JAMB UTME - Biology - 2019

Which of the following are components of glomerular filtrate?

Maelezo ya Majibu

The components of glomerular filtrate are water, electrolytes (such as salts), small organic molecules (such as glucose and amino acids), and waste products (such as urea). Glomerular filtrate is formed in the kidneys and is the fluid that is filtered from the blood in the glomerulus, a network of tiny blood vessels in the kidney. The filtrate contains all the components of blood except for plasma proteins and red and white blood cells. In other words, glomerular filtrate is the fluid that is filtered from the blood and contains all the components of the blood except for large proteins and cells. It is an important step in the process of urine formation, as the filtrate travels through the renal tubules, where it is further modified and waste products are removed to form urine.

The insect trapping movements of the leaves of the venus fly trap is a behavioural adaptation for

Maelezo ya Majibu

The insect trapping movements of the leaves of the Venus flytrap is a behavioral adaptation for obtaining food. The Venus flytrap is a carnivorous plant that is native to the southeastern United States. Its leaves are modified in a unique way to trap and digest insects. The leaves of the Venus flytrap are divided into two lobes that are hinged together. The leaves also have tiny trigger hairs on their inner surfaces. When an insect touches these trigger hairs, the lobes of the leaf snap shut, trapping the insect inside. The leaf then secretes digestive enzymes that break down the insect's body, providing the plant with nutrients it needs to survive. This behavior is an adaptation that allows the Venus flytrap to live in nutrient-poor soil environments. By being able to capture and digest insects, the Venus flytrap is able to supplement its diet with the nutrients it needs to survive. So, the correct answer is "obtaining food."

The sum total of adaptive changes from pre-existing form that have taken place over a long time resulting in diversity of forms, structures and functions among organism is referred to as

Maelezo ya Majibu

The sum total of adaptive changes from pre-existing forms that have taken place over a long time resulting in diversity of forms, structures, and functions among organisms is referred to as Evolution. This process of organic evolution involves changes in the genetic makeup of populations of organisms over time, resulting in new species that are better adapted to their environment. These changes occur due to natural selection, genetic drift, mutation, and gene flow, and can lead to the development of diverse forms, structures, and functions among organisms. , Specification, is not a term used in evolutionary biology. Inorganic Evolution, is not a recognized term in biology, as evolution only applies to living organisms. Evolution, is the correct answer, but to be more specific, the full term is Organic Evolution. Organic Evolution, is also a correct answer that specifically refers to the evolution of living organisms.

Inheritable character/features possessed by an organism can be referred to as

Maelezo ya Majibu

Genes are the inheritable character/features possessed by an organism. They are the basic unit of heredity and carry information from one generation to the next. A gene is a segment of DNA that contains the instructions for making a specific protein. The proteins made by genes control the growth, development, and function of our bodies. Each of us has many thousands of genes, which together determine our traits and characteristics. So, genes are the underlying cause of the traits and characteristics that are passed down from parent to offspring.

Which of the following structures controls the activities of the living cell?

Maelezo ya Majibu

The structure that controls the activities of the living cell is the nucleus. The nucleus is a membrane-bound organelle that contains the genetic material (DNA) of the cell. It serves as the control center for the cell, directing all of its activities by regulating the expression of genes. The DNA in the nucleus provides the instructions for making proteins, which are the building blocks of the cell and carry out various functions in the body. The nucleus also plays a critical role in cell division, which is the process by which new cells are formed. During cell division, the DNA in the nucleus is replicated and then distributed to the daughter cells, ensuring that they each receive a complete set of genetic material. In summary, the nucleus is responsible for regulating gene expression and directing all of the activities of the cell. It is the structure that controls the fundamental processes of life, making it a vital organelle in all living organisms.

The following processes are involved during expiration in man except

Maelezo ya Majibu

The process involved during expiration in humans that is not accurate is "The thoracic cavity first increases in volume." During expiration, the diaphragm, which is a muscle located at the bottom of the thoracic cavity, relaxes and moves upwards, decreasing the volume of the thoracic cavity. At the same time, the intercostal muscles, located between the ribs, also relax, and the ribs move downward and inward, causing the chest to decrease in size. Additionally, the sternum moves outward, not inward, during expiration. These combined actions increase the pressure within the thoracic cavity, forcing air out of the lungs. Overall, expiration is a passive process that does not require the use of energy, and it is the opposite of inspiration, which is the process of taking air into the lungs.

Viruses are pathogens of the following diseases except

Maelezo ya Majibu

Viruses are not the pathogens of Tuberculosis. Tuberculosis is caused by the bacterium Mycobacterium tuberculosis. While viruses can weaken the immune system, making it more susceptible to other infections, including tuberculosis, the actual cause of tuberculosis is the bacterium, not a virus.

The above organism can be classified under which phylum in the animal kingdom

Maelezo ya Majibu

The tilapia fish can be classified under chordata phylum in the animal kingdom.

The glomerular filtrate contains the following except

Maelezo ya Majibu

The glomerular filtrate contains all of the substances listed except blood corpuscles. The glomerular filtrate is a fluid that is filtered from the blood in the kidneys through a specialized structure called the glomerulus. This fluid contains water, small molecules like glucose, amino acids, and urea, and ions like sodium, potassium, and chloride. Blood corpuscles, also known as blood cells, are not normally present in the glomerular filtrate because they are too large to pass through the small pores in the glomerular capillaries. Blood cells are important components of blood that help to transport oxygen, fight infection, and support the body's immune system. The glomerular filtrate is a crucial step in the process of urine formation, as it allows for the selective reabsorption of important substances like water and glucose while removing waste products like urea. The remaining fluid is then processed by the kidney tubules to form urine, which is eventually excreted from the body. It is important to note that the composition of the glomerular filtrate can vary depending on a person's diet, hydration status, and overall health, and that disorders of the kidneys can affect the ability of the kidneys to filter and process this fluid correctly.

Albinism is an expression of trait controlled by

Maelezo ya Majibu

Albinism is an expression of a trait controlled by recessive genes. Albinism is a genetic condition that results in a lack of melanin, a pigment that provides color to the skin, hair, and eyes. The condition is caused by mutations in genes that produce or distribute melanin. In order for an individual to have albinism, they must inherit two copies of the mutated gene, one from each parent. If an individual inherits one normal gene and one mutated gene, they will not have albinism, but they will be a carrier of the condition and can pass it on to their offspring. This is why albinism is considered a recessive trait, meaning it is only expressed when two copies of the mutated gene are present. So, in summary, albinism is an expression of a trait controlled by recessive genes, meaning that it is caused by mutations in genes that produce or distribute melanin, and it is only expressed when two copies of the mutated gene are present.

Which of the following pairs of scientists discovered the Rhesis factor in human blood?

Maelezo ya Majibu

The pair of scientists who discovered the Rhesis factor in human blood is Landsteiner and Levine. Karl Landsteiner was an Austrian biologist and physician who is best known for his discovery of the ABO blood group system. In 1940, he and his colleague Alexander S. Wiener discovered the Rh factor, which is a protein that is found on the surface of red blood cells in some individuals and can cause an immune response in others. This discovery was a significant breakthrough in the field of blood transfusion and helped to reduce the risk of transfusion reactions in patients. Levine is likely a reference to Philip Levine, an American immunologist who worked with Landsteiner and Wiener at the Rockefeller Institute for Medical Research in New York. Levine played a key role in the discovery of the Rh factor, conducting many of the experiments that helped to confirm the existence of the protein. Neither Hooke nor Darwin were involved in the discovery of the Rh factor in human blood. Robert Hooke was a 17th-century English scientist who made important contributions to the fields of microscopy, physics, and biology, while Charles Darwin was a 19th-century British naturalist who is best known for his theory of evolution by natural selection. In summary, the correct answer is Landsteiner and Levine, as they were the scientists who discovered the Rh factor in human blood.

Rabbits cannot survive in an aquatic habitat because they have

Maelezo ya Majibu

Rabbits cannot survive in an aquatic habitat because they have no gills. Gills are specialized organs that allow fish and other aquatic animals to extract oxygen from water. Without gills, rabbits would be unable to breathe underwater and would quickly suffocate. Additionally, rabbits are not built for an aquatic lifestyle. They have short legs and are not adapted for swimming or propelling themselves through water. While they may be able to paddle around for a short period of time, they would eventually tire and be unable to keep themselves afloat. This is why rabbits are best suited to a terrestrial habitat where they can easily breathe and move around.

Trees in Savanna habitats usually have thick bark which mainly.

Maelezo ya Majibu

Rate of transpiration is reduced in savannah forest due to thick barks of the trees in savannah forest.

One of the following is a process of transmission of hereditary characteristics by chromosomes

Maelezo ya Majibu

Dictating the formation of a protein by a gene in a chromosome is a process of transmitting hereditary characteristics

Which of the following statement describes an autonomic nervous system

Maelezo ya Majibu

The statement that describes the autonomic nervous system is "It affects glands, cardiac muscles, and smooth muscles." The autonomic nervous system is a branch of the nervous system that regulates involuntary body functions, such as heart rate, digestion, and breathing. It is composed of two subdivisions: the sympathetic and parasympathetic nervous systems. The autonomic nervous system is responsible for regulating the activity of glands, such as sweat and salivary glands, as well as the contraction of cardiac and smooth muscles, which are found in the walls of organs and blood vessels. These activities are not under conscious control and are regulated by the autonomic nervous system in response to changes in the environment, such as stress or changes in temperature. In contrast, voluntary activities, such as moving our limbs or speaking, are controlled by the somatic nervous system, which is another branch of the nervous system.

Which of the following is an example of discontinous variatio?

Maelezo ya Majibu

Discontinuous variation is the differences of variations in behaviour by which organisms can be grouped into 2 or more classes within a population without any intermediates among them e.g Behaviour, ability to roll tongue.

The part labelled a in the above diagram is used for

Maelezo ya Majibu

Operculum or gill cover helps the tilapia fish in gaseous exchange.

The organic molecule(s) present in the nucleus is/are

Maelezo ya Majibu

The main organic molecule present in the nucleus is DNA (Deoxyribonucleic Acid). DNA is the genetic material that contains the instructions for the development, function, growth, and reproduction of all living things. It is a long, double-stranded molecule that is organized into structures called chromosomes. The information in DNA is encoded in a sequence of four nitrogenous bases: adenine (A), guanine (G), cytosine (C), and thymine (T). This sequence determines the genetic code and controls the expression of genes, which are the functional units of heredity. In addition to DNA, the nucleus also contains other organic molecules, such as RNA (Ribonucleic Acid) and proteins, which play important roles in the regulation and expression of genetic information. However, DNA is the central and most critical molecule in the nucleus, as it carries the blueprint for life.

Which of the following type of soil has the highest water retaining capacity?

Maelezo ya Majibu

Among the options listed, clay has the highest water retaining capacity. This is because clay particles are very small and have a large surface area, allowing them to attract and hold onto water molecules tightly through a process called adsorption. Additionally, the spaces between the clay particles are very small, which creates a high capillary action that further helps the clay to retain water. In contrast, sand particles are much larger and have a lower surface area, which means that water molecules are less likely to adhere to them. Sand also has larger spaces between its particles, which results in a lower capillary action and less water retention. Loam and laterite fall somewhere in between clay and sand in terms of their water retention capabilities, depending on their specific composition.

Which of the following organs can be considered vestigial in humans but functional in other mammals

Maelezo ya Majibu

The appendix can be considered vestigial in humans but functional in other mammals. The appendix is a small pouch-like organ attached to the large intestine. In many other mammals, the appendix serves as a functional part of the digestive system, helping to break down cellulose and other tough plant materials that are difficult to digest. However, in humans, the appendix is considered vestigial, which means it is a structure that has lost its original function over the course of evolution. While the appendix may have had a digestive function in our distant ancestors, today it appears to have no essential role in our digestive system. However, the appendix does contain lymphoid tissue, which plays a role in the immune system, particularly during early childhood. This suggests that the appendix may still have some function in the immune system, though its exact role is not yet fully understood. In rare cases, the appendix can become inflamed and infected, leading to a condition called appendicitis. If left untreated, appendicitis can be life-threatening. In such cases, the appendix is removed through surgery, and the individual can still live a healthy life without any ill effects. In summary, the appendix is considered vestigial in humans, meaning it has lost its original function in the course of evolution. While it may still have some minor immune-related functions, it is not considered essential for human health, and in some cases, it can even be harmful if it becomes infected.

Which of the following controls all voluntary actions

Maelezo ya Majibu

The cerebrum controls all voluntary actions. The cerebrum is the largest part of the brain and is responsible for controlling movement, sensation, thought, and emotion. It is divided into two hemispheres, the left and the right, each of which controls different functions. The cerebrum is responsible for conscious decision making and voluntary movements, such as moving your arm or leg. The other options you listed, the olfactory lobes, hypothalamus, and pons varolii, have different functions in the brain. The olfactory lobes are responsible for the sense of smell, the hypothalamus controls basic functions like hunger and thirst, and the pons varolii is involved in breathing and other autonomic functions.

Which of the following factors is not considered in a terrestial habitat?

Maelezo ya Majibu

Turbidity is not typically considered a factor in a terrestrial habitat. A terrestrial habitat is a place where land-dwelling organisms, such as plants and animals, live and interact with their environment. Temperature, sunlight, and humidity are all important factors in determining the characteristics of a terrestrial habitat and the organisms that live there. Temperature affects the rate of biochemical reactions in organisms, while sunlight provides energy for photosynthesis in plants and affects the behavior of many animals. Humidity, or the amount of moisture in the air, can affect the water balance of plants and animals. On the other hand, turbidity refers to the cloudiness or haziness of a fluid, such as water, due to the presence of suspended particles. Turbidity is typically associated with aquatic habitats, where it can affect the penetration of light and the availability of nutrients for aquatic plants and animals. In a terrestrial habitat, there is generally no water for particles to be suspended in, so turbidity is not usually a significant factor.

One of the following is not the theory of natural selection stated by Charles Dawin

Maelezo ya Majibu

The theory of natural selection stated by Charles Darwin is not "Characteristics acquired through use or disuse are transmitted to offspring". This idea is sometimes referred to as "Lamarkism," and it was popular before Darwin's theory of natural selection became widely accepted. The theory of natural selection states that variations that are beneficial for survival and reproduction are more likely to be passed on to the next generation, while variations that are harmful are less likely to be passed on. However, the theory does not suggest that the use or disuse of a particular trait can directly cause it to be transmitted to offspring. Instead, the transmission of traits is determined by the genetic information that is passed from parents to offspring.

Which of the following statement is correct about Southern Guinea Savanna in Nigeria

Maelezo ya Majibu

Southern Guinea Savanna is the largest of all biotic community in Nigeria found in Oyo, Osun, Ekiti Status etc.

Which of the following substances has the highest amount of energy in joules per unit weight?

Maelezo ya Majibu

Fats have the highest amount of energy in joules per unit weight compared to carbohydrates, proteins, and vitamins. This is because fats contain more carbon and hydrogen atoms than carbohydrates and proteins, and these atoms have a higher potential to release energy when they are broken down and burned during cellular respiration. One gram of fat provides about 9 calories (37.7 kJ) of energy, while one gram of carbohydrates or proteins provides only about 4 calories (16.7 kJ) of energy. Vitamins, on the other hand, are not significant sources of energy and play important roles in supporting various metabolic processes in the body. To put it simply, fats contain more energy per unit weight than other substances because they are made up of more energy-rich carbon and hydrogen atoms.

Good quality food will perform the following functions in human except

Maelezo ya Majibu

Good quality food is essential for the proper functioning of the human body. It provides us with the nutrients that we need to stay healthy and strong. However, it is important to note that good quality food cannot provide resistance against malaria. Malaria is a disease that is caused by a parasite that is transmitted through the bite of an infected mosquito. While good nutrition can help support a healthy immune system, it cannot provide specific resistance against malaria. The other functions listed are all important roles that good quality food can perform in the human body. 1. Supplying energy: Food provides us with the energy we need to carry out daily activities, from walking and talking to more strenuous activities like exercising or playing sports. 2. Maintaining health: Eating a balanced diet that includes a variety of nutrient-rich foods helps to maintain good health. Nutrients like vitamins, minerals, and antioxidants are important for proper bodily function and can help prevent chronic diseases. 3. Sustaining growth: Children and teenagers require a balanced diet to support their growth and development. A diet rich in nutrients like protein, calcium, and iron is essential for building strong bones, muscles, and other tissues. In summary, good quality food is important for supplying energy, maintaining health, and sustaining growth. However, it cannot provide specific resistance against malaria or other infectious diseases.

One of the following is an effect of clay soil on vegetation

Maelezo ya Majibu

Clay soil's effect on vegetation is that it supports light vegetation such as forest and luxuriant vegetation.

Which of the following is a nitrifying bacterium?

Maelezo ya Majibu

A nitrifying bacterium is a type of bacterium that is capable of converting nitrogen compounds from one form to another. Out of the options you provided, the correct nitrifying bacterium is Nitrobacter. Nitrobacter is a genus of bacteria that oxidizes nitrite (NO2-) to nitrate (NO3-). This process is called nitrification and is an important part of the nitrogen cycle in the environment.

Possession of thin membrane enables a tapeworm to

Maelezo ya Majibu

The tapeworm possesses a thin membrane mostly because of it absorption of digested food from the intestine of the host.

What type of vertebrate assists in breathing alongside with the ribs?

Maelezo ya Majibu

The type of vertebrate that assists in breathing alongside the ribs are thoracic vertebrates. The thoracic region of the spine is located in the upper and middle back, and it is the region that supports the ribcage. In thoracic vertebrates, the ribs are attached to the vertebrae and to the sternum, or breastbone, forming a protective cage around the heart and lungs. During breathing, the diaphragm muscle contracts and flattens, which increases the volume of the chest cavity and draws air into the lungs. At the same time, the ribcage expands, which further increases the volume of the chest cavity and helps to pull air into the lungs. The ribs play a crucial role in this process by expanding and contracting with each breath. In addition to the diaphragm muscle, the muscles between the ribs, called intercostal muscles, also contract and relax to help move air in and out of the lungs. Sacral, caudal, and lumbar vertebrates do not have the same type of ribcage as thoracic vertebrates and therefore do not rely on the expansion and contraction of ribs for breathing. Instead, these vertebrates have other adaptations that allow them to breathe efficiently in their respective environments. For example, fish extract oxygen from water through their gills, while reptiles and some mammals, such as whales and dolphins, can hold their breath for long periods of time underwater.

A population is best described as

Maelezo ya Majibu

A population is best described as a group of individuals of the same species that live together in the same area and can potentially interact with each other. For example, a population of deer living in a forest would consist of all the individual deer of the same species that live in that forest and are able to mate with each other. This definition excludes which includes plants and animals of different species living together, and which includes different species of wild animals. includes only a specific subset of organisms, and is not a comprehensive definition of a population.

One of the major ways in which the blood is able to defend the body against disease causing organisms is

Maelezo ya Majibu

One of the major ways in which the blood is able to defend the body against disease-causing organisms is through a process called clumping, also known as agglutination. When foreign substances such as bacteria or viruses enter the bloodstream, the immune system produces specific proteins called antibodies that can recognize and bind to these foreign substances. Once the antibodies bind to the foreign substances, they can then cause the foreign substances to clump together or agglutinate. This clumping makes it easier for other immune cells to detect and destroy the foreign substances. For example, white blood cells called macrophages can engulf and destroy clumps of foreign substances that have been marked by antibodies. , Absorption of fatty acids and glycerol, is not related to the immune system's defense against disease-causing organisms. Single circulation, and Translocation, are terms related to circulatory system physiology, and are not related to the immune system's defense against disease-causing organisms.

In natural selection, Darwin proposed that evolution occurred because of the following conditions except

Maelezo ya Majibu

The exception to Darwin's proposed conditions for natural selection is "food and other needs are abundant." In Darwin's theory of evolution by natural selection, he proposed that nature selects those organisms that are best adapted to their environment, and those that are not well-adapted will not survive and reproduce. This selection process occurs because resources such as food and other necessities are limited, and only those that are able to obtain these resources will survive and reproduce. If resources were abundant, there would be no need for competition, and selection would not occur.

One important characteristics of green plant is that they

Maelezo ya Majibu

Green plants are autotropic. This means that they are able to produce their own food through a process called photosynthesis. During photosynthesis, plants use energy from sunlight, carbon dioxide from the air, and water from the soil to produce glucose, which is their source of energy. This characteristic sets plants apart from animals and other organisms that are heterotrophic and rely on other organisms for their food.

Which of the blood corpusles are irregular and amoeloid in shape

Maelezo ya Majibu

The irregular and amoeboid-shaped blood corpuscles are called "Leucocytes," which are also known as white blood cells. Leucocytes are an essential part of our immune system, and their main function is to protect the body against infections, diseases, and foreign invaders. Unlike erythrocytes (red blood cells) and thrombocytes (platelets), which have a uniform, round shape, leucocytes are irregular and amoeboid in shape, allowing them to move freely throughout the body and easily pass through the walls of blood vessels to reach the site of infection or injury. Leucocytes are classified into two main types: granulocytes and agranulocytes, based on the presence or absence of granules in their cytoplasm. Granulocytes have granules in their cytoplasm and include neutrophils, eosinophils, and basophils, while agranulocytes lack granules and include lymphocytes and monocytes. Overall, leucocytes play a critical role in our immune system and help keep us healthy by identifying and fighting off pathogens and foreign invaders.

Which of the following is the effect of using artificial pollination in plant breeding?

Maelezo ya Majibu

The effect of using artificial pollination in plant breeding is "Improvement of the variety of crops". Artificial pollination is the process of manually transferring pollen from one flower to another to fertilize it, with the goal of producing hybrid plants with desirable traits. This allows plant breeders to combine traits from two different plants to create a new variety with improved qualities such as increased yield, disease resistance, and improved flavor. By using artificial pollination, plant breeders can control the genetics of the resulting offspring, leading to the creation of new crop varieties with improved traits. This can help to increase food production and improve the quality of crops, making them more resilient and better suited for different growing conditions.

Competition among individuals of a population increases the

Maelezo ya Majibu

Competition among individuals of a population increases the "Survival of the fittest". This means that individuals that are better adapted to their environment and can compete more effectively for resources are more likely to survive and reproduce, passing on their advantageous traits to their offspring. Over time, this process can lead to the evolution of a population and can result in the survival of the strongest, most fit individuals. In a simple way, it's like a race where the fastest runner wins and gets to advance to the next round. Similarly, in a population, the individuals who are best equipped to survive and thrive will be more likely to do so, while those who are not as well adapted may struggle and eventually die off.

Plants which can survive in extremely dry places are called

Maelezo ya Majibu

The plants which can survive in extremely dry places are called xerophytes. Xerophytes have special adaptations that allow them to conserve water and survive in arid or desert environments where water is scarce. These adaptations include things like thick, waxy leaves to reduce water loss through evaporation, deep root systems to reach water deep underground, and small, spiky leaves to reduce surface area and water loss. Examples of xerophytes include cacti, succulents, and some types of grasses.

The presence of ______ for swimming in a tad-pole enables it to adapt in an aquatic habitat.

Maelezo ya Majibu

Tadpole's ability to swim and adapt to an aquatic habitat is due to the presence of its tail.

The period of inactivity seen in some animals during long period of heat or drought is

Maelezo ya Majibu

The period of inactivity seen in some animals during long periods of heat or drought is called aestivation. Aestivation is a type of dormancy, similar to hibernation, but it occurs in response to hot or dry conditions, while hibernation occurs in response to cold or food scarcity. During aestivation, animals reduce their metabolic activity and enter a state of deep sleep to conserve energy and water until more favorable conditions return. This strategy helps them survive harsh environmental conditions and avoid dehydration, which can be deadly in hot and dry environments. Some animals that undergo aestivation include certain snails, frogs, and turtles, as well as some mammals like the marsupial mouse and the fat-tailed dwarf lemur.