JAMB UTME - Biology - 2019

Détails de la réponse

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.

Détails de la réponse

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.

Détails de la réponse

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".

Détails de la réponse

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.

Détails de la réponse

In plants, respiration occurs in all living cells. Respiration is the process by which cells break down glucose to release energy that is necessary for the plant to carry out its life processes, such as growth, maintenance, and reproduction. While the stomata and lenticels are structures involved in gas exchange, they do not carry out the process of respiration. Similarly, while mesophyll cells are specialized cells involved in photosynthesis, they are not the only cells involved in respiration. All living cells, including those in the roots, stems, leaves, and reproductive organs, carry out respiration to produce energy. The oxygen needed for respiration enters the cells through the stomata and is transported to the cells by the circulatory system of the plant. The carbon dioxide produced by respiration is released from the cells and can be used by nearby cells for photosynthesis. In summary, respiration occurs in all living cells in plants and is a crucial process for plant survival and growth.

Détails de la réponse

The specific portion of a habitat that is occupied by a particular species is referred to as its "Ecological Niche". An ecological niche refers to the role and position a species has in its environment, including its relationships with other species, the way it obtains food and resources, and the physical conditions it requires to survive. Essentially, it's the species' unique way of life and how it fits into its habitat. For example, a bird species might have a specific ecological niche as a seed-eater, and it might occupy a certain area of a forest where seeds are abundant. Another species might occupy a different niche as a predator, hunting for insects in a different part of the forest. These two species have their own unique ecological niches and do not overlap in the way they interact with their environment.

Détails de la réponse

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.

Détails de la réponse

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.

Détails de la réponse

The type of nutrition shown by Spirogyra is holophytic. Holophytic nutrition, also known as autotrophic nutrition, is a type of nutrition where an organism synthesizes its own food from inorganic substances, such as carbon dioxide and water, using energy from the sun through the process of photosynthesis. Spirogyra is a type of filamentous green algae that belongs to the group of plants that can carry out photosynthesis to produce their own food. These plants contain chloroplasts, which are specialized organelles that contain chlorophyll, the pigment that absorbs light energy from the sun. During photosynthesis, Spirogyra takes in carbon dioxide and water and uses energy from sunlight to produce glucose and oxygen. This process is essential for the growth and survival of Spirogyra and other autotrophic organisms.

Détails de la réponse

A virus is often considered a living organism because it can reproduce inside living cells. This means that it uses the machinery of the host cell to make copies of itself. However, viruses do not have the ability to carry out all the processes of life, such as producing energy and growing on their own. They rely on the host cell to perform these functions for them. So, whether a virus is considered living or not is still a matter of debate among scientists.

Détails de la réponse

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

Détails de la réponse

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

Détails de la réponse

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.

Détails de la réponse

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.

Détails de la réponse

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.

Détails de la réponse

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.

Détails de la réponse

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.

Détails de la réponse

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

Détails de la réponse

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.

Détails de la réponse

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.

Détails de la réponse

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.

Détails de la réponse

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.

Détails de la réponse

Ecology is best defined as the study of the inter-relationship between living organisms and the environment. It is the study of how organisms interact with each other and their surroundings, including both living and non-living components of the environment. Ecology is a broad field that encompasses many different areas of study, including the study of populations, communities, ecosystems, and biomes. Ecologists examine the ways in which living organisms interact with each other and with their physical and chemical environment, as well as the ways in which human activities can impact these interactions. By understanding the relationships between organisms and their environment, ecologists can develop strategies for conservation, management, and restoration of ecosystems. For example, ecologists can study the impacts of climate change on ecosystems, and develop plans to mitigate these impacts and help protect the biodiversity of our planet. So, the correct answer is "the inter-relationship between living organisms and the environment."

Détails de la réponse

Secreting irritating fluid is a behavioural adaptation that keep/protects preys from predators.

Détails de la réponse

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".

Détails de la réponse

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.

Détails de la réponse

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.

Détails de la réponse

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.

Détails de la réponse

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

Détails de la réponse

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."

Détails de la réponse

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.

Détails de la réponse

Mutation is the change in the genetic make up of an organism, which results in a new inheritable characteristic. Simply put, a mutation is a change in an organism's DNA that can be passed down to future generations. Mutations can happen naturally or can be caused by environmental factors such as exposure to radiation or chemicals. These changes can result in a variety of effects, from a simple alteration in an organism's appearance to a serious medical condition.

Détails de la réponse

It is found in moist environment because of its adaptive features.

Détails de la réponse

The movement of blood between the heart and all other parts of the body beside the lungs is called systemic circulation. In the systemic circulation, oxygenated blood flows from the heart to the body's organs and tissues, providing them with the oxygen and nutrients they need to function properly. After the oxygen has been used up by the cells, the blood carrying carbon dioxide and other waste products is then transported back to the heart to be pumped to the lungs, where it will be oxygenated again in the pulmonary circulation. The systemic circulation is a critical part of the body's overall circulatory system, which also includes the pulmonary circulation. Together, these two systems help to ensure that every part of the body has a constant supply of oxygen and nutrients and that waste products are efficiently removed from the body.

Détails de la réponse

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.

Détails de la réponse

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.

Détails de la réponse

Thunderstorms can be beneficial to plants because they add nitrogen to the soil. Lightning is an electrical discharge that can break apart nitrogen molecules in the air, and the resulting nitrogen compounds can fall to the ground in rainwater. Plants need nitrogen to grow, and thunderstorms can provide a natural source of this essential nutrient. However, it's important to note that while thunderstorms can bring benefits, they can also bring harm in the form of lightning strikes and flooding, so it's important to take necessary precautions to protect yourself and your property during severe weather.

Détails de la réponse

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.

Détails de la réponse

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.

Détails de la réponse

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.