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noname [10]
2 years ago
13

Which of the following is a quality of building ledges and roofs in urban environments that lead birds to nest there?

Biology
1 answer:
vichka [17]2 years ago
7 0

Answer: no clue

Explanation: yeah

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What are the main parts that make up the endocrine system and what are their function
Anna11 [10]
Main parts and their functions :

- Hypothalamus : Links the nervous system to the endocrine system via the pituitary gland. It controls the release of 8 hormones by the pituitary gland, controls body temperature, control of food and water intake, hunger and thirst!

- Pituitary gland : Produces essential hormones for everything living such as the growth hormone, adrenocorticotropic hormone, thyroid stimulating hormone, luteinizing hormone and follicle stimulating hormone, etc.

- Thyroid gland : Produces thyroid hormones that regulate the body metabolism, play an important role in bone growth and development of the brain and nervous system in children!

- Parathyroid glands : Release parathyroid hormone which plays a role in regulating calcium levels in the blood and bone metabolism.

- Adrenal glande : Produce hormones that help the body control blood sugar, burn protein and fat, react to stressors, and regular blood pressure.

- Pineal body/gland : Secretes the melatonin hormone which may help regulate the wake-sleep cycle of the body.

- Reproductive glands : Main source of sex hormones for males and females.

- Pancreas : Has digestive and hormonal functions. One part of the pancreas called the exocrine, secures digestive enzymes. While the other part of the pancreas called the endocrine, secretes hormones called insulin and glucagon. Overall, these hormones regulate the level of glucose in the blood.

Hope this helps :)





7 0
3 years ago
2. List three sources of error that could account for the differences between your values for the enthalpy of fusion of water an
Dvinal [7]

1 trial :  nothing is given for result comparision - so we have no idea if it's a mistake.

2nd trial : The results can be compared - if varies, one may go wrong, but which one?

3rd trial : If 3rd result is different from 1st and 2nd, it is unreliable.

calculating enthalpy of fusion. M, C and m,c = mass and specific heat of calorimeter and water, n, L = mass and heat of fusion of ice; T = temperature fall.

L = (mc+MC)T/n.

c=4.18 J/gK. assuming copper calorimeter , so C=0.385 J/gK.

1. M = 409g, m = 45g. T = 22c, n = 14g

L = (45*4.18+409*0.385)*22/14 = 543.0 J/g.

2. M = 409g, m = 49g, T = 20c, n = 13g

L = (49*4.18+409*0.385)*20/13 = 557.4 J/g.

3. M = 409g, m = 54g, T = 20c, n = 14g

L = (54*4.18+409*0.385)*20/14 = 547.4 J/g.

(i) Estimate error in L from spread of 3 results.

Average L = 549.3 J/g.

squared differences average (variance) = (6.236^2+8.095^2+1.859^2)/3 = 35.96

standard deviation = 5.9964

standard error = SD/(N-1) = 5.9964/2 = 3 J/g approx.

% error = 3/547 x 100% = 0.5%.

(ii) Estimate error in L from accuracy of measurements:

error in masses = +/-0.5g

error in T = +/-0.5c

For Trial 3

M = 409g, error = 0.5g

m = 463-409, error = sqrt(0.5^2+0.5^2) = 0.5*sqrt(2)

n =(516-463)-(448-409)=14, error = 0.5*sqrt(4) = 1.0g

K = (mc+MC)=383, error = sqrt[2*(0.5*4.18)^2+(0.5*0.385)^2] = 2.962

L = K*T/n

% errors are

K: 3/383 x 100% = 0.77

T: 0.5/20 x 100% = 2.5

n: 1.0/14 x 100% = 7.14

% errors in K and T are << error in n, so ignore them.

% error in L = same as in n = 7% x 547.4 = 40

The result is (i) L= 549 +/- 3 J/g or (ii) L = 550 +/- 40 J/g.

Both are very far above  334 J/g, so there is at least one systematic error  

e.g: calorimeter may not be copper, so C is not 0.385 J/gK. (If it was polystyrene, which absorbs/ transmits little heat, the effective value of C would be very low, reducing L.)

Using +/- 40 is best.

However, the spread in the actual results is much smaller

* measurements were "fiddled" to get better results; other Trials were made but only best 3 were chosen.

<h3>Other sources of error: </h3>

L=(mc+MC)T/n is too high, so n (ice melted) may be too small, or T (temp fall) too high - why?

* we have assumed initial and final temperature of ice was 0c, it may actually have been colder, so less ice would melt -which explain small values of n

* some water might have been left in container when unmelted ice was weighed (eg clinging to ice) - again this could explain small n;

* poor insulation - heat gained from surroundings, melting more ice, increasing n - but this would reduce measured L below 334 J/g not increase it.

* calorimeter still cold from last trial when next one started, not given time to reach same temperature as water - this would reduce n.

3 0
3 years ago
Use what you know about atmospheric circulation and seasonal changes in the sun’s orientation to earth to explain the highly sea
viva [34]

Answer:

The Inter-Tropical Convergence Zone (ITCZ)region gets the most direct sunlight at any given period in time. This in turn causes air to be unstable with a drop in pressure and rise of air which cools and condenses into clouds to form precipitation causing the wet season in the tropics.

In this region, the sun is directly or almost overhead as seen during summer periods in the tropics.

Only in areas of the North and South of the ITCZ known as doldrums which at times are parallel to the ITCZ do we have high pressure that aren't conducive to precipitation causing dry season in the tropics.

In the ITCZ zone, we also have the tropical rain forests along the equator with huge amount of all round rain for the year.

Along the equator, on either side of the rain forests we have the dry and wet forests with the savannah to the North of this region and the southern hemisphere to the south of these forests since these forests are seen mostly in the ITCZ than the savannahs.

Rain shadows and ocean cueeebts may at times cause some savannahs to be along the equator and some rain forests -wet and dry forests- to be positioned further form the equator.

4 0
3 years ago
Please help please help NO LINKS​
Setler [38]

Answer:

<em>The tyres of car wear out gradually, due to the frictional force. Frictional force arises between two objects when they move over one another. In the given cases it arises between the tyre and the surface which it is travelling on.</em>

6 0
2 years ago
On the average, most mammals are about: A. 90 B. 50 C. 40 D. 70, percent water
andrew11 [14]
D.) 70% mammals are 70 percent water
7 0
3 years ago
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