JAMB UTME - Biology - 1992 | Green Bridge CBT

Question 1 Report

The function of the part labelled 1 is to

secrete a fluid which lubricates the joint

attach muscles to the bones at the joint

bend the bones at the joint

hold the joint in place

Answer Details

View Answer

Question 2 Report

The essential structural difference between hydra and tapeworm is that while Hydra

has tentacles, tapeworm is parasitic

is diploblastic, tapeworm is triplobastic

has a mouth, tapeworm feeds by suckers

has mesoderm, tapeworm has mesogloea

Answer Details

View Answer

Question 3 Report

The structure labelled 5 is the

nucleolus

Golgi body

mitochondrion

vacuole

Answer Details

The Golgi apparatus is an organelle present in most eukaryotic cells. It is made up of membrane-bound sacs, and is also called a Golgi body, Golgi complex, or dictyosome. The job of the Golgi apparatus is to process and bundle macromolecules like proteins and lipids as they are synthesized within the cell.

Read lesson note on Nucleic Acids (WAEC)

Read lesson note on Cell Structure (WAEC)

Nucleic Acids

Cell Structure

View Answer

Question 4 Report

Double fertilization in higher plants is significant because it ensures the

formation of a fertile embryo

formation of a fertile embryo and the endosperm

developement of the seed

developement of the fruit

Answer Details

Double fertilization in higher plants is significant because it ensures the formation of a fertile embryo and the endosperm. Double fertilization is a process that occurs during the fertilization of angiosperms (flowering plants), where two sperm cells are involved in the fertilization of the ovule. One sperm fertilizes the egg cell, leading to the formation of the zygote, which develops into the embryo. The other sperm fuses with the two polar nuclei in the central cell of the female gametophyte, leading to the formation of the endosperm. The endosperm provides nutrients to the developing embryo and is an important part of the seed. Double fertilization ensures that both the embryo and the endosperm are fertile, which is important for the successful reproduction and survival of the plant species.

Read lesson note on Integrated Water Resources Management (WAEC)

Read lesson note on Reproduction (Physical Changes In Males And Females) (WAEC)

Integrated Water Resources Management

Reproduction (Physical Changes In Males And Females)

View Answer

Question 5 Report

The structure labelled 5 is the

neucleolus

Golgi body

mitochondrion

vacuole

Answer Details

Read lesson note on Cellular Respiration (WAEC)

Read lesson note on Growth (JAMB)

Read lesson note on Nucleic Acids (WAEC)

Read lesson note on Cell Structure (WAEC)

Cellular Respiration

Growth

Nucleic Acids

Cell Structure

View Answer

Question 6 Report

5 cm3 dilute sodium hydroxide solution and 5 cm3 one percent copper sulphate solution are added to a solution of food specimen. The purple colour which is observed shows the presence of

glucose

starch

fat

protein

Answer Details

The purple colour observed after adding 5 cm3 dilute sodium hydroxide solution and 5 cm3 one percent copper sulphate solution to a solution of food specimen shows the presence of protein. This is because the Biuret test is used to detect proteins in a sample. In this test, the copper ions in the copper sulphate solution react with the peptide bonds in the protein molecule to form a purple complex. The intensity of the purple colour is directly proportional to the concentration of the protein present in the sample.

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

Read lesson note on Adaptation For Survival (WAEC)

Read lesson note on Sense Organs (Nose, Tongue & Skin) (WAEC)

DNA Structure And Replication, RNA Transcription

Adaptation For Survival

Sense Organs (Nose, Tongue & Skin)

View Answer

Question 7 Report

The flow of air and water in or out of the mesophyll layer of a leaf is controlled by the

stomata

lenticels

air space

guard cell

Answer Details

View Answer

Question 8 Report

Woman do not suffer from colour blindness because

the trait is sex-linked

only men are colour blind

the genes are recessive and sex-linked

the genes occur on both the X and Y chromosomes

Answer Details

Read lesson note on Linkage, Sex Determination And Sex Linked Characters (WAEC)

Linkage, Sex Determination And Sex Linked Characters

View Answer

Question 9 Report

Which level of the pyramid has the least total stored energy?

Answer Details

The level of the pyramid with the least total stored energy is level H. This is because as you move up the pyramid from level A to level H, there is a decrease in the amount of energy available. This is due to the loss of energy as it is transferred from one trophic level to the next through various ecological processes, such as respiration, heat loss, and incomplete digestion. At each level, only a small fraction of the energy available at the previous level is passed on. Therefore, the higher up the pyramid you go, the less energy is stored. Level H is at the top of the pyramid, which means it has the least total stored energy.

Read lesson note on Nitrogen Cycle (WAEC)

Read lesson note on Support And Movement (JAMB)

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

Nitrogen Cycle

Support And Movement

Food Webs And Trophic Levels

View Answer

Question 10 Report

A tissue can best be defined as

an aggregate of similar cells

an aggregate of cells performing a similar function

an aggregate of similar cells performing the same function

a mixture of different cells types performing the same function

Answer Details

View Answer

Question 11 Report

Soil with the finest particles is called

silt

clay

sand

gravel

Answer Details

Soil with the finest particles is called clay. Clay particles are smaller than sand and silt particles, with a diameter less than 0.002 mm. These tiny particles allow for greater surface area, which provides better water and nutrient holding capacity in the soil. Clay soils can be dense, and can have slow drainage, but can also be very fertile and productive.

Read lesson note on Soil (WAEC)

Soil

View Answer

Question 12 Report

Which of the following is true of climax community?

it persists until the enviroment or climate changes

it changes drastically from one year to the next

it is first stage in succession

It is made up of the tallest trees and the smallest

Answer Details

A climax community is the stable, final stage of ecological succession, and it persists until the environment or climate changes. It is the end result of a series of ecological changes, and it is characterized by a diverse and relatively stable community of organisms that are in equilibrium with each other and their environment. The other options provided are not true of climax community: it does not change drastically from one year to the next, it is not the first stage in succession, and it is not necessarily made up of the tallest trees and smallest organisms.

Read lesson note on Ecology Of Population (WAEC)

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

Read lesson note on Natural Habitats (JAMB)

Read lesson note on The Ecology Of Populations (JAMB)

Ecology Of Population

Co-ordination And Control

Natural Habitats

The Ecology Of Populations

View Answer

Question 13 Report

Pawpaw seeds collected from a tree with many desirable agronomic qualities did not give rise to plants of desirable character as the parent because

seeds are not reliable for propagating plants

uncontrolled out-crossing can introduced unwanted variability

vegetative propagation is best form of reproduction of all crop

seeds were not physiologically mature at the harvest

Answer Details

The reason why pawpaw seeds collected from a tree with many desirable agronomic qualities did not give rise to plants of desirable character as the parent is that uncontrolled out-crossing can introduce unwanted variability. This means that the pollen from other pawpaw trees with undesirable traits may have fertilized the flowers of the parent tree, leading to offspring with a mixture of desirable and undesirable traits. Therefore, to maintain the desirable agronomic qualities of a pawpaw tree, controlled pollination or vegetative propagation may be a better option.

Read lesson note on Growth (JAMB)

Growth

View Answer

Question 14 Report

If R and r, denotes the genes for a character, the offspring of the cross between RR and Rr are

RR, 2Rr, rr

2RR, 2rr, 2rr

2RR, 2Rr

4Rr

Answer Details

In genetics, the capital letter 'R' represents a dominant allele for a particular gene, while the lowercase letter 'r' represents a recessive allele. When an individual has two copies of the same allele, it is called homozygous (RR or rr). When an individual has one dominant and one recessive allele, it is called heterozygous (Rr). So, if RR (homozygous dominant) is crossed with Rr (heterozygous), the possible gametes for RR are R, and the possible gametes for Rr are R and r. Thus, the possible offspring are 50% RR (homozygous dominant) and 50% Rr (heterozygous). This means that the correct answer is: 2RR, 2Rr.

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

Chromosomes: The Basis Of Heredity

View Answer

Question 15 Report

In the absence of oxygen, the pyruvic acid produced during glycolysis is converted to CO2 and

water

glycerol

ethanol

citric acid

Answer Details

In the absence of oxygen, the pyruvic acid produced during glycolysis undergoes fermentation. This process converts the pyruvic acid to either lactic acid or ethanol and CO2, depending on the type of fermentation. Therefore, the correct answer to the question is ethanol.

Read lesson note on Respiration (JAMB)

Read lesson note on Cellular Respiration (WAEC)

Respiration

Cellular Respiration

View Answer

Question 16 Report

The bone of the neck on which the skull rests is known as the

odontoid process

axis

atlas

occipital condyle

Answer Details

The bone of the neck on which the skull rests is known as the "atlas". The atlas is the first cervical vertebra, located at the top of the spine, just beneath the skull. It is responsible for supporting the weight of the head and allowing the head to nod up and down. The name "atlas" comes from the mythological figure Atlas who was believed to carry the weight of the world on his shoulders.

View Answer

Question 17 Report

Which part of the curve represents the fastest rate of growth?

Answer Details

The part of the curve that represents the fastest rate of growth is labeled as M. This is because the slope of the curve is steepest at this point, indicating a rapid increase in the growth rate. As we move from left to right along the curve, the rate of growth gradually increases, reaches its maximum at point M, and then begins to decrease until it reaches zero at point N. Therefore, point M represents the peak growth rate of the organism or population.

Read lesson note on Growth (JAMB)

Growth

View Answer

Question 18 Report

An onion is a bulb because it

has a tuberous stem

has a reduced stem and thick fleshy leaves

has adventitous roots

bears many buds at the nodes

Answer Details

An onion is a bulb because it has a reduced stem and thick fleshy leaves. The leaves of the onion plant store food in the form of carbohydrates in a bulb, which is a specialized underground stem. This bulb is covered by thin, papery layers that protect the bulb and keep it from drying out. When the bulb sprouts, the stored food provides energy for the plant to grow and produce leaves, flowers, and seeds.

Read lesson note on Morphology Of Monocotyledonous And Dicotyledonous Plants (WAEC)

Read lesson note on Internal Structure Of A Flowering Plant (JAMB)

Morphology Of Monocotyledonous And Dicotyledonous Plants

Internal Structure Of A Flowering Plant

View Answer

Question 19 Report

The flowering period of plants in a habitat is determined by the

duration of sunlight

intensity and duration of rainfall

relative humidity of the atmosphere

temperature of the habitat

Answer Details

Read lesson note on Ecosystem (WAEC)

Ecosystem

View Answer

Question 20 Report

Neurons that receive stimuli from the body or internal organs are called

sensory neurons

efferent neurones

motor neurones

relay neurones

Answer Details

Neurons that receive stimuli from the body or internal organs are called sensory neurons. They are specialized cells that convert external and internal stimuli into electrical impulses, which are then transmitted to the central nervous system (CNS) for processing and interpretation. Sensory neurons are responsible for sensing different types of stimuli, such as touch, pressure, temperature, pain, sound, and light, and play a critical role in allowing organisms to respond to changes in their environment.

Read lesson note on Nervous Coordination (WAEC)

Nervous Coordination

View Answer

Question 21 Report

The theory of natural selection was developed by

Lamarck and Darwin

Darwin and Wallace

Wallace and Mendel

Mendel and Larmack

Answer Details

The theory of natural selection was developed by Charles Darwin and Alfred Russel Wallace. Darwin is often credited with the theory of evolution by natural selection, which proposes that species change over time as a result of natural selection acting on inherited variation. Wallace independently came up with a similar theory of natural selection, which he described in a letter to Darwin. Darwin then published his own ideas and credited Wallace, leading to their joint recognition as the developers of the theory of natural selection.

Read lesson note on Theories Of Evolution (JAMB)

Theories Of Evolution

View Answer

Question 22 Report

The grand period of growth is represented by

Answer Details

View Answer

Question 23 Report

Which enzymes are contained in the pancreatic juice?

Ptayalin, lipase and pepsin

Maltase, erepsin and trypsin

Renin, sucrase and lipase

Amylase, lipase and trypsin

Answer Details

Pancreatic juice contains amylase, lipase, and trypsin. Amylase is an enzyme that breaks down carbohydrates into simple sugars, lipase breaks down fats into fatty acids and glycerol, while trypsin breaks down proteins into peptides. These enzymes are important for digestion and are produced in the pancreas before being released into the small intestine to aid in the breakdown of food.

View Answer

Question 24 Report

Which of the following insects undergoes incomplete metamorphosis?

Mosquito

Termite

Housefly

Moth

Answer Details

The insect that undergoes incomplete metamorphosis is the termite. In incomplete metamorphosis, the insect hatches from an egg into a nymph that resembles an adult, but is smaller and has no wings. The nymph molts several times, each time becoming more similar in appearance to the adult, until it reaches full size and develops wings (if it is a flying species). In contrast, insects that undergo complete metamorphosis, such as the moth, have a distinct larval stage, which looks completely different from the adult, and goes through a pupal stage before emerging as an adult.

Read lesson note on Classification (WAEC)

Classification

View Answer

Question 25 Report

Which of the following correctly summarizes the life cycle of fern plant?

Spore → prothallus → thallus → sporangium

Male and female gamentangia → zygospores → sporangium → spores

Spore → thallus → spermatozoa + ovum → sporangium

Prothallus → spermatozoid → +egg cell → leafy plant → sporangium → spore

Answer Details

View Answer

Question 26 Report

The organelle involved in tissue respiration is the

endoplasmic reticulum

ribosome

golgi body

mitochondrion

Answer Details

The organelle involved in tissue respiration is the mitochondrion. Mitochondria are known as the "powerhouses" of the cell because they produce energy-rich ATP molecules through cellular respiration. Tissue respiration is the process by which cells in the body consume oxygen to produce energy in the form of ATP. This process occurs within the mitochondria, which are found in virtually all types of eukaryotic cells and are particularly abundant in tissues with high energy demands, such as muscle tissue. The other organelles listed (endoplasmic reticulum, ribosome, and golgi body) are not directly involved in cellular respiration.

Read lesson note on Cell Structure (WAEC)

Cell Structure

View Answer

Question 27 Report

The part labelled 3 is the

leaf scar

lenticle

axillary bud

girdle scar

Answer Details

The part labelled 3 is the axillary bud. An axillary bud is an embryonic shoot that is located in the angle formed between the stem and the petiole of a leaf. It has the potential to develop into a lateral branch, a thorn or a flower cluster, and is an important structure in plant propagation and growth.

View Answer

Question 28 Report

An example of plant adaptation to a xerophytic environment is represented by the development of

fleshy tissue and reduced leaves

broad canopy and extensive surface root system

thick barks and broad leaves

rough leaves and shallow root system

Answer Details

An example of plant adaptation to a xerophytic (dry) environment is represented by the development of fleshy tissue and reduced leaves. This adaptation helps plants conserve water in an environment where water is scarce. Fleshy tissue allows the plant to store water, while reduced leaves reduce water loss through transpiration. This adaptation is commonly seen in succulent plants, such as cacti, which are able to survive in hot and dry environments. By reducing the amount of water lost through transpiration and storing water in fleshy tissues, these plants are able to thrive in environments where other plants would struggle to survive.

View Answer

Question 29 Report

Hypogeal germination is characterized by the

emergency of the plumule out of the ground

provision of nourishment by the endosperm

elongation of the hypocotyl

elongation of the epicotyl

Answer Details

Read lesson note on Forms In Which Living Cells Exist (WAEC)

Forms In Which Living Cells Exist

View Answer

Question 30 Report

The structure labelled X is used by the organism in the same way as man uses his

oesophagus

trachea

stomach

intestine

Answer Details

Read lesson note on Nutrition (JAMB)

Read lesson note on Health And Hygiene (WAEC)

Nutrition

Health And Hygiene

View Answer

Question 31 Report

Which of the following is true of the children of a heamophilic man who marries a woman that is not haemophilic and does not carry the trait?

All their sons will be haemophlic

all their daughters will be haemophilic

All their daughters will be carriers

all their sons will be carriers

Answer Details

If a man has hemophilia, it means that he has a genetic mutation that affects his blood's ability to clot properly. Hemophilia is a sex-linked disorder, which means that the gene for the disorder is located on the X chromosome. Women have two X chromosomes, while men have one X chromosome and one Y chromosome. If a man with hemophilia marries a woman who is not a carrier of the disorder and does not have any affected family members, then all of their daughters will be carriers of the hemophilia gene, but none of their sons will have hemophilia or be carriers. This is because the daughters will inherit one X chromosome from their father (which has the hemophilia gene) and one X chromosome from their mother (which does not have the hemophilia gene). Since the mother does not have the hemophilia gene, she cannot pass it on to her sons. The sons will inherit their father's Y chromosome (which does not carry the hemophilia gene) and their mother's X chromosome (which also does not carry the hemophilia gene). Therefore, the correct answer is: all their daughters will be carriers.

Read lesson note on Genetic Terminologies (WAEC)

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

Genetic Terminologies

Behavioural Adaptations In Social Animals

View Answer

Question 32 Report

A population is defined as a collection of similar organism that

behave in the same way

interbreed freely

are found in the same habitat

eat the same food

Answer Details

Read lesson note on Support And Movement (JAMB)

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

Read lesson note on Natural Habitats (JAMB)

Support And Movement

Co-ordination And Control

Natural Habitats

View Answer

Question 33 Report

Fruits which develop without fertilization of the ovule are

false

multiple

aggrgate

parthenocarpic

Answer Details

Fruits which develop without fertilization of the ovule are called parthenocarpic fruits. This means that the fruit is formed without the need for pollination or fertilization. This can occur naturally or can be induced through various methods such as hormone treatments. Examples of parthenocarpic fruits include bananas, seedless grapes, and seedless watermelons. These fruits are often preferred by consumers as they have no seeds or reduced seed content, making them easier to eat and use in various food preparations.

View Answer

Question 34 Report

The structure labelled Y is the

food vacuole

nucleolous

macronucleus

contractile vacuole

Answer Details

Read lesson note on Cell Structure (WAEC)

Cell Structure

View Answer

Question 35 Report

A mammal with red fur and long ears was crossed with another having white fur and short ears. If the offspring had a red fur and short ears, the

character are linked

character are not linked

parents are related

parents are not related

Answer Details

Read lesson note on Genetic Terminologies (WAEC)

Read lesson note on Linkage, Sex Determination And Sex Linked Characters (WAEC)

Genetic Terminologies

Linkage, Sex Determination And Sex Linked Characters

View Answer

Question 36 Report

In typical predator food chain involving secondary and tertiary consumers, the organism become progressively

smaller and more numerous along the food chain

equal in number and size along the food chain

larger and fewer along the food chain

parasitized along the food chain as consumers get bigger

Answer Details

In a typical predator food chain involving secondary and tertiary consumers, the organisms become progressively larger and fewer along the food chain. This is because the energy from the primary producers (plants) is transferred to the primary consumers (herbivores) and then to the secondary consumers (carnivores) and finally to the tertiary consumers (top carnivores). As this energy is transferred, a lot of it is lost as heat or used for metabolism, so there is less and less energy available for the higher levels of the food chain. Therefore, the organisms at the top of the food chain (tertiary consumers) tend to be larger in size and fewer in number compared to those at the bottom (primary producers and herbivores).

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

Read lesson note on Reproduction (Physical Changes In Males And Females) (WAEC)

Food Webs And Trophic Levels

Reproduction (Physical Changes In Males And Females)

View Answer

Question 37 Report

Fungi are heterotropic because they

have no leaves

lack roots

are filamentous

lack chlorophyll

Answer Details

Fungi are heterotrophic because they lack chlorophyll. Chlorophyll is the green pigment found in plants that allows them to produce their own food through photosynthesis. Since fungi do not have chlorophyll, they cannot produce their own food like plants do. Instead, they obtain their nutrients from other organisms, either living or dead. This means that they have to feed on organic matter to survive, making them heterotrophic. Therefore, we can say that fungi are heterotrophic because they lack chlorophyll and cannot produce their own food through photosynthesis, so they must obtain nutrients from other sources.

Read lesson note on Modes Of Nutrition (WAEC)

Read lesson note on Protein Synthesis (WAEC)

Modes Of Nutrition

Protein Synthesis

View Answer

Question 38 Report

Fossil records found in sedimentary rocks offer some explanation for the theory of evolution because

the deposit have remains of organisms characteristic of when they were formed

different strata have remains of organisms of the same kind

only organisms with strong parts are fossilized

most animal and plant fossils bear little resemblance to present day living specimens

Answer Details

Fossil records found in sedimentary rocks offer some explanation for the theory of evolution because the deposits have remains of organisms characteristic of when they were formed. Sedimentary rocks are formed over time from sedimentation, and when plants or animals die, they may become buried in sediment, which over time becomes rock. The remains of these organisms can be preserved in the rock as fossils. By studying these fossils, scientists can determine what kind of organisms lived in the past, how they evolved, and what their characteristics were. Fossils found in different layers of sedimentary rock also show how organisms changed over time, supporting the theory of evolution. Therefore, fossil records are an important source of evidence for the theory of evolution.

Read lesson note on Theories Of Evolution (JAMB)

Read lesson note on Evolution (Theories and Evidence) (WAEC)

Theories Of Evolution

Evolution (Theories and Evidence)

View Answer

Question 39 Report

The hereditary materials of the cell is

the R N A

protein

the D N A

carbohydrate

Answer Details

The hereditary materials of the cell is the DNA (Deoxyribonucleic acid). DNA is a complex molecule that carries genetic information that determines the characteristics of living organisms. It is found in the nucleus of cells and also in some organelles such as mitochondria and chloroplasts. DNA is made up of four basic building blocks called nucleotides, and the sequence of these nucleotides carries the genetic code. DNA is responsible for transmitting genetic information from one generation to the next through the process of replication, which occurs before cell division.

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

DNA Structure And Replication, RNA Transcription

View Answer

Question 40 Report

Gaseous exchange in Aves occurs in the

tracheoles

bronchi

air sacs

trachea

Answer Details

Gaseous exchange in Aves (birds) occurs in the air sacs. These air sacs are connected to the lungs and extend throughout the bird's body, including into the hollow bones. As the bird breathes, air moves through the trachea and into the posterior air sacs, then into the lungs, and finally into the anterior air sacs before being expelled out of the body. During this process, the air sacs act as bellows, keeping air constantly flowing over the respiratory surfaces of the lungs, ensuring efficient gas exchange. Therefore, the correct answer is option C - air sacs.

Read lesson note on Respiratory System (WAEC)

Respiratory System

View Answer

Question 41 Report

Mangrove swamp can be found

on a seashore with flat terrains

where a river meets the sea

on a mud flat near the sea

where two rivers meet

Answer Details

Mangrove swamps can be found where a river meets the sea. They are coastal wetlands that are typically found in tropical and subtropical regions. The mangrove trees that make up these swamps are adapted to living in brackish water, where freshwater from the river mixes with saltwater from the sea. This unique ecosystem is important for protecting coastlines from erosion, providing habitats for a variety of plant and animal species, and serving as a nursery for many fish and shellfish species.

Read lesson note on Ecosystem (WAEC)

Ecosystem

View Answer

Question 42 Report

Melanin and keratin are produced in the part labelled

Answer Details

Read lesson note on Cell Structure (WAEC)

Cell Structure

View Answer

Question 43 Report

Which of the following factors is LEAST likely to affect the animals living in a fresh water habitat?

Turbidity

Temperature

Salinity

Answer Details

Salinity is the least likely factor to affect animals living in a freshwater habitat. Salinity refers to the concentration of dissolved salts in water, and since freshwater habitats have low salt concentration, the animals that live there have adapted to these conditions. On the other hand, turbidity, temperature, and pH are all important factors that can affect the health and survival of animals in freshwater habitats. Turbidity, for instance, can reduce the amount of light that penetrates the water, affecting the growth of aquatic plants and the ability of animals to find food. Temperature and pH, on the other hand, can affect the metabolic processes of aquatic organisms, and extreme variations in these factors can be harmful or even lethal to some species.

Read lesson note on Excretory System (WAEC)

Read lesson note on Energy Transformation In Nature (WAEC)

Read lesson note on Factors Affecting The Distribution Of Organisms (JAMB)

Read lesson note on Relevance Of Biology To Agriculture (WAEC)

Excretory System

Energy Transformation In Nature

Factors Affecting The Distribution Of Organisms

Relevance Of Biology To Agriculture

View Answer

Question 44 Report

A child with blood group genotype different from those of both parents and with a mother of genotype OO, can only have a father of genotype

Answer Details

If a child has a blood group genotype that is different from both parents and the mother has a genotype of OO, it means that the child must have inherited an allele from the father that is different from O. Since the mother's genotype is OO, she can only contribute an O allele to the child. This means that the father must have contributed either an A, B or AB allele to the child, since these are the only other possible blood group alleles. Therefore, the father of the child can only have a genotype of either A, B, or AB.

Read lesson note on Heredity (JAMB)

Heredity

View Answer

Question 45 Report

A major difference between platyhelminthees and coelenterates is that platyhelminthes

are multicellular

have developed a mesoderm

reproduce sexually

reproduce asexually

Answer Details

A major difference between platyhelminthes and coelenterates is that platyhelminthes have developed a mesoderm. The mesoderm is a middle layer of cells that lies between the endoderm (innermost layer) and the ectoderm (outermost layer) in most triploblastic animals. Platyhelminthes are triploblastic animals, which means they have three germ layers (ectoderm, mesoderm, and endoderm). In contrast, coelenterates are diploblastic animals, which means they have only two germ layers (ectoderm and endoderm) and do not have a mesoderm. The development of a mesoderm is an important evolutionary advancement because it allows for the development of more complex organs and systems in animals, such as muscles, circulatory systems, and kidneys. Therefore, the development of a mesoderm is a significant difference between platyhelminthes and coelenterates.

Read lesson note on Classification (WAEC)

Classification

View Answer

Question 46 Report

In mammalian development, the function of the yolk is to

supply nutrients to the embryo

act as the shock-absorber to the foetus

supply air to the embryo

facilitates the process of excretion in the foetus

Answer Details

Mammals are classified as placental or non-placental mammals. Non-placental mammals have eggs with a large yolk sac which provides nutrients to the developing embryo. However, placental mammals, including humans, do not have a yolk sac in their embryos. Instead, the placenta serves as a connection between the mother's blood supply and the developing embryo, providing nutrients, oxygen and removing waste. Therefore, in mammalian development, the yolk sac does not have a function in placental mammals.

Read lesson note on Organization Of Life (WAEC)

Organization Of Life

View Answer

Question 47 Report

Which organism in the pyramid functions as a tertiary consumer?

Algea

Shark

Tadpole

Tilapia

Answer Details

A tertiary consumer is an organism that eats secondary consumers. In the given pyramid, the shark is the only organism that feeds on other consumers, specifically small fish that are secondary consumers. Therefore, the shark functions as a tertiary consumer.

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

Food Webs And Trophic Levels

View Answer

Question 48 Report

Malaria symptoms are caused by

toxins released into the blood as a result of the destruction of red blood cell

the multiplication of the malaria sporozites in the liver

the invasion of the red blood cells by the trophozoites

the development of merozoites into gametocytes

Answer Details

Read lesson note on Biology And Water Industry (WAEC)

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

Biology And Water Industry

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

View Answer

Question 49 Report

The excretory organ in insects is the

kidney

malpighian tubule

flame cell

nephridium

Answer Details

The excretory organ in insects is the malpighian tubule. Malpighian tubules are long, slender tubes in insects that are involved in the excretion of metabolic waste products, primarily uric acid. They are connected to the gut and actively transport waste products from the hemolymph into the gut, where they can be eliminated from the body. Insects do not have kidneys like vertebrates do, so malpighian tubules serve as their primary excretory organs.

Read lesson note on Excretory Systems And Mechanisms; Types Of Excretory Systems (WAEC)

Excretory Systems And Mechanisms; Types Of Excretory Systems

View Answer

Question 50 Report

The blood vessel which carries blood from the alimentary canal to the liver is the

hepatic artery

hepatic vein

hepatic portal vein

mesenteric artery

Answer Details

The blood vessel which carries blood from the alimentary canal (the digestive tract) to the liver is the hepatic portal vein. This vein collects nutrient-rich blood from the intestines and transports it to the liver, where the nutrients are processed and stored. The hepatic portal vein is important in regulating glucose metabolism, detoxifying harmful substances, and maintaining overall body homeostasis.

Read lesson note on Transport System (WAEC)

Transport System

View Answer






Press & Hold to Drag Around
Click Here to Close