Consider an ecological niche with three species A, B and C. Their dynamics are given by their population rates shown below

dA/dt=A+B-C … (2a)

dB/dt=-A+2B … (2b)

dC/dt=C-A-B … (2c)

Initially, the niche is in equilibrium with the population of C=30. Obtain the population densities of the rest of participants in the niche at its equilibrium. Starting from the point (A=8,B=4,C=10), obtain their individual populations over time t. What if the initial starting point is perturbed to (A=7,B=4,C=10)? Would the system emerge in the same way?

1. Prepare t-accounts for cash A/R, the allowance for DA, and income statement

2. Prepare journal entries for each situation

3. Find Net Accounts receivable

A company begins business on 1/1/2019

Information for January:

Bad debt expense is 3% of credit sales using the percentage of sales method (total credit sales * estimate percentage).

No accounts were written off.

At the end of January, the company reviews A/R and decides that $4000 of ending A/R will NOT be collectable.

(make the adjusting entry needed to create the allowance balance.)

Summarize in one line the cou have been caught outside in a snowstorm for a few days now. Your incredible survivor’s skills enabled you to build a wonderful igloo. Yet, your only chance for survival is to drink some melted snow to avoid dehydration. Unfortunately, you know that that this snow is spiked with 10mM of a very potent toxin, Brooklycidin with a molecular weight of 500 Da (g/mol). The lethal dose of Brooklycidin for humans is 10mg/kg of bodyweight. How much volume of melted snow can you drink before reaching the lethal dose? Would it enable you to survive? *

Mona Lisa (also known as La Gioconda) is a 16th century portrait painted in oil on a poplar panel by Leonardo da Vinci during the Italian Renaissance. The work is owned by the Government of France and is on the wall in the Louvre in Paris, France with the title Portrait of Lisa Gherardini, wife of Francesco del Giocondo.

According to Aristotle all existing things go from potential to actual. For this painting write a paragraph explaining:

What is the primary substance? What is the secondary substance? How does the painting move from potential to actual. What are the four causes and what are the four causes for this painting?

Multichannel detectors like diode arrays and CCDs provide a signal to noise ratio (SNR) advantage by the ability to measure many wavelengths simultaneously—a multiplex advantage. Consider the SNR for a photomultiplier tube (PMT), a diode array (DA), and a CCD. Assume the readout noise (RN) associated with these devices is 0 photoelectrons (pe^-) for the PMT, 1000 pe^- for the DA and 10 pe­^‑ for the CCD. The readout noise is a constant number that does not change with exposure time, and it adds to other types of noise in the measurement. Assume the only other source of noise in these detectors is shot noise from the signal we are measuring.

When we consider both shot and readout noise, the SNR for a signal S(pe^‑) is given by,

SNR = S/(sqrt[S + (RN)²]).

Assume we want to measure a luminescence signal using a spectrometer that collects a signal of 10⁵ pe^-/s at the detector at every wavelength (e.g., ignore quantum efficiency differences in the detectors, which by the way are in reality very large).

1. What is the signal to noise ratio for a PMT measurement of this luminescence, at a single wavelength, for a 1 second exposure? For a 100 s exposure?
2. How long will it take to measure 1024 wavelengths using the PMT, to give a SNR of 300 at each wavelength?
3. For a 1024-pixel diode array and a 1024x1024 pixel CCD, what total exposure time would be needed to give a SNR of 300 at each wavelength? Note: the readout noise is different for these detectors.
4. Unlike the diode array, the CCD also has pixels in the vertical direction. This gives an additional SNR advantage for the CCD detector. Explain why this is?

The intravenous infusion of fructose into healthy volunteers leads to a two- to fivefold increase in the level of lactate in the blood, a far greater increase than that observed after the infusion of the same amount of glucose. (a) Why is glycolysis more rapid after the infusion of fructose? (b) Based on your answer to question (a), why is the use of fructose in place of glucose for intravenous feeding unwise?

Why are two phosphate groups added to glucose in stage one of glycolysis?

A) To destabilize the intermediates in stage one, making the stage two reactions more favorable.

B) To provide all of the phosphate for ATP synthesis during stage two.

C) To increase the net ATP produced from one glucose molecule.

D) To activate the enzymes in stage two.

Explain please!

1) How many molecules of carbon dioxide are produced per glucose during the citric acid cycle?

2) How many molecules of FADH2 are produced per acetyl CoA during the citric acid cycle?

3) How many molecules of ATP (net) are produced via substrate-level phosphorylation per glucose during glycolysis?

This question is about the pentose phosphate pathway and interconnected metabolic pathways (glycolysis, gluconeogenesis.)

a) What reactions would occur if the cell needed lots of NADPH and only NADPH?

b) What reactions would occur if both NADPH and ATP were both needed?

c) What reactions would occur if nucleotides were needed for DNA synthesis and that was the primary need?