Correct Answer: B. The levels of energy flow within an ecosystem

Explanation

3 Adeyemi Alao Street

Okeira, Aguda Titun

Lagos 7th August, 1992 Dear uncle,

I know that you must have been wondering why you have not read from me recently. I am indeed very sorry for my failure to write to you since I changed from Abeokuta Community High School to Okeira Grammar School six weeks ago. I am just settling down in my new school.

I know that you may be thinking about what could have led me to change my school. Uncle the reasons are not far fetched. As you know that I am a science student and that the science syllabus is very wide. I need a school where there are enough teachers teaching these science subjects and a school which has got a track record of laudable achievements in science. In my former school, however, the teachers handling these subjects are inexperienced and incompetent, going by my estimation and rating.

Furthermore, my former school lacks good laboratories and a library. Imagine a school with only one laboratory being used for all the three main science subjects. To make the matter worse, this laboratory was not equipped and whenever we were going to have our practical lessons, we usually go to the neighboring school for them.

However, since my resumption in the new school, I always have the feeling that I have got to a school of my choice. There are lots of interesting things about my new school but I will mention only three of them One of them is the availability of competent and qualified teachers. There are enough science teachers and two for each of the science subjects, one teacher handles the practicals while the other handles the theoretical aspect. The methods of teaching by these teachers, to say the least, are fantastic. Other subjects are also handled by hardworking and dedicated teachers. Regular assignments are given to us after every lesson.

Secondly. my new school has reliable laboratories and a big functioning library with relevant and up-to-date text-books. Any science student has access to the equipment in the laboratories and we are free to borrow books from the library.

Thirdly, the school environment is conducive to learning The classrooms are very spacious with ceiling fans and other facilities meant to make students comfortable There is a football field good toilets for students and a big assembly hall with public address systems.

Uncle, I know that you will now understand why I had to change my school. How are your business and family? I hope that things are going on very well Extend my greetings to your children and wife.

Yours sincerely,

Dele.

Correct Answer: C. prevent rotting of fruits

Correct Answer: A) 0.25g

Explanation

To answer this question, we need to find the mass percentage of copper in copper (II) sulphate and then use that percentage to calculate the mass of copper in 1 gram of copper (II) sulphate.

First, let's determine the molecular formula of copper (II) sulphate. It is given by the formula CuSO₄, which consists of one copper (Cu), one sulphur (S), and four oxygen (O) atoms.

Next, let's calculate the molar mass of copper (II) sulphate. Using the provided atomic masses, we have:

\(Molar\,mass\,of\,CuSO_4 = Cu + S + 4O = 40 + 32 + 4(16) = 40 + 32 + 64 = 136\,g/mol\)

Now, we can calculate the mass percentage of copper in copper (II) sulphate:

\(Mass\,percentage\,of\,Cu = \frac{Mass\,of\,Cu}{Molar\,mass\,of\,CuSO_4} \times 100 = \frac{40}{136} \times 100 = 29.41\%\)

Finally, let's find the mass of copper in 1 gram of copper (II) sulphate:

\(Mass\,of\,Cu = Mass\,percentage\,of\,Cu \times Mass\,of\,CuSO_4 = 0.2941 \times 1 = 0.2941\,g\)

Since the closest option to our calculated value is 0.25g (Option A), that is the correct answer.

Correct Answer: B. 1.0 moles

Correct Answer: C) parasitism

Explanation

This question is asking which of the associations results in much harm to one of the partners. The options are symbiosis, commensalism, parasitism, and mutualism. Symbiosis refers to a close relationship between two different species where both partners benefit. Commensalism refers to a relationship where one partner benefits, and the other partner is neither helped nor harmed. Mutualism refers to a relationship where both partners benefit. On the other hand, parasitism is a relationship where one partner (the parasite) benefits while the other partner (the host) is harmed. The parasite feeds on the host and negatively affects its health. Therefore, the correct option is C: parasitism. Parasites can cause diseases in their hosts, which can lead to severe harm or even death. Examples of parasites include tapeworms, fleas, lice, and ticks. It is essential to take measures to prevent parasitic infections by avoiding contact with infected individuals, maintaining personal hygiene, and using insect repellents. In conclusion, parasitism is an association where one partner benefits at the expense of the other partner, resulting in much harm to the latter.

Correct Answer: B. an entrepreneur

Explanation

(a) A commercial bank is a financial institution, usually established as a joint-stock company with the aim of making profit. It usually grants short-term and medium

term loans.

(b) The various ways by which the central bank controls the amount of credit given by the commercial banks are:

(i)Through the manipulation of the Bank Rate:If the central bank wants to encourage the commercial banks to lend more it would reduce the Bank Rate. If it wants to

discourage the commercial banks from lending it would raise the Bank Rate

(ii)Open Market Operations: The central bank sells securities on the open market to reduce the reserves of the commercial banks and so limit their ability to lend. On the other hand if it wants to encourage the commercial banks to lend, it buys securities on the open market to Increase the cash reserves of the commercial banks.

(iii) Special deposits: By calling on the commercial banks to make special deposits With it, the central bank reduces the reserves the commercial banks are free to use to give credit.

(iv)Through the manipulation of the cash minimum reserve ratio/liquidity ratio: The cash ratio is raised when it is desired to discourage lending by the commercial banks. On the other hand it is reduced when it is desired to encourage them to lend

(v)Directives/Selective credit control: The central bank has authority to give direct instructions to the commercial banks as to whether or not they should increase their lending. Sometimes it gives directives as to sectors of the economy that should be favored in granting loans.

(vi)Moral suasion: Sometimes by merely announcing to the commercial banks its policy on lending, the central bank succeeds in getting the commercial banks to behave as expected

(vii)Funding: The central bank can convert short- term securities into long-term securities and so prevent an increase in the reserves of the commercial banks.

Correct Answer: C. Four

Explanation

Ways in which Commerce is important in life of a nation:

(i) Commerce promotes rapid transfer of both oral and written messages through communication.

(ii) Commerce facilitates exchange of goods and services which people all over the nation enjoy produced within or outside their own nation.

(iii) Commerce creates revenue/wealth for the nation through collection of tariff duties royalties and tourism.

(iv) Commerce makes for the protection against risk in the day-to-day business operations through insurance.

(v) Commerce creates awareness of the existence of goods and services through advertising.

(vi) Commerce ensures that goods and produced are stored until needed, thus making sure that there is steady supply of goods for the nation through warehousing.

(vii) Commerce offers employment to a large number of people in a nation such as traders, retailers, wholesalers, bankers brokers.

(viii) Commerce provides money and banking facilities through creation of means of payment, loans and advances.

(ix) Commerce assist in movement of people, materials and finished goods from production point to consumption point.

(x) Commerce encourages cooperate and friendliness among nations.

(xi) Commerce improves peoples standard of living through provision of varieties of goods and services.