WAEC SSCE - Biology - 2011 (Objective)

Question 1 Report

What will be the chromosome number of the hybrid of two varieties of a plant with 36 chromosomes in the endosperm cell?

12

24

35

48

Chromosomes: The Basis Of Heredity

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Question 2 Report

Which of the following groups of substances are not six-carbon compounds?

Glucose and lactose

Lactose and cellulose

Glucose, Lactose and Pyruvate

Pyruvate and cellulose

Answer Details

The correct answer is "Pyruvate and cellulose" because both pyruvate and cellulose are not six-carbon compounds. Pyruvate is a three-carbon compound produced during glycolysis, while cellulose is a polymer made up of repeating glucose units and has a much larger molecular weight than glucose. The other options contain at least one six-carbon compound: glucose has six carbons, lactose is made up of glucose and galactose (both six-carbon compounds), and cellulose contains repeating glucose units.

Read lesson note on Nutrition (JAMB)

Nutrition

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Question 3 Report

Which of the following cells are not regarded as specialized?

Sperm cells

Root up cells

Muscle cells

somatic cells

Answer Details

Somatic cells are not regarded as specialized cells. Somatic cells are the body cells that make up most of the body tissues and organs. They perform general functions in the body such as providing structural support, protection, and nutrient transport. In contrast, specialized cells have specific functions and characteristics that allow them to perform specific tasks. For example, sperm cells are specialized cells that are involved in reproduction, muscle cells are specialized cells that are involved in movement, and root hair cells are specialized cells that are involved in nutrient uptake.

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Question 4 Report

Which of the following methods is appropriate for the cultivation of cassava?

Budding

Fragmentation

Root cutting

Stem cutting

Answer Details

The appropriate method for the cultivation of cassava is stem cutting. This involves cutting stems of cassava plants into sections, usually 20-30 cm long, and planting them in soil. The stems will sprout and grow into new cassava plants. This method is commonly used because cassava does not produce true seeds and cannot be propagated through budding or fragmentation. Root cutting can be used, but it is less efficient than stem cutting because it takes longer for the roots to develop into new plants.

Read lesson note on Humans And Environment (JAMB)

Read lesson note on The Ecology Of Populations (JAMB)

Humans And Environment

The Ecology Of Populations

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Question 5 Report

Differences in characteristics observed between individuals of the same species is known as

trait

phenotype

mutation

variation

Answer Details

The term used to describe differences in characteristics observed between individuals of the same species is "variation". Variation can be caused by a number of factors, including genetic differences, environmental factors, and interactions between genes and the environment. Variation can be observed in many different traits or characteristics, such as height, weight, color, behavior, and more. Understanding and studying variation is important in fields such as genetics, ecology, and evolution, as it can help us to understand how and why populations change over time.

Read lesson note on Behavioural Adaptations In Social Animals (WAEC)

Read lesson note on Heredity (JAMB)

Behavioural Adaptations In Social Animals

Heredity

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Question 6 Report

Use the information on capture-recapture method to calculate the total number of organisms in a habitat.
First capture = 200
Second capture = 120
Number of organisms with mark in second capture = 40

The total number of organisms therefore is

200

360

600

800

Answer Details

The capture-recapture method is used to estimate the total population size of a species in a given area. The formula for this method is: Total population size = (number marked in first sample * number in second sample) / number marked in second sample Using the values given in the question: Number marked in first sample = 200 Number in second sample = 120 Number marked in second sample = 40 Plugging in these values into the formula, we get: Total population size = (200 * 120) / 40 = 600 Therefore, the total number of organisms in the habitat is 600. So the answer is option C - 600.

Read lesson note on Nutrition (JAMB)

Read lesson note on Support And Movement (JAMB)

Nutrition

Support And Movement

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Question 7 Report

Which of the following activities promotes forest conservation?

Lumbering

Use of firewood for cooking

Afforestation

Production of paper

Answer Details

Afforestation is an activity that promotes forest conservation. Afforestation involves the planting of new trees in areas where there was no forest before. This activity helps to increase the forest cover, which provides a habitat for many species of animals and plants, helps to reduce soil erosion, and prevents flooding. Additionally, afforestation helps to combat climate change by absorbing carbon dioxide from the atmosphere. Therefore, afforestation is an important activity that promotes the conservation of forests. The other options listed in the question, such as lumbering, use of firewood for cooking, and production of paper, can contribute to deforestation and degradation of forests.

Read lesson note on Resources To Be Conserved: Soil, Water, Wildlife, Forest And Minerals (WAEC)

Read lesson note on Ways Of Ensuring Conservation (WAEC)

Resources To Be Conserved: Soil, Water, Wildlife, Forest And Minerals

Ways Of Ensuring Conservation

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Question 8 Report

Which of the following statements best describes protein synthesis?

DNA is directly involved in translation

translocation oft e ribosomes exposes a new codon for base pairing with an amino acid

Each tRNA with a particular anticodon always carries a different protein in the process

One amino acid is always carried by more than one

Protein Synthesis

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Question 9 Report

The conversion of glucose to starch in the leaf during the day principally

enables photosynthesis

prevents osmotic problems

enables the leaf to store the starch

enables glucose to be used up

Answer Details

During photosynthesis, plants produce glucose as a result of the conversion of carbon dioxide and water using sunlight. This glucose can be used to meet the energy requirements of the plant. However, since the plant can only use so much glucose at once, it needs to store the excess glucose for future use. The conversion of glucose to starch in the leaf during the day primarily enables the leaf to store the excess glucose as starch. Starch is a more compact and stable form of glucose storage, which is easily stored in the plant cells. By converting glucose to starch, the plant can store more glucose in a smaller space and keep it stable for longer periods. Thus, the conversion of glucose to starch in the leaf is an essential process that enables plants to store excess glucose and meet their energy needs efficiently.

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Question 10 Report

Which of the following structures produces the greatest variety of digestive enzymes?

Salivary glands

Pancreas

Stomach

Colon

Answer Details

The structure that produces the greatest variety of digestive enzymes is the pancreas. The pancreas is an organ located behind the stomach and it secretes digestive enzymes that help in the breakdown of carbohydrates, fats, and proteins in the small intestine. The enzymes produced by the pancreas include amylase, lipase, and protease, which can break down carbohydrates, fats, and proteins respectively. The salivary glands produce amylase which helps in the breakdown of carbohydrates in the mouth, while the stomach produces pepsin, which breaks down proteins. The colon, on the other hand, absorbs water and electrolytes, and is not primarily involved in enzyme production. Therefore, the correct answer is the pancreas.

Read lesson note on Alimentary System (WAEC)

Alimentary System

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Question 11 Report

The rate of decomposition of organisms is faster in the tropical rain forest than in other biomes because

of the relatively constant daylight

there are more plants per square feet

of abundance of water

of constant cool temperature

Local (Nigerian) Biomes

Ecosystem

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Question 12 Report

Ecological investigation in a habitat includes the following procedures except

choosing a habitat

identification of specimens

determining the genetic makeup of specimens

measuring abiotic and biotic factors

Answer Details

Ecological investigation in a habitat includes choosing a habitat, identification of specimens, and measuring abiotic and biotic factors. Determining the genetic makeup of specimens is not typically included as part of ecological investigation in a habitat. Genetic makeup is more relevant in genetic research or population genetics, which is a different field of study from ecology. Ecological investigation is focused on the study of the relationships and interactions between living organisms and their environment. This involves examining the physical and chemical factors of the environment, as well as the diversity and distribution of species in the ecosystem.

Read lesson note on Variation In Population (JAMB)

Variation In Population

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Question 13 Report

Secondary growth is brought about by the activities of the

phellogen and phelloderm

phellogen and procambium.

vascular cambium and phelloderm

vascular cambium and phellogen

Answer Details

Secondary growth in plants refers to the increase in the girth or thickness of the plant stem or root. This process is brought about by the activity of the vascular cambium, a lateral meristem responsible for the production of secondary xylem and phloem. The vascular cambium divides actively, producing new cells towards the inner side (secondary xylem) and the outer side (secondary phloem). As a result, the stem or root increases in girth over time. The other options, phellogen and phelloderm, are involved in the formation of the protective outer bark in woody plants.

Read lesson note on Cell Structure (WAEC)

Cell Structure

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Question 14 Report

Which of the following methods does not make water fit for drinking?

Addition of chlorine

Boiling

Distillation

Addition of alum

Resources To Be Conserved: Soil, Water, Wildlife, Forest And Minerals

Nervous Coordination

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Question 15 Report

What is the probability? of a man of blood group AB married to a woman of blood group O producing a child of blood group O?

0%

25%

50%

75%

Application Of The Principles Of Heredity

Heredity

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Question 16 Report

The falling off of leaves of deciduous trees is helpful to the plant because it

reduces the rate of transpiration

enables the plant to conveniently eliminate its excretory products

enables the plant to bear more fruits

ensures that the limited mineral salts get to only growing regions

Answer Details

The falling off of leaves of deciduous trees is helpful to the plant because it reduces the rate of transpiration. Deciduous trees shed their leaves during the dry season to conserve water. The leaves of these trees have stomata that can lose water through transpiration. Shedding of leaves helps reduce the surface area of the plant that can lose water through transpiration, thus conserving water. Additionally, the fallen leaves decompose, adding nutrients to the soil, which are later used by the plant to produce new leaves.

Read lesson note on Plant Nutrition (WAEC)

Read lesson note on Adaptive Colouration (WAEC)

Plant Nutrition

Adaptive Colouration

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Question 17 Report

Natural selection is a consequence of

distribution of organisms

adverse conditions

variation in organisms

inbreeding

Heredity

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Question 18 Report

ore sweat is produced during muscular exercise because

the contracting muscles produce water

fermentation occurs in muscles

the temperature of the body rises

the muscle fatigues

Answer Details

More sweat is produced during muscular exercise because the temperature of the body rises. When muscles contract during exercise, they generate heat which raises the body temperature. To prevent the body from overheating, sweat glands are stimulated to produce sweat. Sweat, which is mostly composed of water and salt, evaporates from the skin surface and removes heat from the body, thus reducing the body temperature. This process is known as evaporative cooling. Therefore, the more a person exercises, the more heat is produced, and the more sweat is produced to cool the body down.

Read lesson note on Regulation Of Internal Environment (WAEC)

Regulation Of Internal Environment

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Question 19 Report

A man with blood group It I^A I^A is married to a woman with blood group I^A I^O. The blood group of their son is likely to be

A

O

B

AB

Answer Details

The man has blood group IA IA, which means that he has two copies of the A allele. The woman has blood group IA IO, which means she has one A allele and one O allele. When they have a child, each parent passes one allele to their child. The possible combinations of alleles that their child can inherit are IA from the father and IA or IO from the mother. So, the child can have blood group IA IA, IA IO, or IO IO. However, the child cannot have blood group B or AB because neither parent has the B allele. Therefore, the likely blood group of their son is A.

Read lesson note on Heredity (JAMB)

Heredity

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Question 20 Report

A xerophyte conserves water by possession of the following features except

thick cuticle

sunken stomata

broad leaves

fleshy stem

Answer Details

A xerophyte is a plant that has adapted to survive in environments with low water availability. To conserve water, xerophytes possess certain features such as a thick cuticle on leaves, sunken stomata to reduce water loss, and a fleshy stem to store water. However, xerophytes do not have broad leaves as this would result in increased transpiration and water loss, which is contrary to their water-conserving adaptation. Therefore, the correct answer is "broad leaves".

Read lesson note on Classification (WAEC)

Classification

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Question 21 Report

Which of the following enzymes is active in the duodenum?

Pepsin

Renin

Trypsin

Amylase

Answer Details

The enzyme that is active in the duodenum is Trypsin. When food leaves the stomach, it enters the duodenum of the small intestine. Trypsin is produced by the pancreas and is released into the duodenum. Its function is to break down proteins into smaller peptides. This process aids in digestion and allows for the absorption of essential amino acids by the body. Therefore, the correct option is Trypsin.

Read lesson note on Protein Synthesis (WAEC)

Protein Synthesis

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Question 22 Report

In which of the following habitats is Paramecium no found

Pond

Aquarium

Lake

Puddle

Amoeba, Paramecium, And Euglena

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Question 23 Report

The process whereby electrons are emitted from chlorophyll and returned to it unchanged is known as?

non-cyclic phosphorylation

photochemical reaction

photophorylation

cyclic photophorylatlion

Answer Details

The process whereby electrons are emitted from chlorophyll and returned to it unchanged is known as cyclic photophosphorylation. During this process, light energy is absorbed by chlorophyll and used to excite electrons, which then move along an electron transport chain and ultimately return to the chlorophyll molecule. This results in the generation of ATP (adenosine triphosphate), which is an important energy source for the cell. Unlike non-cyclic photophosphorylation, which involves the transfer of electrons to an electron acceptor and the subsequent generation of NADPH in addition to ATP, cyclic photophosphorylation only generates ATP.

Read lesson note on Protein Synthesis (WAEC)

Protein Synthesis

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Question 24 Report

Which of the following is an effector organ?

Tongue

Skin

Nose bridge

Ear glands

Answer Details

Effector organs are the organs that carry out the response or action in response to a stimulus. Among the given options, the skin is an effector organ as it responds to stimuli such as heat, cold, pressure, and pain, by activating various physiological mechanisms such as sweating, shivering, and blood vessel constriction or dilation, to maintain the body's internal balance or homeostasis. The tongue, nose bridge, and ear glands are not considered effector organs as they do not have a direct role in carrying out a physiological response to a stimulus.

Read lesson note on Population Studies By Sampling (WAEC)

Population Studies By Sampling

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Question 25 Report

Adenine pairs with thymine because

the two occur in the same nucleic acid

one is a strong base and the other a weak base

two purine bases easily pair up

one is a purine base and the other a pyrimidine.

Answer Details

Adenine pairs with thymine because one is a purine base (adenine) and the other is a pyrimidine base (thymine). The structure of DNA requires that the nitrogenous bases, which make up the "rungs" of the DNA ladder, pair in a specific way: purines (adenine and guanine) must pair with pyrimidines (thymine and cytosine). Adenine has a complementary hydrogen-bonding pattern with thymine, which allows them to pair together, forming two hydrogen bonds between them. This specific pairing between the bases is important for DNA replication and the accurate transmission of genetic information.

Read lesson note on DNA Structure And Replication, RNA Transcription (WAEC)

Read lesson note on Nucleic Acids (WAEC)

DNA Structure And Replication, RNA Transcription

Nucleic Acids

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Question 26 Report

Leguminous crops are incorporated into crop rotation in order to

improve aeration of the soil.

promote nitrogen fixation

increase the rate of soil formation

improve upon the water holding capacity of the soil

Answer Details

Leguminous crops are incorporated into crop rotation in order to promote nitrogen fixation. Leguminous plants form a symbiotic relationship with nitrogen-fixing bacteria, Rhizobia, which live in nodules on their roots. These bacteria convert atmospheric nitrogen into a form that plants can use, such as ammonia or nitrates. When leguminous crops are grown and then plowed under the soil, the nitrogen-rich plant material breaks down and releases this essential nutrient into the soil, making it available for other crops to use in subsequent rotations. Therefore, leguminous crops are important in maintaining soil fertility, reducing the need for synthetic fertilizers, and increasing crop yields.

Read lesson note on Resources To Be Conserved: Soil, Water, Wildlife, Forest And Minerals (WAEC)

Read lesson note on Physiological Variations (WAEC)

Resources To Be Conserved: Soil, Water, Wildlife, Forest And Minerals

Physiological Variations

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Question 27 Report

Which of the following practices improves crop yield in a clayey soil? Addition of

more water and humus

lime and humus

fertilizers

weedicides and fertilizers

Answer Details

The practice that improves crop yield in a clayey soil is the addition of lime and humus. Clayey soils are often compact and have low nutrient levels, making it difficult for crops to grow properly. The addition of lime helps to reduce the acidity of the soil, which can be toxic to plants. The addition of humus helps to increase the organic matter content of the soil, which can improve soil structure and nutrient availability. Both lime and humus can help to improve soil fertility, making it easier for crops to grow and produce a higher yield.

Read lesson note on Resources To Be Conserved: Soil, Water, Wildlife, Forest And Minerals (WAEC)

Read lesson note on Food Webs And Trophic Levels (WAEC)

Resources To Be Conserved: Soil, Water, Wildlife, Forest And Minerals

Food Webs And Trophic Levels

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Question 28 Report

Some animals return to water bodies to reproduce because

natural enemies destroy their eggs on land

water nourishes their embryos and their young ones

they are close to their ancestors and imitate them

the temperature on land is not suitable for the development of their embryos

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Question 29 Report

The removal of all the phloem tissues of the stem of a plant close to the root system for a long period of time is likely to

provide more energy to the roots

accumulate more starch in the roots

cause the underground roots to develop buds

cause the p ant to wither and die

Answer Details

Phloem is responsible for the transportation of the products of photosynthesis, including sugar and other nutrients from the leaves to other parts of the plant, including the roots. If all the phloem tissues of the stem of a plant close to the root system are removed for a long period of time, the roots will not receive the necessary nutrients to survive. Without the products of photosynthesis, the roots will not have enough energy to carry out important processes such as respiration and growth. Therefore, the most likely outcome of this scenario is that the plant will wither and eventually die.

Read lesson note on Plant Nutrition (WAEC)

Plant Nutrition

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Question 30 Report

If Amoeba is placed in a salt solution. the contractile vacuoles would

be bursting more frequently

be more numerous

be formed less frequently

grow bigger before they burst

Answer Details

When an amoeba is placed in a salt solution, the salt solution is hypertonic (higher concentration of solute) compared to the cytoplasm of the amoeba. As a result, water from the cytoplasm moves out of the cell through osmosis to the hypertonic salt solution, causing the amoeba to shrink. In response to this, the contractile vacuole in the amoeba would form more frequently to pump out the excess water from the cytoplasm in order to maintain the osmotic balance and prevent the amoeba from bursting. Therefore, the correct option is "be formed less frequently" as the opposite is true.

Read lesson note on Nucleic Acids (WAEC)

Read lesson note on Cell Structure (WAEC)

Nucleic Acids

Cell Structure

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Question 31 Report

Filtrate in the Bowman’s capsule contains vitamins because

only all le amount is required by the body

they can be reabsorbed into the blood

they have low molecular weight

most of them are fat soluble.

Answer Details

Filtrate in the Bowman's capsule contains vitamins because they have a low molecular weight. Vitamins are organic compounds that the body needs in small amounts to maintain normal physiological function. Due to their small size and molecular weight, they can easily pass through the glomerulus and into the Bowman's capsule during filtration in the kidney. Once in the filtrate, vitamins can be reabsorbed into the bloodstream and utilized by the body, or excreted in the urine if they are present in excess. Therefore, the correct option is "they have low molecular weight".

Read lesson note on Classification (WAEC)

Read lesson note on Adaptive Colouration (WAEC)

Classification

Adaptive Colouration

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Question 32 Report

Kreb’s cycle occurs in the

mitochondria

cytoplasm

nucleus

ribosomes

Answer Details

Kreb's cycle, also known as the citric acid cycle or TCA cycle, occurs in the mitochondria. It is a series of chemical reactions that occur in the presence of oxygen and play a critical role in the production of energy in the form of ATP during cellular respiration. The cycle starts with the entry of acetyl-CoA into the cycle, which then undergoes a series of reactions to produce NADH and FADH2, which are important electron carriers. These electron carriers then go on to participate in the electron transport chain, leading to the production of ATP.

Read lesson note on Cellular Respiration (WAEC)

Cellular Respiration

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Question 33 Report

The part labelled II in the diagram is

centriole

chloroplast

chromatid

tonoplast

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Question 34 Report

Which of the following substances when lost from the body of a mammal will not be returned to the ecosystem?

Sweat

Urea

Heat energy

Carbon dioxide

Humans And Environment

Excretory Systems And Mechanisms; Types Of Excretory Systems

Factors Affecting The Distribution Of Organisms

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Question 35 Report

The branch of Biology that deals with the principles of classification of organisms is known as

biological index

nomenclature

taxonomy

ecology

Answer Details

The branch of biology that deals with the principles of classification of organisms is known as taxonomy. Taxonomy is the scientific study of how living things are classified or grouped based on their characteristics and relationships with one another. This involves identifying, naming, and organizing species into hierarchical categories or taxonomic ranks, such as kingdom, phylum, class, order, family, genus, and species. The aim of taxonomy is to provide a systematic and logical framework for the study of biodiversity and the relationships among different organisms.

Read lesson note on Classification (WAEC)

Classification

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Question 36 Report

A sample of wet garden soil of known weigh was heated to constant weight. The loss of weight is due to loss of

water

organic matter

water and organic matter

water and inorganic matter

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Question 37 Report

The testes in male mammals descend into the scrotal sac because

there is congestion in the lower abdomen

they run the risk of being destroyed

they need special support

they require a relatively low temperature

Answer Details

The testes are the male reproductive organs responsible for producing sperm and the male hormone testosterone. In mammals, including humans, the testes initially form inside the abdomen, near the kidneys. However, for the production of healthy sperm, the testes need to be maintained at a temperature lower than the normal body temperature. Hence, during fetal development, a structure called the gubernaculum begins to pull the testes down towards the scrotal sac. As the testes move down, they are accompanied by blood vessels, nerves, and a duct called the vas deferens, which carry sperm from the testes to the urethra. Once the testes reach the scrotal sac, they are positioned outside the body, where the temperature is lower than the body temperature. This helps to keep the testes cool, which is important for the production of healthy sperm. Therefore, the testes in male mammals descend into the scrotal sac to maintain a relatively low temperature that is optimal for the production of healthy sperm.

Read lesson note on Organization Of Life (WAEC)

Read lesson note on Growth (JAMB)

Organization Of Life

Growth

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Question 38 Report

Assuming that a period of stable population size is followed by a period when natality increases by ten (1O) per cent and immigration increases by twenty (20) percent of population size. The population size will

be at equilibrium

increase by forty (40) per cent

begin to increase

begin to decrease

Answer Details

If the population size is stable, it means that the birth rate (natality) and immigration rate are equal to the death rate (mortality) and emigration rate respectively. However, if there is a ten percent increase in natality and a twenty percent increase in immigration, the population size will begin to increase. This is because the number of individuals added to the population through births and immigration will exceed the number lost through deaths and emigration, resulting in a net increase in population size. Therefore, the correct answer is "begin to increase."

Read lesson note on Co-ordination And Control (JAMB)

Co-ordination And Control

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Question 39 Report

Vaccination results in

aiding red blood cells to carry more oxygen

production of antibodies which destroy toxins of germs

arresting excessive bleeding

production of white blood cells which engulf and digest bacteria.

Answer Details

Vaccination results in the production of antibodies which destroy toxins of germs. When a vaccine is introduced into the body, it triggers an immune response, causing the immune system to produce specific antibodies against the pathogen. These antibodies circulate in the body and are ready to attack the pathogen if it enters the body. In this way, the body is able to quickly and effectively fight off the pathogen and prevent the development of the disease. This is the primary mechanism by which vaccination protects against infectious diseases.

Read lesson note on Biology And Water Industry (WAEC)

Read lesson note on Nervous Coordination (WAEC)

Read lesson note on The Cell And Its Environment: Physical And Biophysical Processes (WAEC)

Biology And Water Industry

Nervous Coordination

The Cell And Its Environment: Physical And Biophysical Processes

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Question 40 Report

The following processes are involved in water movement in the endodermis except

osmosis

vacuolar pathway

diffusion

active transport

Answer Details

The correct answer is option C: diffusion. Water movement in the endodermis of plant roots is regulated by a specialized cell layer known as the Casparian strip. The Casparian strip prevents water and solutes from moving freely through the cell walls between endodermal cells, forcing them instead to cross the plasma membrane of the endodermal cells. Once inside the endodermal cells, water and solutes can move through two pathways: the apoplastic pathway, which is the space between the cell walls of adjacent cells, and the symplastic pathway, which is the cytoplasmic continuum that links adjacent cells through plasmodesmata. Water moves through the symplastic pathway by osmosis, driven by differences in solute concentration between the soil and the root. Active transport of solutes also plays a role in establishing these concentration gradients. Once inside the root, water and solutes can be transported to the xylem, which carries them to the rest of the plant. The process that is not involved in water movement in the endodermis is diffusion, which is the movement of solutes from an area of high concentration to an area of low concentration. While diffusion can occur in the apoplastic and symplastic pathways, it is not the primary driving force behind water movement through the endodermis.

Read lesson note on Movement Of Substances Into And Out Of Cells (WAEC)

Read lesson note on Energy Transformation In Nature (WAEC)

Read lesson note on Microorganisms Around Us (WAEC)

Read lesson note on Nucleic Acids (WAEC)

Movement Of Substances Into And Out Of Cells

Energy Transformation In Nature

Microorganisms Around Us

Nucleic Acids

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Question 41 Report

Cells that utilise a lot of energy are characterized by the presence of a large number of

vacuoles

mitochondria

endoplasmic reticulum

ribosomes

Answer Details

Cells that utilize a lot of energy require a lot of ATP, the energy currency of cells. Mitochondria are the organelles responsible for producing ATP in cells through cellular respiration. Therefore, cells that use a lot of energy, such as muscle cells or neurons, will have a large number of mitochondria to produce the ATP they require. So, the correct answer is mitochondria.

Read lesson note on Nucleic Acids (WAEC)

Nucleic Acids

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Question 42 Report

Which of the following statements best describes haemoglobin? It is

yellowish in colour

a red blood cell

an oxygen carrying pigment

needed for blood clotting

Answer Details

Haemoglobin is an oxygen-carrying pigment found in the red blood cells of mammals. It is responsible for transporting oxygen from the lungs to other tissues in the body, and it also helps to transport carbon dioxide from the tissues back to the lungs for exhalation. Therefore, the statement that best describes haemoglobin is that it is an oxygen-carrying pigment.

Read lesson note on Nutrition (JAMB)

Nutrition

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Question 43 Report

During sexual reproduction in Paramecium, how many times does the zygote divide to produce eight nuclei?

1

2

3

4

Answer Details

During sexual reproduction in Paramecium, the zygote undergoes meiosis to form four haploid nuclei. These haploid nuclei then undergo two rounds of mitosis to produce eight nuclei. Therefore, the zygote divides three times to produce eight nuclei. The correct answer is 3.

Read lesson note on Chromosomes: The Basis Of Heredity (WAEC)

Chromosomes: The Basis Of Heredity

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Question 44 Report

Which of the following statements is not true about continuous variation? It

is usually controlled by several genes

can be influenced by environmental factors

follows a normal distribution curve

is usually controlled by one or two pair(s) of genes

Answer Details

The statement that is not true about continuous variation is: "is usually controlled by one or two pair(s) of genes". Continuous variation is a type of variation that shows a wide range of possible values for a particular trait, and is usually controlled by several genes, with each gene contributing a small amount to the final phenotype. Continuous variation can also be influenced by environmental factors, such as nutrition or exposure to certain chemicals. The distribution of continuous variation usually follows a normal distribution curve, with most individuals clustering around the mean value and fewer individuals at the extremes of the distribution. Therefore, the statement that is not true is that continuous variation is usually controlled by one or two pair(s) of genes.

Read lesson note on Classification (WAEC)

Read lesson note on Behavioural Adaptations In Social Animals (WAEC)

Read lesson note on Heredity (JAMB)

Classification

Behavioural Adaptations In Social Animals

Heredity

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Question 45 Report

A vestigial structure in humans is

earlobe

toe bone

tail bone

spleen

Answer Details

A vestigial structure in humans is a structure that has lost its original function due to evolution. In other words, it served a purpose in an ancestor of the species, but is no longer necessary or useful in the current form of the species. In humans, the tail bone or coccyx is considered a vestigial structure because it was used for balance and mobility in our primate ancestors, but has no apparent function in humans.

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Question 46 Report

Which of the following structures is a tissue

Vessel element

Blood

Sieve tube element

Erythrocyte

Tissues And Supporting Systems:

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Question 47 Report

If a person has two alleles of the sickle cell anaemia gene, the person

is a heterozygous carrier of the disease

is immune to the disease and cannot pass it on to an offspring

has the disease

is probably of Asian ancestry

Answer Details

If a person has two alleles of the sickle cell anaemia gene, the person has the disease. Sickle cell anaemia is an autosomal recessive genetic disorder, which means that two copies of the abnormal gene are required to have the disease. A person with one abnormal and one normal gene is a carrier and does not have the disease but can pass the abnormal gene to their offspring. A person with two abnormal genes has the disease and may experience symptoms such as pain, fatigue, and anemia.

Read lesson note on Heredity (JAMB)

Heredity

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Question 48 Report

A monocot root IS different from a dicot root by having

endodermis

cambium

wide pith

root hair.

View Answer

Question 49 Report

The part labelled I is called the

nucleolus

centromere

centriole

spindle

Nucleic Acids

Cell Structure

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Question 50 Report

Which of the following components of Larmark’s theory of evolution is considered faulty?

Individuals of the same species growing under different environmental conditions differ from each other

Use of certain organs result in development of those parts

Unused organs degenerate

Changes that result in individuals of the same species are transmitted to offspring

Answer Details

The component of Lamarck's theory of evolution that is considered faulty is "Changes that result in individuals of the same species are transmitted to offspring." This idea, also known as the inheritance of acquired characteristics, suggests that an organism can pass on characteristics it has acquired during its lifetime to its offspring. However, this has been disproven by modern genetics, which shows that inherited traits are determined by an organism's DNA and not influenced by its experiences during life. Therefore, traits acquired during an individual's lifetime cannot be inherited by its offspring.

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Theories Of Evolution

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Question 51 Report

Which of the following pairs of cells carry out the same function?

Check cell and red blood cell

Spermatozoan and ovum

Palisade cell and epidermal cell

Root tip cell and guard cell

Cell Structure

Respiratory System

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Question 52 Report

Which of the following structures is not involve in respiration?

Lung books

Mouth

Stomach

Trachea

Answer Details

The structure that is not involved in respiration is the stomach. Respiration is the process of gas exchange, which involves taking in oxygen and releasing carbon dioxide. The lungs, mouth, and trachea are all involved in respiration. The lungs are the primary organ of respiration where gas exchange occurs. The trachea, also known as the windpipe, is the tube that carries air from the mouth and nose to the lungs. The mouth serves as an opening for air to enter the respiratory system. The stomach, on the other hand, is involved in the digestion of food, which is a separate process from respiration.

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Respiration

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Question 53 Report

A purple colour was obtained when sodium hydroxide solution and a drop of copper sulphate solution were added to a food substance. The food substance is likely to be a

carbohydrate

fat

protein

sugar

Answer Details

The food substance is likely to be a protein. When sodium hydroxide solution and a drop of copper sulphate solution are added to a protein, it forms a violet or purple color. This is due to the formation of a complex between the copper ions and the peptide bonds in the protein molecules. The intensity of the color depends on the concentration of the protein in the solution.

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Read lesson note on Cell Structure (WAEC)

Nutrition

Cell Structure

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Question 54 Report

The following organisms are producers except

Hibiscus

Mushroom

Cactus

Spirogyra

Answer Details

Hibiscus and Spirogyra are plants that are capable of producing their own food through photosynthesis. Cactus is also a plant that is capable of producing food, although it uses a specialized form of photosynthesis called CAM photosynthesis. On the other hand, Mushroom is not a plant and is not capable of producing its own food. It is a fungus that obtains its nutrients by decomposing organic matter. Therefore, Mushroom is the organism in the given options that is not a producer.

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Question 55 Report

Which of the following neurons may not have myelin sheath?

Effector cells

Intermediate neurons

Motor neurons

Sensory neurons

Answer Details

Sensory neurons may not have myelin sheath. Sensory neurons are responsible for transmitting signals from the sensory receptors (such as those in the skin, eyes, ears, nose, and tongue) to the central nervous system (brain and spinal cord). Some sensory neurons have long axons that extend from the periphery to the spinal cord or brain, and these axons may be covered by myelin sheath produced by Schwann cells. However, not all sensory neurons have myelin sheath. For example, some sensory neurons that are involved in transmitting pain signals may have very short or no myelin sheath. This lack of myelin sheath can contribute to the sensation of pain, as it allows the signal to be transmitted more slowly and with greater intensity.

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Protein Synthesis

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Question 56 Report

Acquired characters are

received from parents

passed to offspring

caused by the environment

caused by mutation

Heredity

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Question 57 Report

Inhaled air is made warm and moist in the

epiglottis

nasal cavity

trachea

mouth

Answer Details

Inhaled air is made warm and moist in the nasal cavity. The nasal cavity contains specialized structures called turbinates, which help to increase the surface area of the nasal cavity. As air passes through the nasal cavity, it comes into contact with the moist mucous membranes lining the cavity, which help to humidify the air and also trap any dust or particles in the air. Blood vessels in the mucous membranes also warm the air, bringing it closer to body temperature. Overall, the nasal cavity helps to prepare inhaled air for entry into the lungs, making it more suitable for respiration.

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Read lesson note on Respiratory System (WAEC)

Respiration

Animal Nutrition

Properties And Functions Of The Living Cell

Respiratory System

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Question 58 Report

The following are abiotic components of an ecosystem except

temperature

oxygen

bacteria

soil

Answer Details

The answer is "bacteria". Bacteria are living organisms and are part of the biotic components of an ecosystem. The other options, temperature, oxygen, and soil, are abiotic components of an ecosystem. Abiotic factors are non-living components of an ecosystem that can affect the growth and survival of living organisms. Temperature affects the rate of biological processes, oxygen is necessary for respiration, and soil provides nutrients and support for plants.

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Ecological Management: Tolerance, Minimum And Maximum

Ecosystem

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Question 59 Report

Which of the following statements about photosynthesis is not true?

Plants can photosynthesize without an increase in dry weight

Carbon dioxide is absorbed by the leaves in bright light

oxygen is produced during photosynthesis from the breakdown of water

Photosynthesis occurs in green plants

Answer Details

The statement that is not true about photosynthesis is "Plants can photosynthesize without an increase in dry weight." Photosynthesis is the process by which plants, algae, and some bacteria convert light energy into chemical energy stored in organic compounds such as sugars. This process occurs in specialized organelles called chloroplasts, which are found in the cells of the plant's leaves, stems, and sometimes roots. During photosynthesis, carbon dioxide and water are converted into glucose and oxygen, with the help of chlorophyll and other pigments that absorb light energy. The oxygen produced during photosynthesis comes from the splitting of water molecules, not the breakdown of water. And, photosynthesis does lead to an increase in dry weight, as the plant stores the energy in the form of organic compounds.

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Read lesson note on Nutrition (JAMB)

Nutrient Cycling In Nature

Nutrition

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