Questions
TOPIC: Cation exchange capacity (CEC) determination in soil  First of all, search and understand the...

TOPIC: Cation exchange capacity (CEC) determination in soil

 First of all, search and understand the meaning and the importance of the parameter in agriculture.

 Explain the analysis methods with details. If there are more than one methods, you must mention about the other methods as well.

 Find the limits and their meanings including the reference you used (Ex: 0-5 Low, 5-10 Medium, 10-15 High etc. (FAO, 2005)

 Do not forget to include your references.!

In: Biology

hi, regarding the electron transport chain: why when talking about NADH + H+, we talk about...

hi, regarding the electron transport chain:

why when talking about NADH + H+, we talk about giving electrons rather then proton? this really confuses me..

where is it more potonated and where more ionized? metrix or intracellular or extracellular?

Fe-Sulf is concidered what? I mean it recieves electrons and moves them forward so whats the name of this kind of molecule?

is NADH recruited by FMN? who makes it get to comples I?

thanks in advance

In: Biology

a) The term ‘amyloid’: Was coined by the German physician, Alois Alzheimer Generally refers to protein...

  1. a) The term ‘amyloid’:
  1. Was coined by the German physician, Alois Alzheimer
  2. Generally refers to protein aggregates of any form
  3. Protein aggregates that stain similarly to the polysaccharide, cellulose when exposed to iodine.
  4. None of the above.
  1. b) Which of the following is true about Tay Sachs disease? Choose all that apply.
  1. It results from an abnormal accumulation of the enzyme, HexA in lysosomes.
  2. It results in the abnormal accumulation of GM2 ganglioside inside lysosomes.
  3. It is caused by a mutation in a gene on chromosome 15.
  4. It can be caused when the HexA enzyme fails to get phosphorylated on one of its sugar residues.
  5. It results in the abnormal accumulation of GM2 ganglioside inside the Golgi.
  6. It can be caused when the HexA enzyme fails to get glycosylated in the ER.

1. c) Which of the following is not a common symptom or outcome of some forms of Tay Sachs disease?

  1. Seizures
  2. Low muscle tone
  3. Death before age 5
  4. Poor vision
  5. None of the above
  1. d) There are three major types of physiological consequences of protein misolfing.When a mutant protein misfolds and gets degraded in proteasomes, this is called a ____________.
  1. gain of toxic function
  2. loss of function
  3. infectious misfolding
  4. dual toxicity
  1. a) Mutations in the protein, alpha 1-antitrypsin cause (choose all that apply):
  1. it to accumulate in the ER of hepatocytes
  2. the release of proteases that damage liver tissue
  3. the uninhibited activity of a protease that damages lung tissue
  4. prohibit its proper localization to lung tissue

  1. b) True or False. Individuals who experience gradual onset of Tay Sachs symptoms are likely to be heterozygous for a HexA mutation.
  1. True
  2. False

In: Biology

In a test cross of a double heterozygote, each of the recombinant type gametes occurs at...

In a test cross of a double heterozygote, each of the recombinant type gametes occurs at a frequency of 15%. The expected frequency of each of the parental type gametes is

a) 15% b) 20% c) 35% d) 45% e) 50%

In: Biology

TRUE/FALSE Please indicate whether each question is true or false and provide a 1 sentence explanation...

TRUE/FALSE Please indicate whether each question is true or false and provide a 1 sentence explanation

5. Temperature is associated with terrestrial productivity. If the global temperature increased by 10C we would expect that grasslands would have an increase in both GPP and NPP.

6. In most ecosystems, the rate of phosphorous recycling through fixation exceeds the rate added through weathering.

7. An invasive insect called the Emerald Ash Borer has been killing off ash trees across eastern North America over the past several decades. This is likely to have reduced the GPP of the ecosystem over the course of the outbreak.

8. The current global population is roughly 7.5 billion people. The population would likely not be this high had Fritz Haber (and Carl Bosch) not invented the process for fixing atmospheric nitrogen into ammonia to make nitrogen fertilizer.

In: Biology

1) You sequence a gene of interest and isolate the matching mRNA. You find that the...

1) You sequence a gene of interest and isolate the matching mRNA. You find that the mRNA is considerably shorter than the DNA sequence. Why is that?

a) There was an experimental mistake. The mRNA should have the same length as the gene.
b) The mRNA should be longer than the DNA sequence because the promoter is also transcribed.
c) The processed mRNA is shorter because introns were removed.
d) The mRNA is shorter because the signal sequence to cross the nuclear membrane was removed.

2) Why is it necessary that meiosis occurs in sexually reproducing organisms?

a) to maintain the viability of the gametes
b) to ensure that genetic variation is reduced
c) to maintain a constant chromosome number in each generation
d) to ensure evolutionary success

3) Explain how a boy could have his mother’s nose and his father’s ears.

a) independent assortment of chromosomes
b) the movement of homologous pairs during meiosis
c) by receiving his father’s Y chromosome
d) inheritance of intact chromosomes from parents

4) There are multiple ways that the diversity of offspring from the same parents is enhanced. What is the contribution of metaphase I to this diversity?

a) the random orientation of tetrads at the metaphase plate
b) the random alignment of homologous chromosomes when they cross over
c) the formation of chiasmata when the homologous chromosomes line up at the equator
d) the formation of a synaptonemal complex during chromosomal synapsis

5) Describe the general conditions that must be met at each of the three main cell cycle checkpoints.

a) G1 checkpoint - assessment of DNA damage, G2 - assessment of new DNA, M checkpoint - segregation of sister chromatids in anaphase.
b) G1 checkpoint - Energy reserves for s phase, G2 checkpoint - assessment of new DNA, M checkpoint- attachment of spindle to kinetochore.
c) G1 checkpoint - assessment of DNA damage, G2 checkpoint - energy reserves for duplication, M checkpoint - attachment of spindle to kinetochore
d) G1 checkpoint - Energy reserves for S-phase, S checkpoint - synthesis of DNA, G2 checkpoint - assessment of new DNA

In: Biology

Briefly explain the differences between F+, F−, Hfr, and F′ cells. Generalized transduction by phage P1...

Briefly explain the differences between F+, F, Hfr, and F′ cells.

Generalized transduction by phage P1 of four E. coli genes (a, b, c, and d) shows the following percentages of cotransduction: a -- d 51%, d -- c 2%, b -- d 12%, a -- b 40%, a -- c 19%, c -- b 79%.

d a b c

a b c d

b d a c

b a c d

A wild-type strain (h+r+) of phage T2 was mixed with a double mutant (hr) for host range (h) and rapid lysis (r) and used with a high multiplicity of infection to infect E. coli B. The progeny from the cross were titered (counted) on a mixture of E. coli B and E. coli B/2 strains. The following plaques were scored:          hr,320; h+r,110; hr+,106; h+r+,290. What is the approximate recombination frequency for these two loci?

16 %

40 %

24 %

26 %

Briefly outline the history of our knowledge of the structure of DNA until the time of Watson and Crick. Which do you think were the principle contributions and developments?

In: Biology

Compare and contrast between the four types of hypersensitivity in detail

Compare and contrast between the four types of hypersensitivity in detail

In: Biology

Explain how extracellular matrix glycoproteins are produced, modified and moved to and eventually placed within the...

Explain how extracellular matrix glycoproteins are produced, modified and moved to and eventually placed within the EC matrix.  

In: Biology

I am looking for a detailed and well presented answer. Organize your work and think through...

I am looking for a detailed and well presented answer. Organize your work and think through the information. Make sure it is in your own words. You are expected to research the information. make sure to include your references.

What is the catalase test? Coagulase test?

What does it mean to be:

Catalase +

Catalase -

Coagulase +

Coagulase -

When working with an unknown that may be Staphylococcus (but you are not sure), how can the two tests help?

Give step by step detail of how to determine you are dealing with Staphylococcus and not an organism such as Streptococcus (next week topic).

Give step by step details on how to determine you are dealing with:

S. epidermidis

S. aureus

Please no handwritten or picture responses - only typed answers.

In: Biology

Digestive system what could be the purpose of cell junctions that fit together like jigsaw pieces?...

Digestive system
what could be the purpose of cell junctions that fit together like jigsaw pieces? consider that the intestinal muscles are often in motion, creating peristalsis.

In: Biology

Cancer cells have a high need for RNA, DNA, as well as energy (ATP) as they...

Cancer cells have a high need for RNA, DNA, as well as energy (ATP) as they rapidly divide. A precursor to the building blocks of RNA and DNA is Ribose-5-P (R-5-P). A high sugar diet has been shown to accelerate cancer growth. In terms of cellular metabolism, explain why a high sugar diet might be able to fulfill cancer cells high need for RNA, DNA, and ATP. For any metabolic pathways that intersect, be sure to identify the intermediate(s) that link the pathways.

In: Biology

how many atp are consumed by the glycolysis of a single molecule of glucose

how many atp are consumed by the glycolysis of a single molecule of glucose

In: Biology

Bacterial cells couple the process of transcription and translation. In eukaryotic cells, the process of transcription...

Bacterial cells couple the process of transcription and translation. In eukaryotic cells, the process of transcription and translation are uncoupled or occur separately. Provide explanations as to why bacterial cells can couple the process of transcription and translation while in eukaryotic cells, the process is separated.

In: Biology

Filo Porifera 6. Name the parts of the external and internal anatomy of the porifers. 7....

Filo Porifera
6. Name the parts of the external and internal anatomy of the porifers.
7. Mention the role of pinacocytes, coanocytes, amebocytes, and spicules on sponges.
8. Mention the type of nutrition that sponges exhibit.
9. Mention how gas exchange and excretion occur in sponges.
10. Explain the reproduction mechanisms exhibited by sponges.
11. Why are the sponges said to have arisen from a colonial protozoan ancestral organism?

In: Biology