Class Notes

Excretion: Biology Class-note

Excretion is the process by which waste products and excess materials are removed from an organism’s body. These waste products can be in the form of toxic substances, excess ions, and metabolic by-products, and their removal is necessary to maintain homeostasis and prevent damage to the organism. In this class note, we will discuss the different types of excretory structures and excretory mechanisms found in various organisms.



Types of Excretory Structures:

Contractile Vacuole: Found in single-celled organisms, the contractile vacuole is a spherical structure that helps regulate the water balance of the cell. It collects excess water and then contracts, expelling the water out of the cell.

Flame Cell: Found in flatworms, the flame cell is a type of excretory structure that helps remove metabolic waste products from the body. The waste is carried away in a network of tubes and then expelled from the organism.

Nephridium: Found in annelids (such as earthworms), the nephridium is a tubular structure that performs the function of excretion. Nephridia remove metabolic waste products from the body and regulate the balance of ions in the organism.



Malpighian Tubules: Found in insects, the Malpighian tubules are structures that help remove metabolic waste products from the body. They are similar to the nephridia in annelids, and they help regulate the water and ion balance in the organism.

Kidney: Found in vertebrates, the kidney is a complex excretory organ that performs a range of functions, including removing metabolic waste products, regulating water balance, and controlling blood pressure.

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Wikipedia



Stoma: Found in plants, stomata are small pores on the surface of leaves that help regulate water balance and exchange gases between the plant and the environment.

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Science Facts

Lenticel: Found in plants, lenticels are small pores on the surface of stems and roots that help exchange gases between the plant and the environment.

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Excretory Mechanisms:

Kidneys: Kidneys are the primary excretory organs in vertebrates and play a crucial role in removing metabolic waste products from the body and regulating water balance.

Lungs: In humans and other vertebrates, the lungs play a role in the excretion of carbon dioxide, a waste product produced during cellular respiration.

Skin: The skin is also involved in excretion, as it helps regulate the body’s water balance and removes waste products in the form of sweat.

what are Excretory products of plants

Plants, like all living organisms, produce waste products as a result of their metabolic processes. Some of the main excretory products in plants are:

Carbon Dioxide: It is produced during photosynthesis and respiration and is released into the air through small openings in the leaves called stomata.

Oxygen: During photosynthesis, plants produce oxygen and release it into the air.

Water: Plants release water as a result of transpiration, which is the process of water movement through the plant and evaporation from the leaves.

Sugars: During photosynthesis, plants produce excess sugars that they do not need for immediate energy. These excess sugars can be stored in the plant or excreted as waste.

Organic Acids: As plants metabolize food, they produce organic acids such as citric acid, which can be excreted as waste.

Hormones: Hormones play a role in regulating growth and development in plants, and excess hormones can be excreted as waste.

Overall, the excretory products of plants play a critical role in the functioning and survival of both the plant and the surrounding ecosystem.

Tannins: These are a type of polyphenolic compound that are produced and stored in various parts of the plant, including the leaves, stems, and fruits. They have many functions, including acting as a defense mechanism against herbivores and pathogens.

Resins: Resins are produced by some trees and are stored in specialized glands. They serve as a defense mechanism against herbivores and insects, and they also have antimicrobial properties.

Gums: Gums are sticky, water-soluble substances produced by plants. They serve a variety of functions, including acting as a sealant to prevent water loss, providing support to plant tissues, and helping to store energy.

Mucilage: Mucilage is a thick, gooey substance produced by some plants. It helps to retain water and provides a supportive structure for the plant.

Alkaloids: Alkaloids are a class of nitrogen-containing compounds that are produced by a number of plant species. They serve as a defense mechanism against herbivores and have medicinal properties.

In conclusion, excretion is a vital process that helps maintain homeostasis and prevent damage to the organism. Different organisms have different excretory structures and mechanisms to remove waste products, but the ultimate goal is the same: to maintain a healthy balance within the organism.

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How to Solve Grammatical Names and Functions in WAEC & NECO

In this article, we are going to learn How to Solve Grammatical Names and Functions in WAEC & NECO in English Languages questions, specifically on Noun Clause and Phrase.

How to Solve Grammatical Names and Functions in WAEC & NECO 2024

First of all, we need to understand difference between CLAUSE and PHRASE.

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The easiest way to identify whether a group of words is a phrase or a clause is to look for both a subject and a verb. If you can find both, then it is a clause. If you can only find either subject or the other, then it is definitely a phrase

CLAUSE

A clause is a group of words that contains a subject and a verb, example of clause:

  • The Train goes to Stanford Bridge Stadium ==> “Train” is the Subject, “Goes” is the Verb
  • My Uncle live in London ==> “Uncle” is the Subject, “Live” is the verb
  • Whose Father won jackpot ==> “Father” is the Subject, “Won” is the verb
  • The last single from Davido succeeded commercially ==> “Davido” is the Subject, “Succeeded” is the verb

However, clause might be Main (independent) Clause or Subordinate (Dependent) Clause,

PHRASE

A phrase is a group of words, but it doesn’t contain a subject and a verb, example of phrase:

  • The Train to Stanford Bridge Stadium
  • My Uncle in London
  • The last single from Davido


WHAT IS A GRAMMATICAL NAME & FUNCTION?

Grammatical name is the name given to a word or group of words depending on its function and structure in a given clause or sentence OR Grammatical name is the name given to a word, phrase or clause depending on its function in a given clause or sentence.

Grammatical function is the syntactic role played by a word, or clause/phrase in the context of a given clause or sentence. Also, In the English Language, the grammatical function of a word, clause/phrase is determined by the location of that word, clause/phrase in a particular sentence.

TYPE OF GRAMMATICAL NAMES & FUNCTIONS

NOUN CLAUSE/PHRASE: A noun clause/phrase or nominal clause/phrase is a dependent or subordinate clause that does the work of a noun in a sentence. It functions as appositive, the subject or the object of a transitive verb, complement of subject, object and preposition.

Examples:

  1. Segun the policeman arrested the criminal
  2. The criminal arrested by Segun the policeman
  3. Joe Biden won the presidential election
  4. The presidential election is won by Joe Biden
  5. Explanation: from example 1 “Segun the policeman”(which is a noun phrase) functions as the subject of the verb, “arrested”,  and in example 2, Segun the policeman functions as the object of the verb, “arrested”.

    Similarly, in example 3, Joe Biden ”(which is a noun) functions as the subject of the verb, “won”,  and in example 4, Joe Biden functions as the object of the verb, “won”.

    Therefore, in determining the grammatical function of a word, clause/phrase one must take note of the position of that word, clause/phrase in a given sentence.

NOUN CLAUSE/PHRASE GRAMMATICAL NAME & FUNCTIONS

A noun clause/phrase functions as the subject of a verb in a given clause/phrase or sentence.

A noun clause/phrase functions as the object of a verb in a given clause/phrase

 A noun clause/phrase functions as a subject complement

How to Solve Grammatical Names and Functions in WAEC & NECO

NOUN CLAUSE/PHRASE & FUNCTIONS
S/N
Sentences from Past Questions
Grammatical Names
Grammatical Functions
Exam Name & Year
2 but when I discovered that I could take care of myself  Noun clause It is the object of the verb “discovered”. WAEC 2019
5 The teacher raised an instant alarm and the neighbours came rushing to the scene. Noun phrase  It is the object of (the verb) “raised” WAEC 2016
8  It took some time before I realized that my role was crucial since the pilfering of such materials was common in all the other classes.  Noun clause  It is the object of the verb ‘realized’ WAEC 2013

How to Solve Grammatical Names and Functions in WAEC & NECO

ADJECTIVAL CLAUSE/PHRASE:

Adjectival clause/phrase are dependent clause/phrase that give information about nouns. They allow you to combine two sentences into one by using relative pronouns (​who, whom, whose, where, when, which, that, ​and ​why​) as connectors

Example

1. WHO ==> My cousin ​ who​ missed the lecture borrowed Faruk’s notes to review. (Qualifies the noun “cousin”)
2. WHOM ==> The ABC candidate ​ whom ​many people admire won by a landslide. (Qualifies the noun “candidate”)
3. WHOSE ==> I admire Professor Aboki, ​ whose ​ books were stolen. (Qualifies the noun “Aboki”)
4. THAT ==> The lady ​that​ I met at the bus stop today works at GTBank. (Qualifies the noun “lady”)
5. WHICH ==> My new car, ​ which​ was a gift from my dad after graduation, needs to be serviced. (Qualifies the noun “car”)
6. WHEN ==> July 25, ​ when ​ I left home, was great for me. (Qualifies the noun “July 25”)
7. WHERE ==>  I have always wanted to visit the Stamford Bridge Stadium​ where ​Reece plays football. (Qualifies the noun “stadium”)

Take note that an adjectival clause/phrase is usually close to the noun it describes. Aside from taking note of its markers, this is another method one can easily identify an adjectival clause/phrase.

ADJECTIVAL CLAUSE/PHRASE & FUNCTIONS
S/N
Sentences from Past Questions
Grammatical Names
Grammatical Functions
Exam Name & Year
1 Mama chatted heartily with a fellow passenger who was also going to see her son in Lagos Adjectival clause or relative clause  It qualifies the noun “passenger” WAEC 2020
3 Everybody was impressed with the feats which went along with the hilarious drumming

Relative/adjectival clause It qualifies/modifies (the noun) “feats”.

WAEC 2018

10 Left in the lurch, he clung on to a classmate who had longed to work in the city as a petty clerk.  Adjectival/ Relative clause  It qualifies (the noun) “classmate WAEC 2011
11 This is the usual lot of mental patients whose family members refuse to take advantage of orthodox treatment.  Adjectival/Relative clause   It qualifies (the noun) “patients WAEC 2010


ADVERBIAL CLAUSE/PHRASE

An adverb clause is a group of words that is used to change or qualify the meaning of an adjective, a verb, a clause, another adverb, or any other type of word or phrase with the exception of determiners and adjectives that directly modify nouns.

An adverbial clause, sometimes referred to as an adverb clause, is a group of words that, together, functions as an adverb. This means that the clause describes or modifies a verb, adjective, or another adverb.

There are different types of adverbial clause/phrase: adverbial clause of time, place, manner, reason,  condition, concession, etc

Examples

1. It was raining heavily when I woke up.

“When I woke up” is an adverbial clause of time.

Grammatical function: It modifies the verb phrase, “was raining”.

2. Jimmy died because she was stabbed with a broken bottle.

“Because she was stabbed” is an adverbial clause of reason.

Function: It modifies the verb, “died”.

3. The event occurred where three paths meet.

“Where three paths meet” is an adverbial clause of place.

Function: It modifies the verb, “occurred”.

4. Shade sang as if she was hungry.

“As if she was hungry” is an adverbial clause of manner.

Function: It modifies the verb “sang”.

5. I will never leave you unless you kiss me.

“Unless you kiss me” is an adverbial clause of condition.

Function: It modifies the verb phrase, “will never leave”.

ADVERBIAL CLAUSE/PHRASE & FUNCTION

S/N

Sentences from Past Questions

Grammatical Names

Grammatical Functions

Exam Name & Year

 

4

As he dragged it to the surface, we screamed in sudden terror

Adverbial clause (of time)

It modifies/qualifies (the verb) “screamed”

WAEC 2017

 
 

6

Not long after the governor’s official proclamation, newspaper reporters had a field day speculating on the unprecedented confrontation with Chief. 

 It is an adverbial phrase (of time)

It modifies (the verb) ‘had’. 

WAEC 2015

 

7

 while I was watching a 9 0′ clock television network programme, I saw David being interviewed by a team of reporters.

 It is an adverbial clause (of time).

It modifies (the verb) “saw”

WAEC 2014

 
 
 

9

As soon as the chit-chat ended,  they announced that the Ireti ruling council had decided to confer on him the highest traditional title of the land and that a date had been set for the great event.

Adverbial clause (of time)

It modifies (the verb) ‘announced’.

WAEC 2012

 

By the time you finish reading this article, should be able to know How to Solve Grammatical Names and Functions in WAEC & NECO without mush hassle.


 


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Basic Economic Problems: Class Note

Subject

Economics

Topic

Basic Economics Problem

Level

The basic economic problems are the fundamental economic problem such as the issue of scarcity and how best to produce and distribute these scarce resources. As a result of scarcity, choices have to be made, The scale of preference helps in making sensible financial decisions and opportunity cost is the expense of foregoing the next best option while making a decision. A broader explanation of each economic problem will be discussed below.

SCARCITY

People do not have as much as they desire due to economic scarcity. The problem of scarcity emerges because the productive resources available in any society are restricted at any given time, yet human wants are limitless. As a result, the number of commodities and services that may be produced is restricted and insufficient to satisfy human needs.

One of the most important notions in economics is scarcity. It signifies that the demand for a product or service exceeds the supply of that product or service. As a result, scarcity might limit the options available to customers, who make up the economy in the end.

Every society is confronted with the economic dilemma of maximizing the use of limited, or scarce, resources. The economic problem exists because, while people’s needs and desires are limitless, the resources available to meet those needs and desires are finite.

As a result, every society must address four key economic issues.

WHAT TO PRODUCE?

Every society must decide in some way what goods and services to create and how much of each within any particular time period.

 HOW TO BE PRODUCED?

Each firm must decide how to utilize the inputs to achieve optimal resources allocation i.e. the manner of combination of factors of production in order to produce the maximum output quantum of goods and services possible.

FOR WHOM TO PRODUCE? That is, for which category of consumers are the goods being produced? Is it for the young, the old, or for both categories?

HOW TO FACILITATE FUTURE GROWTH?

The resources must be used at a rate that increases future production potential. The most fundamental economic problem that every civilization faces is scarcity. Goods and services would not be scarce if resources were not scarce, and there would be no need to save. As a result, studying economics would be unnecessary.

CHOICE

Choice refers to a consumer’s or producer’s ability to choose from a variety of goods, services, or resources to purchase or give. The ability to make one’s own decisions is viewed as a key sign of economic growth and progress.

As a result of scarcity, choices have to be made. Making a choice entails sacrificing something in order to obtain something else. 

SCALE OF PREFERENCE

A scale of preference is a collection of unfulfilled desires ranked according to their relative importance.  In other words, it’s a list of the ways we wish to satisfy our desires, arranged in priority order.

Moreover, It is defined as a list of all desires to be fulfilled, sorted in priority or importance order. The idea of the Scale of Preference underpins economics’ fundamental assumption that every economic agent acts rationally when making a decision.

For example, if Adams has N10,000 and he has to buy these items. He’ll have to go for the first three on the list. Later on, when he has more cash, he can go for the last two.

ITEMS TO BUY

PRICES (N)

A pair of Snickers

6,500

Chelsea Jersey Shirt

2,500

Perfume

1,000

Bluetooth Earpiece

5,000

Mobile Phone Internet Subscription

3,000

 

The scale of preference helps in making sensible financial decisions that, to some extent, maximize your satisfaction because you will be able to meet all of your immediate demands.

Basic Economic Problems

OPPORTUNITY COST

“In microeconomic theory, the opportunity cost of a particular activity option is the loss of value or benefit that would be incurred by engaging in that activity, relative to engaging in an alternative activity offering a higher return in value or benefit.”

The phrase “opportunity cost” was used by economists to describe the expense of foregoing the next best option while making a decision. The opportunity cost of a commodity purchased is the next most desirable commodity a buyer could have purchased instead. Mr. Adams, for example, wants 1kg of Mackerel fish and 1kg of chicken wings, both of which cost N1500. But, with only N1500 in his pocket, he opted to buy 1kg of Mackerel fish. The opportunity cost of 1kg of mackerel fish bought is a kg of chicken wings forgone.

“The concept of opportunity cost is central to the study of economics because it guides the individual, the firm, and the government to make rational decision on the use of scarce resources.  Opportunity cost is alternatively referred to as real cost or economic cost.”

It’s worth noting that the accountant’s perspective on cost (i.e. accounting cost) differs significantly from the economist’s perspective on cost (i.e. opportunity cost). The cost of a commodity purchased by a consumer or a factor of production purchased by a firm, according to accountants, is the amount of money spent for that commodity or productive resources. This is referred to as the “money cost” or “accounting expense.”

PRODUCTION POSSIBILITIES CURVE (PPC)

The Production Possibilities Curve (PPC) is a model that depicts the tradeoffs that occur when resources are allocated between the production of two goods. Scarcity, opportunity cost, efficiency, inefficiency, economic growth, and contractions can all be illustrated using the PPC.

PPC shows the various combinations of two goods that can be produced when all available resources are fully and efficiently utilized.

Product Combination

Groundnut (bags)

Noodle (cartons)

Opportunity Cost of an extra bag of Groundnut

A

0

200

0

B

1

170

-30

C

2

140

-40

D

3

90

-50

E

4

70

-60

F

5

0

-70

Table 1: PPC schedule

The Production Possibilities Curve (PPC) is a model that captures scarcity and the opportunity costs of choices when faced with the possibility of producing two goods or services. PPC schedule is depicted above in Table 1, The PPC in table 1 is drawn under the assumption that the society is using all its resources to produce only two goods – Groundnut and Noodles.

                                          Basic Economic Problems: Production Possibilities Curve

                                                      Production Possibilities Curve

Key terms under PPC

Efficiency: The PPC will always have full utilization of resources in production; efficient output combinations will always be on the PPC. Point on the PPC (from A to F) represents the many combinations of the two items that the economy can create if all available resources are completely exploited.

Inefficiency: Underutilization of any of the four economic resources (land, labor, capital, and entrepreneurial aptitude); inefficient production combinations are depicted as dots on the PPC’s interior. Any point inside the PPC, such as G, shows that some resources are either left completely idle or are not efficiently utilized.

Scarcity: The curve connecting points A and F forms a boundary that demonstrates that the country’s ability to produce bean and noodles at any given time is limited.

Economic Growth: a gradual improvement in an economy’s ability to create products and services; in the PPC model, economic growth is represented by a shift out of the PPC.

                                              Economy Growth

                                                   PPC demonstration of Economic Growth 

It is described as a steady expansion in an economy’s production capacity, resulting in increased output of products and services. An outward movement in the production possibilities curve from PPC 1 to PPC2 represents this.

Basic Economic Problems: Class Note Read More »

What is Sentence? Structure and Types

What is Sentence? Structure and Types.

In this class note, we are going thoroughly examine what is meant by sentence, it structure and types.

According to Oxford Dictionary, Sentence is “a set of words that is complete in itself, typically containing a subject and predicate, conveying a statement, question, exclamation, or command, and consisting of a main clause and sometimes one or more subordinate clauses.” Also, A sentence is a grammatically complete idea. All sentences have a noun or pronoun component called the subject, and a verb part called the predicate.

Sentence can be SIMPLE, COMPOUND or COMPLEX sentences, each of these will discuss in details one after the other.

SIMPLE SENTENCE

A simple sentence presents a complete notion as an independent clause and has a subject (a person or thing performing an activity) and a predicate (a verb or verbal phrase that defines the action).

Furthermore, a simple sentence has the most fundamental elements of a sentence: a subject, a verb, and a full thought.

Example of Simple Sentences are as follow:

Dele waited for the school bus.
“Dele” = subject, “waited” => verb

The staff bus was late.
“The staff bus” is a noun phrase and the subject of the sentence, “was” = verb

Chioma and Musa travelled by air.
“Chioma and Musa” = compound subject, “travelled” = verb

I searched for Shina and Sade at the cinema hall.
“I” is a pronoun and the subject of the sentence, “searched” = verb

The ladies arrived at the stadium early but waited until noon for the football march to start.
“The ladies” noun phrase the subject of the sentence, “arrived” and “waited” = compound verb

The train leaves every morning at 18 AM.
“The train” is a noun phrase the subject of the sentence, “leaves” => verb or predicate

Water freezes at 0°C
“Water”=> subject, “freezes”=> verb or predicate


They don’t go to school tomorrow
“They” is a pronoun and the subject of the sentence, and “go” is the verb or predicate

The use of compound subjects such Chioma and Musa, compound verb such as “arrived” and “waited”, prepositional phrases (such as “at the stadium”), aid lengthen simple sentences. Also, A simple sentence can be called independent clause. It’s called “independent” because, while it can be used as part of a compound or complex sentence, it can also stand alone as a whole sentence.

COMPOUND SENTENCE

A compound sentence refers to a sentence made up of two independent clauses that are linked together by a coordinating conjunction.

Coordinating conjunction such as:

  • For
  • And
  • Nor
  • But
  • Or
  • Yet
  • So

Example of Compound Sentences are as follow:

I want to lose weight, yet I eat chocolate daily.

A man may die, nations may rise and fall, but an idea lives on.

I used to be snow white, but I drifted.

We went to the mall; however, we only went window-shopping.

She is famous, yet she is very humble.
Mary doesn’t like cartoons because they are loud, so she doesn’t watch them.

They wanted to go to Paris, but I wanted to see London.

She is very smart, and she know
Mary was out of milk, so she went to the store.

COMPLEX SENTENCE

A complex sentence is a sentence with one independent clause and at least one dependent clause.

Complex sentences are simple to recognize because they frequently contain subordinating conjunctions to connect clauses, such as because, since, or until.

Complex sentences are one of the types of sentences based on structure: simple, compound,complex, and compound-complex respectively.

Example of Complex  Sentences are as follow:

Although my friends begged me, I chose not to go to the reunion.

I learned English perfectly because I studied very hard.

Many people enjoyed the movie; however, Alex did not.

Although the farmer is ready, the ground is still too wet to plow.

If the ozone layer collapses, the global community will suffer.

Although I’m not very good, I really enjoy playing football.

Because he did not know the route well, he drove slowly.

Walking through the wood, he saw a fox that was following him.

Dependent clauses, also known as subordinate clauses, are parts of a sentence that cannot stand alone. A dependent clause is nothing more than a sentence fragment without an independent clause.

Example: whose father bought a Bugatti

Independent Clause also called the main clauses is a group of words made up of a subject and a predicate that together express a complete concept.

Example: That is the boy whose father bought a Bugatti

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