JAMB UTME - Biology - 2018

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Saprophytism is the ability of certain plants to live in dead or decaying organic matter. A saprophyte or saprotroph is an organism which gets its energy from dead and decaying organic matter. This may be decaying pieces of plants or animals. This means that saprophytes are heterotrophs. They are consumers in the food chain.

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Aestivation is a state of animal dormancy, similar to hibernation, although taking place in the summer rather than the winter. Aestivation is characterized by inactivity and a lowered metabolic rate, that is entered in response to high temperatures and arid conditions.

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The outer membrane that covers the brain is called the "dura mater". It is a thick, tough, and fibrous layer that provides protection and support to the brain. The dura mater is the outermost layer of the three meninges (the protective membranes that surround the brain and spinal cord). It lies closest to the skull and forms a barrier that separates the brain from the bones of the skull. The dura mater contains blood vessels and nerves that supply the brain and is responsible for anchoring the brain in place.

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Cytokinesis is the final stage of mitosis, the process by which a cell divides to form two identical daughter cells. During cytokinesis, the cytoplasm of the original cell is divided into two parts, with each part containing a complete set of genetic material (chromosomes). The main purpose of cytokinesis is to ensure that each daughter cell receives a complete set of genetic material and the necessary organelles to function properly. This is important because if one daughter cell received more genetic material or more organelles than the other, it could lead to problems such as cell death or mutations. Therefore, "each daughter cell gets the necessary organelles" is the correct label to associate with the question above. While the other options may be important aspects of mitosis, they do not directly relate to the role of cytokinesis in ensuring that each daughter cell receives a complete and functional set of genetic material and organelles.

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The incubation period for chicken eggs is generally 21 days. This means that after a fertilized egg is laid by a hen and is kept at the appropriate temperature and humidity in an incubator, it will take approximately 21 days for the chick to develop and hatch out of the eggshell. During this period, the egg goes through several stages of development. In the first week, the embryo's circulatory system, nervous system, and digestive system start to form. In the second week, the chick's beak, wings, and claws begin to develop. And in the third week, the chick grows rapidly and prepares to break through the shell using its egg tooth, a small point on its beak. It's important to note that the incubation period can vary slightly depending on factors such as the breed of chicken and the temperature and humidity in the incubator. However, 21 days is the average incubation period for chicken eggs.

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The breeding posture illustrated in the diagram is known as "amplexus". Amplexus is a mating behavior displayed by many amphibians, in which the male grasps the female with his front legs from behind and holds her in position during mating. This position helps the male to fertilize the eggs as they are laid by the female. Amplexus can be further classified into two types: axillary amplexus, in which the male grasps the female's body just behind the front legs, and inguinal amplexus, in which the male grasps the female's body in the pelvic region. This behavior is critical for the reproduction of many amphibian species, and without it, successful fertilization of the eggs would be less likely to occur.

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The total salt content in blood is about 0.85 to 0.9%. Salt, which is also known as sodium chloride, is an essential mineral that is necessary for many bodily functions such as maintaining fluid balance, transmitting nerve impulses, and contracting muscles. However, too much salt in the blood can lead to health problems like high blood pressure, so it's important to maintain a proper balance. The normal range for salt content in the blood is typically around 0.9%, which is equivalent to 9 grams of salt per liter of blood.

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While humans and many other species have red blood, due to the iron in their hemoglobin, other animals have different colored blood. Spiders (as well as horseshoe crabs and certain other arthropods) have blue blood due to the presence of copper-based hemocyanin in their blood. Some animals, such as the sea cucumbers, even have yellow blood. What could make blood yellow? The yellow coloration is due to a high concentration of the yellow vanadium-based pigment, vanabin. Unlike hemoglobin and hemocyanin, vanabin does not seem to be involved in oxygen transport.

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Special temporary organs or embryonic membranes form within the egg, both to protect the embryo and to provide for its nutrition, respiration, and excretion. These organs include the yolk sac. The yolk sac is also responsible for the initial circulation and is in charge of delivering nutrients, via a primitive aorta, to the developing embryo through a process called vitelline circulation.

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The arteries are the blood vessels that deliver oxygen-rich blood from the heart to the tissues of the body. Each artery is a muscular tube lined by smooth tissue and has three layers: The intima, the inner layer lined by a smooth tissue called endothelium. Arteries have smaller lumens than veins, a characteristic that helps to maintain the pressure of blood moving through the system. They carry blood away from the heart. Pulmonary arteries transport blood that has a low oxygen content from the right ventricle to the lungs. Arteries do not possess valves at intervals throughout their length

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In the animal's intestine, the oncospheres hatch, invade the intestinal wall, and migrate to the striated muscles, where they develop into cysticerci. A cysticercus can survive for several years in the animal. Humans become infected by ingesting raw or undercooked infected meat.

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The rate, or velocity, of blood flow varies inversely with the total cross-sectional area of the blood vessels. As the total cross-sectional area of the vessels increases, the velocity of flow decreases. Blood flow is slowest in the capillaries, which allows time for exchange of gases and nutrients. Flow is slowest in the capillaries because of their larger cross-sectional area and narrow diameter.

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The correct answer is "species". Species are a group of living organisms that share common characteristics and can interbreed to produce fertile offspring. This means that members of the same species can mate and produce offspring that can themselves reproduce, while organisms from different species cannot produce fertile offspring together. For example, dogs can breed with other dogs to produce fertile puppies, but they cannot breed with cats to produce offspring that can reproduce. Therefore, dogs and cats belong to different species.

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DNA in eukaryotic cells is contained in the nucleus. The nucleus is a membrane-bound structure found in eukaryotic cells that acts as the "brain" of the cell, controlling and regulating all of its functions. It is also where the cell's DNA is stored and protected, in a substance called chromatin. The DNA in the chromatin is organized into long structures called chromosomes, which are visible during cell division. In short, the nucleus is the place where the DNA of a eukaryotic cell is located and it plays a vital role in the functioning of the cell.

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Bone is the substance that forms the skeleton of the body. It is composed chiefly of calcium phosphate and calcium carbonate. Chitin is a major constituent of the exoskeleton, or external skeleton, of many arthropods such as insects, spiders, and crustaceans. The main structural components of our bodies are bone, muscle, and cartilage. Bones are rigid, while muscles bend, stretch, and are flexible. Cartilage connective tissue is the perfect halfway point between these other tissues. It is not as rigid or as hard as bone, and it is also less flexible than muscle. Therefore, we find cartilage in places where we need some support and structure, but a bit of flexibility as well. This includes places such as our joints, our ears, and our nose, as well as in between the vertebrae in our spinal column.

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Primary consumers eat these plants exclusively and are all herbivores. We defined secondary consumers as organisms, primarily animals, which eat primary consumers. Furthermore, secondary consumers can be classified into one of two groups: carnivores, or meat eaters, and omnivores, which are plant and meat eaters.

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An adult tapeworm consists of a knoblike head, or scolex, equipped with hooks for attaching to the intestinal wall of the host (which may be a human), a neck region, and a series of flat, rectangular body segments, or proglottids, generated by the neck. Scolex is used for attachment to the intestinal wall.

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Blood plasma is a yellowish liquid component of blood that normally holds the blood cells in whole blood in suspension. In other words, it is the liquid part of the blood that carries cells and proteins throughout the body. It makes up about 55% of the body's total blood volume.

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Scabies is the disease that is not hereditary. Scabies is a skin infestation caused by a tiny mite called Sarcoptes scabiei. It spreads through direct skin-to-skin contact with an infected person. Scabies is not a genetic disorder and does not pass down from parent to child through genes. It is caused by a microscopic organism that can infect anyone who comes into contact with it. On the other hand, Albinism, Haemophilia, and Color blindness are all hereditary diseases. Albinism is a genetic condition that affects the production of melanin, resulting in little or no pigment in the skin, hair, and eyes. Haemophilia is a genetic disorder that affects the blood's ability to clot properly. Color blindness is a genetic condition that affects the ability to distinguish between different colors. In summary, while Scabies is caused by a tiny mite and is not hereditary, Albinism, Haemophilia, and Color blindness are all genetic conditions that are inherited from one's parents.

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One distinguishing feature of mammals is the possession of hair. Hair is a unique type of structure that grows from the skin of mammals and is made up of a protein called keratin. Hair serves many important functions in mammals, such as keeping the body warm, protecting the skin from damage, and providing sensory information. Hair can also be used for social communication, such as when a cat raises its fur to make itself look bigger and more intimidating. While other animals like reptiles may have scales, and birds may have feathers, only mammals have hair as a defining feature.

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The role of the membrane in plant cells is played by the cell wall. The cell wall is a protective outer layer that surrounds the plasma membrane, which is a thin layer that encloses the cytoplasm and other cell structures. The cell wall provides support and structure to the cell, and also helps to maintain the shape of the cell. The nucleolus is a structure within the nucleus of a cell that is involved in the production of ribosomes, while the cytoplasm is the gel-like substance that fills the interior of a cell and contains all of the cell's organelles. The mitochondrion is an organelle within the cytoplasm that is responsible for generating energy for the cell.

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Saline, also known as saline solution, is a mixture of sodium chloride in water and has a number of uses in medicine. Intravenous therapy (IV) is a therapy that delivers liquid substances directly into a vein. Saline is used in I.V. therapy, intravenously supplying extra water to rehydrate patients or supplying the daily water and salt needs ("maintenance" needs) of a patient who is unable to take them by mouth. Because infusing a solution of low osmolality can cause problems such as hemolysis, intravenous solutions with reduced saline concentrations typically have dextrose (glucose) added to maintain a safe osmolality while providing less sodium chloride. The amount of normal saline infused depends largely on the needs of the patient (e.g. ongoing diarrhea or heart failure).

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To determine which of the given food items provides the greatest amount of energy upon oxidation, we need to compare their caloric content. Here's a general overview of the approximate caloric values per 100 grams for each type of food:

• Meat: Approximately 250 calories (varies depending on the type and cut of meat)
• Butter: Approximately 717 calories
• Sugar: Approximately 387 calories
• Biscuits: Approximately 450 calories (varies depending on ingredients and recipe)

Now, let's scale these values up to 100 kg (100,000 grams):

• Meat: $\mathrm{<span\; style="font-family:\; Ubuntu;">250</span>}\text{<span style="font-family: Ubuntu;">\hspace{0.17em}</span>}\text{<span style="font-family: Ubuntu;">calories/100g</span>}<span\; style="font-family:\; Ubuntu;">\times </span>\mathrm{<span\; style="font-family:\; Ubuntu;">1000</span>}<span\; style="font-family:\; Ubuntu;">=</span>\mathrm{<span\; style="font-family:\; Ubuntu;">250</span>}<span\; style="font-family:\; Ubuntu;">,</span>\mathrm{<span\; style="font-family:\; Ubuntu;">000</span>}\text{<span style="font-family: Ubuntu;">\hspace{0.17em}</span>}\text{<span style="font-family: Ubuntu;">calories</span>}$250 \, \text{calories/100g} \times 1000 = 250,000 \, \text{calories}
• Butter: $717\text{calories/100g}\times 1000=717,000\text{calories}717\; \backslash ,\; \backslash text\{calories/100g\}\; \backslash times\; 1000\; =\; 717,000\; \backslash ,\; \backslash text\{calories\}$
• Sugar: $387\text{calories/100g}\times 1000=387,000\text{calories}387\; \backslash ,\; \backslash text\{calories/100g\}\; \backslash times\; 1000\; =\; 387,000\; \backslash ,\; \backslash text\{calories\}$
• Biscuits: $450\text{calories/100g}\times 1000=450,000\text{calories}450\; \backslash ,\; \backslash text\{calories/100g\}\; \backslash times\; 1000\; =\; 450,000\; \backslash ,\; \backslash text\{calories\}$

From these calculations, butter has the highest caloric content per 100 kg. Therefore, the greatest amount of energy will be obtained by the oxidation of 100 kg of:

B. butter

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The part of the ear which contains nerve cells sensitive to sound vibrations is the cochlea. The cochlea is a small, spiral-shaped structure in the inner ear. It is responsible for translating sound waves into electrical signals that can be interpreted by the brain. The cochlea contains tiny hair cells that are responsible for detecting sound vibrations. These hair cells are arranged along the length of the cochlea and are stimulated by different frequencies of sound. When sound waves enter the ear, they cause the eardrum to vibrate. These vibrations are then transmitted to the three small bones in the middle ear, including the malleus. The malleus transmits the vibrations to the inner ear, where they are picked up by the hair cells in the cochlea. The hair cells then convert the vibrations into electrical signals that are transmitted to the brain via the auditory nerve, allowing us to hear and interpret sounds. In summary, the cochlea is the part of the ear that contains nerve cells sensitive to sound vibrations. The hair cells within the cochlea are responsible for detecting sound waves and translating them into electrical signals that can be interpreted by the brain.

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The process in which plants use sunlight to synthesize nutrients from carbon dioxide and water is called photosynthesis. Photosynthesis is a crucial process that enables plants to produce their own food and is responsible for releasing oxygen into the atmosphere. During photosynthesis, plants use chlorophyll, a pigment found in their leaves and other green parts, to capture energy from sunlight. This energy is used to combine carbon dioxide and water to produce glucose (a type of sugar) and oxygen. The glucose produced is then used by the plant as an energy source to fuel its growth and other metabolic processes. In summary, photosynthesis is the process by which plants convert sunlight into chemical energy, which they use to synthesize nutrients and sustain their growth and survival.

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Tikka disease is not related to the crop of Groundnut, Mustard, or Paddy. Tikka disease, also known as Ascochyta blight, is a fungal disease that affects various plants, including beans, chickpeas, and lentils. The disease is caused by a fungus called Ascochyta and can result in small, circular spots on leaves, stems, and pods of infected plants. These spots can be gray, brown, or black, and may have a dark border. In summary, Tikka disease is not related to the crops of Groundnut, Mustard, or Paddy. It affects plants such as beans, chickpeas, and lentils, and is caused by a fungus called Ascochyta.

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Primary production in the photic zone is influenced by three major factors—nutrients and light, which are essential for photosynthesis, and grazing pressure, the rate at which the plants are eaten by herbivores.

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An accurate identification of a rapist can be carried out by conducting DNA analysis. DNA analysis involves collecting and analyzing a sample of DNA from a suspect, such as a hair, skin, or semen sample, and comparing it to a sample of DNA taken from the crime scene. If the DNA profiles match, it can provide strong evidence linking the suspect to the crime. Blood group tests and behavioral tests are not reliable methods for identifying a rapist, as they do not provide a unique identifier like DNA analysis does. Additionally, RNA analysis is not typically used for the identification of rapists. DNA analysis is the most scientifically accepted and accurate method for identifying individuals in criminal investigations, including sexual assault cases.

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Ozone sits in the upper atmosphere and absorbs ultraviolet radiaton, another type of solar energy that's harmful to humans, animals and plants. CFCs and halons cause chemical reactions that break down ozone molecules, reducing ozone's ultraviolet radiation-absorbing capacity. Chlorofluorocarbons (CFCs) and other halogenated ozone depleting substances (ODS) are mainly responsible for man-made chemical ozone depletion.

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Maltose is a disaccharide, which means it is made up of two simple sugar molecules. Specifically, maltose is made up of two glucose molecules that are joined together by a type of bond called a glycosidic bond. Glucose is a monosaccharide, which means it is a simple sugar that cannot be broken down into any simpler sugars. Maltose is formed when two glucose molecules are linked together by a glycosidic bond. This bond is formed by the removal of a molecule of water between the two glucose molecules. The resulting molecule of maltose is therefore a combination of two glucose molecules. Sucrose, on the other hand, is a different type of disaccharide that is made up of one glucose molecule and one fructose molecule, while galactose is a monosaccharide that can combine with glucose to form lactose, a disaccharide found in milk. So to summarize, maltose is a disaccharide made up of two glucose molecules that are linked together by a glycosidic bond. It is not made up of fructose, sucrose, or galactose.

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Etiolation is caused by the influence of LIGHT. Etiolation refers to the physical changes that occur in a plant when it is grown in the absence of sufficient light. When a plant does not receive enough light, it elongates its stem and leaves to reach for the light source. This results in a spindly, pale appearance, as the plant allocates its resources towards vertical growth rather than producing chlorophyll and other pigments needed for photosynthesis. Therefore, the absence of light, or insufficient light, is the primary cause of etiolation. While mineral salts, water, and carbon dioxide are all necessary for plant growth, they do not directly cause etiolation.

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The production of pancreatic hormones, including insulin, somatostatin, gastrin, and glucagon, play an important role in maintaining sugar and salt balance in our bodies.

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The curvature movement of plants in response to the stimulus of water is called "hydrotropism." Hydrotropism is a type of plant movement that occurs when a plant's roots grow towards a source of water. This is an important mechanism that allows plants to find water and nutrients in the soil. When a plant is exposed to a source of water, such as a moist patch of soil, the plant's roots will start to grow towards the water. This is because the cells on the side of the root closest to the water absorb more water and expand, causing the root to bend towards the source of water. As the root grows towards the water, it will continue to bend until it reaches the water source. Hydrotropism is different from other types of plant movements, such as geotropism, phototropism, and thigmotropism, which involve responses to gravity, light, and touch, respectively.

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The physiological term that can be used to describe the regulation of the body temperature of the lizard is "poikilothermy". Poikilothermy refers to the ability of an animal's body temperature to fluctuate with changes in the external environment. In other words, the body temperature of poikilothermic animals, such as lizards, is not actively regulated by their bodies, but rather is influenced by the temperature of their surroundings. As seen in the graph, the body temperature of the lizard varies with the temperature of the environment it is in. This is in contrast to homeothermic animals, such as birds and mammals, which can maintain a relatively constant body temperature regardless of external temperature changes through the process of "thermoregulation".

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The group of organisms that have kidneys as the excretory organ is: fishes, amphibians, birds, and man. Kidneys are specialized organs that remove waste products, excess water, and other impurities from the blood. These waste products are then eliminated from the body as urine. Fishes, amphibians, birds, and mammals (including humans) all have kidneys as their primary excretory organ. In fish, the kidneys are responsible for removing excess water and electrolytes from the blood. In amphibians, the kidneys also play a role in maintaining water balance, as well as removing nitrogenous wastes. In birds and mammals, the kidneys are responsible for filtering the blood, regulating water and electrolyte balance, and eliminating waste products. In contrast, annelids (a group of segmented worms), insects, protozoans, reptiles, and tapeworms have different excretory organs. For example, insects have specialized structures called Malpighian tubules that remove waste products and excess water from their blood, while tapeworms excrete waste products through their skin.

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An animal that is active during the day is known as a diurnal animal. This means that it is awake and active during the daytime hours, when the sun is shining, and typically sleeps or rests during the night. Diurnal animals have evolved to take advantage of the sunlight and are often adapted to see well in bright light. Examples of diurnal animals include humans, birds, squirrels, and many species of primates.

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Cnidaria is a phylum under Kingdom Animalia containing over 11,000 species of animals found exclusively in aquatic environments: they are predominantly marine. Their distinguishing feature is cnidocytes, specialized cells that they use mainly for capturing prey. Modern cnidarians are generally classified into four main classes: sessile Anthozoa (sea anemones, corals, sea pens); swimming Scyphozoa (jellyfish) and Cubozoa (box jellies); and Hydrozoa, a diverse group that includes all the freshwater cnidarians as well as many marine forms, and has both sessile members such as Hydra and colonial swimmers such as the Portuguese Man o' War. The Turbellaria are one of the traditional sub-divisions of the phylum Platyhelminthes, and include all the sub-groups that are not exclusively parasitic.

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The boy who is fond of swimming in a pond and passes urine with traces of blood is likely to have contracted schistosomiasis. Schistosomiasis is a parasitic infection caused by a type of flatworm called Schistosoma that commonly inhabits freshwater snails and bodies of water such as ponds and lakes. When a person comes into contact with water contaminated with the parasite, it can penetrate the skin and enter the bloodstream, where it eventually travels to the bladder or intestines and causes inflammation and damage to the tissues. This can lead to symptoms such as blood in the urine or stool, abdominal pain, diarrhea, and anemia. If left untreated, schistosomiasis can lead to chronic health problems such as liver and kidney damage. Therefore, it is important to seek medical attention if experiencing symptoms after swimming or coming into contact with freshwater bodies in endemic areas.