JAMB UTME - Biology - 2019

In plants, respiration occurs in

Detalhes da Resposta

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.

Trees in Savanna habitats usually have thick bark which mainly.

Detalhes da Resposta

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

Good quality food will perform the following functions in human except

Detalhes da Resposta

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.

Which of the following pairs of organisms are photosynthetic?

Detalhes da Resposta

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".

The basis of growth involves the following processes except

Detalhes da Resposta

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 is considered to be the first product of Photosynthesis?

Detalhes da Resposta

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.

The change in the genetic make up of an organism resulting in an inheritable characteristics which is new is

Detalhes da Resposta

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.

The specific portion of a habitat which is occupied by a particular species is referred to as

Detalhes da Resposta

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.

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

Detalhes da Resposta

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.

The type of nutrition shown by spirogyra is

Detalhes da Resposta

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.

Which of the following will have the least effect on the rate of change of the numbers in a population

Detalhes da Resposta

The food supply will have the least effect on the rate of change of the numbers in a population. While food supply can impact the growth and survival of a population, it is less likely to cause rapid changes in population size compared to other factors such as disease, predation, and mutation. Disease, predation, and mutation can all have significant impacts on a population by affecting the survival and reproductive success of individuals, leading to changes in the overall population size. For example, a disease outbreak can reduce the number of individuals in a population, while predation can limit the growth of a population by preying on individuals. Mutations can also impact the population by changing the genetic makeup of the population and altering its ability to survive and reproduce. In conclusion, while food supply is important for maintaining a stable population, it is less likely to cause rapid changes in population size compared to other factors such as disease, predation, and mutation.

Which of the following are components of glomerular filtrate?

Detalhes da Resposta

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 part labelled a in the above diagram is used for

Detalhes da Resposta

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

Rabbits cannot survive in an aquatic habitat because they have

Detalhes da Resposta

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.

The glomerular filtrate contains the following except

Detalhes da Resposta

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.

The study of an individual organism or a single species of organism and its environment is

Detalhes da Resposta

Artecology is the study of an individual organism or a single specie of organism and no environment

Raw materials required by green plants to manufacture their food are

Detalhes da Resposta

The raw materials required by green plants to manufacture their food are mainly inorganic substances. During photosynthesis, green plants use energy from sunlight to convert carbon dioxide from the air and water from the soil into glucose, a type of sugar that they use as food. The inorganic substances required for this process include carbon dioxide, water, and a few mineral nutrients such as nitrogen, phosphorus, and potassium, which the plants absorb from the soil through their roots. Although green plants do require fluids, such as water, and gases, such as carbon dioxide, for photosynthesis, these materials are considered inorganic because they do not contain carbon-hydrogen bonds, which are characteristic of organic molecules. Thus, the main raw materials required by green plants for photosynthesis are inorganic substances.

The male sex cells also called gametes are produced in the testes by a process called

Detalhes da Resposta

The male sex cells, also called gametes, are produced in the testes by a process called Spermatogenesis. Spermatogenesis is the process by which sperm cells are produced and mature. It begins in puberty and continues throughout a man's life. During spermatogenesis, the cells in the testes divide and differentiate into sperm cells, which are then stored in the epididymis until they are ready to be ejaculated. Sperm cells are important for fertilization and are necessary for sexual reproduction.

Which of the following is an example of discontinous variatio?

Detalhes da Resposta

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.

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

Detalhes da Resposta

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 pairs of scientists discovered the Rhesis factor in human blood?

Detalhes da Resposta

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.

The number of times an organism occurs within a given area of a habitat is referred to as

Detalhes da Resposta

Population frequency refers to the number of times an organism occurs within a given area of a habitat

Competition among individuals of a population increases the

Detalhes da Resposta

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

Detalhes da Resposta

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.

The study which involves the inter-relationship between groups of organisms or species of organisms living together in an area is

Detalhes da Resposta

The study which involves the inter-relationship between groups of organisms or species of organisms living together in an area is called synecology. Synecology is a branch of ecology that examines the interactions and relationships between different species in a given ecosystem or community. It considers the biotic and abiotic factors that affect the survival and growth of populations and how they interact with one another. This study helps us to understand the complex network of relationships between different species and how they are dependent on one another for their survival. It is important for understanding the dynamics of ecosystems and how they may change over time due to human or natural factors.

Which of the following juices contains the enzyme ptyalin?

Detalhes da Resposta

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.

One important characteristics of green plant is that they

Detalhes da Resposta

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.

The possession of chloroplast in Euglena virids enables it to

Detalhes da Resposta

The possession of chloroplast in Euglena viridis enables it to carry out photosynthesis. Photosynthesis is the process by which green plants and algae use sunlight to synthesize food (glucose) from carbon dioxide and water. Chloroplasts are organelles found in the cells of green plants and algae that contain the pigment chlorophyll, which absorbs sunlight and is essential for photosynthesis. Euglena viridis is a unicellular organism that possesses chloroplasts, which enables it to harness sunlight to produce its own food through photosynthesis. Therefore, the answer is that the possession of chloroplast in Euglena viridis enables it to carry out photosynthesis.

The organism above can be found in

Detalhes da Resposta

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

Which of the following describes the function of lymph

Detalhes da Resposta

Lymph is a fluid that circulates through the lymphatic system, which is part of the immune system. Its main function is to help defend the body against harmful substances, such as viruses and bacteria, by removing waste and debris from tissues and transporting it to the bloodstream for elimination. This makes option "Body defense" the correct answer.

A virus can sometimes be regarded as a living organism because it

Detalhes da Resposta

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.

The part labeled III in the above diagram is

Detalhes da Resposta

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.

The movement of blood between the heart and all other parts of the body beside the lungs is

Detalhes da Resposta

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.

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

Detalhes da Resposta

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.

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

Detalhes da Resposta

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.

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

Detalhes da Resposta

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".

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

Detalhes da Resposta

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.

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

Detalhes da Resposta

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.

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

Detalhes da Resposta

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

The following processes are involved during expiration in man except

Detalhes da Resposta

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.