JAMB UTME - Biology - 2019

Which of the following is an example of continous variation?

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Height in humans is an example of continuous variation. This means that there is a wide range of possible heights within a population and that there is no clear division into separate categories. People can be tall, short, or anywhere in between, and there is a smooth distribution of heights rather than distinct groups. This type of variation is called continuous because the traits can take on any value within a range, rather than being limited to specific categories.

Which of the following is not a transmitable character in plants

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Haemophilia is not a transmittable character in plants. Haemophilia is a genetic disorder that affects blood clotting in humans and other animals, and it has no relevance to plants. On the other hand, the habit of growth, resistance to environmental factors, and lifespan are all heritable traits that can be transmitted from parent plants to their offspring through genetic material such as DNA. The habit of growth refers to the overall shape and size of the plant, including whether it is a tree, shrub, or herb. Resistance to environmental factors refers to a plant's ability to survive in adverse conditions such as drought, high salinity, or extreme temperatures. Lifespan refers to the length of time that a plant can live and reproduce. All of these traits are important for plant survival and are determined by genetic factors that can be passed down from one generation to the next.

Only specially adapted micro-organisms are found in

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Halophiles are organisms that thrive in high salt concentrations. The adaptations of halophile organisms to their environment are:
(a) The integrity of non-halophile macromolecules is compromised, and the flow of water out of the cell produces a Turgor effect. • (b) Moderate halophiles maintain their structures via the synthesis of compatible organic solutes. • (c) Extreme halophiles maintain their structures via equilibration of cellular and environmental salt concentrations.

Which of the following is a nitrifying bacterium?

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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.

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

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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.

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

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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.

A population is best described as

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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.

Which of the following substances pass through the root cell membrane by osmosis?

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Water passes through the root cell membrane by osmosis. Osmosis is the movement of water molecules from an area of higher concentration to an area of lower concentration across a semi-permeable membrane. In plants, water is absorbed through the root hairs of the plant and moves into the root cells. The root cell membrane is selectively permeable, meaning that it allows certain molecules to pass through while blocking others. Water molecules are small enough to pass through the membrane, but larger molecules like cell sap, carbon dioxide, and oxygen cannot pass through by osmosis. Therefore, the correct answer is water.

The part labelled a in the above diagram is used for

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

In an ecosystem, the organism which changes light energy into stored chemical energy is the

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The organism that changes light energy into stored chemical energy in an ecosystem is the producer. Producers are typically plants and algae that use photosynthesis to convert light energy from the sun into chemical energy stored in the form of glucose (sugar). This stored energy is then used as a source of food and energy for other organisms in the ecosystem. Consumers, on the other hand, are organisms that consume producers or other consumers to obtain energy. Decomposers are organisms that break down dead organic matter and return nutrients to the soil. Carnivores are consumers that eat other consumers. So, in summary, the producer is the organism that converts light energy into stored chemical energy, while consumers, decomposers, and carnivores obtain energy by eating other organisms.

Competition among individuals of a population increases the

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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.

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

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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?

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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.

The part labeled III in the above diagram is

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The part labeled III in the diagram is Hyphae. Hyphae are thread-like structures that form the main body of a fungus. They grow in a network called mycelium, which is made up of many hyphae. Hyphae are responsible for absorbing nutrients and water from the environment and transporting them to the rest of the fungus. They also play a role in the reproduction of the fungus by producing spores. Hyphae can vary in size and shape, but they are typically very thin and can grow very long, allowing the fungus to spread over a large area.

One important characteristics of green plant is that they

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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 organ removes the largest quantity of water from the blood?

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The organ that removes the largest quantity of water from the blood is the kidney. The kidney is a vital organ in the body that helps filter waste products and excess water from the blood, which are then eliminated from the body as urine. When blood enters the kidney, it passes through tiny blood vessels called capillaries. These capillaries are surrounded by small structures called nephrons, which are responsible for filtering the blood. As blood flows through the nephrons, excess water and waste products are filtered out and collected as urine. The kidneys play an important role in maintaining the body's water balance. They can adjust the amount of water that is excreted from the body depending on how much water is consumed, how much is lost through sweating, and other factors. This helps to maintain the body's fluid levels within a narrow range, which is important for proper bodily function. While the skin and lungs also play a role in removing water from the body, they are not as efficient as the kidneys. The skin eliminates water through sweat, but this process is limited by factors such as humidity and temperature. The lungs eliminate water through exhalation, but this is a small amount compared to the amount eliminated by the kidneys. Overall, the kidneys are the most important organ for removing excess water from the body, and play a critical role in maintaining proper bodily function.

Which of the following statement about the similarities in plant and animal transport is correct?

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The statement that is correct about the similarities in plant and animal transport is that materials and hormones are transported in fluid form. In both plants and animals, the transport of materials and hormones occurs through the use of fluids. In animals, blood serves as the transport medium, carrying oxygen, nutrients, and hormones to various tissues and organs. In plants, the transport medium is called sap, and it contains water, minerals, and sugars that are transported through specialized tissues called xylem and phloem. However, the other options provided in the question are incorrect. In animals, blood is made up of a variety of different tissues, not just one. And in plants and animals, materials are not transported in the same vessels. In animals, materials are transported through veins and arteries, while in plants, they are transported through xylem and phloem. Finally, while diffusion is important in both plant and animal transport, it is not the only mechanism by which materials are moved.

Possession of thin membrane enables a tapeworm to

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

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

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

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

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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 essential substance is contained in vegetable?

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Vegetable contains mineral salts like magnesium, copper etc which is very essential for body growth.

Albinism is an expression of trait controlled by

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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 is considered to be the first product of Photosynthesis?

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Starch is the main and first product formed during photosynthesis because the simple sugar formed is partly used by the plant and excess of it is converted into starch immediately for storage and the starch is transported to other parts of the plant through the phloem vessels for storage.

Which of the reproductive system in mammals secretes a part of the seminal fluid which raises the pH of the fluid in the female reproductive system?

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The Cowper's gland, also known as the bulbourethral gland, secretes a part of the seminal fluid in mammals. This gland is located near the base of the penis and its secretion is added to the semen just before ejaculation. The fluid produced by the Cowper's gland is alkaline and helps to neutralize the acidity of the female reproductive tract. This is important because it helps to create a more favorable environment for the sperm, increasing the chances of successful fertilization. The alkaline fluid also helps to protect the sperm from the corrosive effects of the acidic environment in the female reproductive tract. So, the Cowper's gland plays a crucial role in the reproductive process of mammals.

Reading the verdict of a case by a magistrate is an example of

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Reading the verdict of a case by a magistrate is an example of a voluntary action. Voluntary actions are those actions that require conscious effort and decision-making. In this case, the magistrate has to actively choose to read the verdict and make a conscious effort to understand and communicate the decision to those involved in the case. It is not a reflex action, as it does not occur automatically in response to a stimulus. It is also not an instinct or a conditioned reflex, as it is not a natural behavior or a learned response to a particular situation.

The association between two organisms living together in which only one benefits from the association while the other is neither benefited nor harmed is

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The association between two organisms living together in which only one benefits from the association while the other is neither benefited nor harmed is called commensalism. Commensalism is a type of ecological relationship that occurs when one organism benefits from the association, while the other organism is unaffected. The organism that benefits from the association is called the commensal, while the other organism is called the host. In this type of relationship, the commensal often uses the host for shelter, food, or transportation, but the host is not harmed or helped by the commensal in any way. For example, some birds and mammals, such as egrets and cattle, have a commensal relationship. The birds perch on the backs of the cattle and eat insects that are attracted to the cattle. The cattle are not affected by the presence of the birds, but the birds benefit from the association by gaining a steady source of food. In summary, commensalism is a type of ecological relationship in which one organism benefits from the association while the other is neither benefited nor harmed.

The basis of growth involves the following processes except

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The basis of growth involves the following processes except cell reduction. Growth in living organisms is the result of an increase in the size and number of cells. This is achieved through processes such as cell division, cell enlargement, and cell differentiation. Cell division involves the replication of DNA and the separation of the replicated chromosomes into two identical daughter cells. This leads to an increase in the number of cells in an organism. Cell enlargement involves an increase in the size of individual cells due to an increase in the amount of cytoplasm and organelles. This leads to an increase in the overall size of an organism. Cell differentiation is the process by which cells become specialized and take on specific functions within an organism. Cell reduction, on the other hand, involves a decrease in the size or number of cells, and is not a part of the basis of growth. Instead, cell reduction is a process that is associated with aging, disease, and other factors that can lead to a decrease in the size or number of cells in an organism.

Which of the following juices contains the enzyme ptyalin?

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The juice that contains the enzyme ptyalin is saliva. Ptyalin, also known as salivary amylase, is an enzyme that breaks down complex carbohydrates into simple sugars. It is produced by the salivary glands and released into the mouth when we eat. Ptyalin begins the process of digestion in the mouth, breaking down starchy foods such as bread and potatoes into smaller, more easily digestible molecules. Gastric juice is produced by the stomach and contains hydrochloric acid and enzymes that help break down proteins. Succus is not a specific type of juice. It can refer to any juice that is extracted from a plant or fruit. Pancreatic juice is produced by the pancreas and contains enzymes that help break down proteins, carbohydrates, and fats in the small intestine. So, the correct answer is saliva.

The glomerular filtrate contains the following except

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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.

In the theory of use and disuse Lamarck proposed that evolution occurred because of the following except

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The theory of use and disuse proposed by Lamarck stated that evolution occurs because of changes in an organism's environment, which causes an organism to develop specialised characters. These characters are then passed down to offspring, who will have a greater chance of survival because of their increased adaptation to the environment. However, Lamarck's theory was incorrect in one key aspect: he believed that these changes were acquired during an organism's lifetime and then passed down to offspring through inheritance. We now know that traits are not acquired during an organism's lifetime and passed down to offspring, but are instead inherited through genes. This is known as the theory of natural selection, which states that evolution occurs through the survival and reproduction of the fittest individuals with beneficial traits, rather than through the inheritance of acquired characteristics.

Which of the blood corpusles are irregular and amoeloid in shape

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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.

Animals are said to gregarious when

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Animals are said to be gregarious when they are of the same species and move together in a group. This behavior can be seen in various animals, such as wildebeests, zebras, and birds. There are different reasons why animals may exhibit gregarious behavior. One reason is for protection from predators. Being in a group makes it more difficult for a predator to target one individual. Animals in a group can also help defend against predators by displaying protective behaviors, such as giving an alarm to alert others when danger threatens. Another reason for gregarious behavior is for mating purposes. Some animals may form groups during breeding season, where males compete for females and display their dominance. So, the correct answer is "they are of the same species moving together in a group."

The type of nutrition in which two organisms of different species live together and derive nutrients from each other is

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The type of nutrition in which two organisms of different species live together and derive nutrients from each other is called symbiotic nutrition. In symbiotic nutrition, the two different species of organisms live together in a close relationship and mutually benefit from each other. One organism provides nutrients, such as food or shelter, to the other organism, and in return, the other organism provides nutrients or some other benefit to the first organism. This type of nutrition is also known as mutualism. Symbiotic nutrition can be found in various forms in nature. For example, the rhizobia bacteria live in the root nodules of leguminous plants and fix atmospheric nitrogen into a form that the plants can use. In return, the plants provide the bacteria with sugars and other nutrients. Another example is lichens, which are made up of a fungus and an alga living together. The fungus provides a protected environment for the alga, while the alga provides the fungus with sugars and other nutrients through photosynthesis. So, the correct answer is "symbiotic nutrition".

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

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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.

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

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The appendix is considered to be vestigial in humans but functional in other mammals. In humans, the appendix serves no known purpose and can become inflamed and cause pain (appendicitis), which often requires surgical removal. However, in other mammals such as cows and horses, the appendix serves as a fermentation chamber where beneficial bacteria can break down tough plant fibers into simpler sugars that can be easily absorbed. This process is important for their digestion and survival.

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

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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 factors is not considered in a terrestial habitat?

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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 an effect of clay soil on vegetation

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

Which of the following pairs of organisms are photosynthetic?

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The correct pair of photosynthetic organisms from the options provided are Euglena and Chlamydomonas. Both Euglena and Chlamydomonas are unicellular organisms that are capable of performing photosynthesis, which is the process of converting light energy into chemical energy. They have chloroplasts, the specialized organelles that carry out photosynthesis, and are therefore capable of producing their own food. On the other hand, Amoeba and Paramecium are heterotrophic organisms, meaning they obtain their food by consuming other organisms. Volvox is a colonial organism, which is also photosynthetic, but it is made up of many cells working together. Rhizopus is a type of fungus that obtains its nutrition through the absorption of organic material. Nostoc is a type of cyanobacteria that is capable of photosynthesis, while Plasmodium is a parasitic organism that causes malaria in humans and is not photosynthetic. So, the correct answer is "Euglena and Chlamydomonas".

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

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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.