glycogen are all polysaccharides composed of glucose. Wha

Starch, cellulose, and glycogen are all polysaccharides composed of glucose. What makes each of these polysaccharides unique in spite of the fact that all are composed solely of glucose?

colleen   3853   1 Reply

bio_man

How would you utilize silencing and microRNAs in a gene therapy treatment for a

How would you utilize silencing and microRNAs in a gene therapy treatment for a

How would you utilize silencing and microRNAs in a gene therapy treatment for a single-gene genetic disorder?

colleen   983   1 Reply

bio_man

For each of the three basic macromolecules (proteins, polysaccharides, and nucle

For each of the three basic macromolecules (proteins, polysaccharides, and nucle

For each of the three basic macromolecules (proteins, polysaccharides, and nucleic acids), identify the monomer, its activated/carrier form, and the directionality of the molecule.

colleen   1131   1 Reply

bio_man

Describe how the amphipathic nature of phospholipids leads to the formation of t

Describe how the amphipathic nature of phospholipids leads to the formation of t

Describe how the amphipathic nature of phospholipids leads to the formation of the phospholipid bilayer organization observed in membrane structure. Based upon this information, how would you design a drug delivery system to cross the cell membrane?

colleen   2157   1 Reply

bio_man

Describe the ways in which cell membranes are semipermeable.

Describe the ways in which cell membranes are semipermeable.

Describe the ways in which cell membranes are semipermeable.

colleen   826   1 Reply

bio_man

Match each scientist or group of scientists on the left with the appropriate sta

Match each scientist or group of scientists on the left with the appropriate sta

Match each scientist or group of scientists on the left with the appropriate statement to the right.

A) hereditary factors
B) pollen grain
C) chromosome theory of heredity
D) dog saliva
E) "ferments" of yeast

colleen   969   1 Reply

bio_man

Scientific discoveries have had great impact in human history. The people who ma

Scientific discoveries have had great impact in human history. The people who ma

Scientific discoveries have had great impact in human history. The people who make these discoveries and the circumstances that surround these discoveries are very important to our understanding of science. Can you identify the individuals as they mi

colleen   2330   1 Reply

bio_man

A number of different types of microscopy exist. Each type of microscopy has adv

A number of different types of microscopy exist. Each type of microscopy has adv

A number of different types of microscopy exist. Each type of microscopy has advantages and disadvantages. Can you identify the microscope that would be most advantageous for the situation below?
a. A cell biologist wishes to visualize the ribos

colleen   1448   1 Reply

bio_man

You have identified a new cytokine associated with the immune system that drasti

You have identified a new cytokine associated with the immune system that drasti

You have identified a new cytokine associated with the immune system that drastically reduces cell division by lymphoma cells in vivo. Develop a hypothesis and design an experiment to test your hypothesis using a model organism. Include an explanatio

colleen   641   1 Reply

bio_man

You have been a sample of Mimivirus, which has the largest capsid diameter of al

You have been a sample of Mimivirus, which has the largest capsid diameter of al

You have been a sample of Mimivirus, which has the largest capsid diameter of all currently known viruses (600 nm) and is hexagon shaped (icosahedral). Based on your knowledge of microscopes, what would you be able to see/determine about mimiviral st

colleen   747   1 Reply

bio_man

A transmembrane protein has 1000 amino acids. The fifth amino acid is found on t

A transmembrane protein has 1000 amino acids. The fifth amino acid is found on t

A transmembrane protein has 1000 amino acids. The fifth amino acid is found on the external surface of the cell membrane. It interacts with the aqueous environment outside the cell. Amino acids 25 and 205 are covalently bonded to each other and are r

colleen   6941   1 Reply

bio_man

As a protein is being synthesized, the correct folding of the protein is aided b

As a protein is being synthesized, the correct folding of the protein is aided b

As a protein is being synthesized, the correct folding of the protein is aided by the movement of nonpolar amino acids toward the inner areas of the protein. How can this phenomenon be explained? How will this influence other levels of protein struct

colleen   2042   1 Reply

bio_man

Within human lungs, the apical surface of the epithelium produces a growth facto

Within human lungs, the apical surface of the epithelium produces a growth facto

Within human lungs, the apical surface of the epithelium produces a growth factor called heregulin. The receptors for heregulin are located on the basolateral surface of the same cells. When the lung epithelial lining is intact, the tight junctions c

colleen   943   1 Reply

bio_man

In your own words and with your own examples, explain fully how cells are limite

In your own words and with your own examples, explain fully how cells are limite

In your own words and with your own examples, explain fully how cells are limited in size and how some cells have modifications that allow them to be larger or more adapted to a particular function in spite of these limitations.

colleen   775   1 Reply

bio_man

A microbiologist has discovered what she thinks are two new types of algae. The

A microbiologist has discovered what she thinks are two new types of algae. The

A microbiologist has discovered what she thinks are two new types of algae. The first cell (organism 1) appears nearly cubic and is approximately 1.5 ?m wide × 1.5 ?m long × 1.5 ?m deep. The second, longer cell (organism 2) is 2 ?m wide × 5 ?m long ×

colleen   1126   1 Reply

bio_man

In your own words, describe how energy flows through an ecosystem and how this c

In your own words, describe how energy flows through an ecosystem and how this c

In your own words, describe how energy flows through an ecosystem and how this contributes to a continuous increase in enthalpy.

colleen   1591   1 Reply

bio_man

Identify each of the following examples as phototrophs or chemotrophs. If the ex

Identify each of the following examples as phototrophs or chemotrophs. If the ex

Identify each of the following examples as phototrophs or chemotrophs. If the example is a chemotroph, indicate whether the needs of the chemotroph are met with or without oxygen (aerobic and anaerobic).
a. A pine tree grows in a forest.
b.

colleen   2329   1 Reply

bio_man

Enzyme activity may be regulated by several means. Can you identify the mode of

Enzyme activity may be regulated by several means. Can you identify the mode of

Enzyme activity may be regulated by several means. Can you identify the mode of regulation for each of the following examples?
a. When glucose is converted to glucose-6-phosphate by hexokinase, the accumulation of glucose-6-phosphate inhibits th

colleen   1483   1 Reply

bio_man