JAMB UTME - Biology - 2018

Spectacles with convex lenses correct long-sightedness by

Antwortdetails

Spectacles with convex lenses correct long-sightedness by converging the light rays before they enter the eye. In long-sightedness, also known as hyperopia, the eyeball is too short, which causes light to focus behind the retina instead of directly on it. This results in blurry vision, especially when looking at close objects. Convex lenses are thicker in the middle and thinner at the edges, and they bend light rays towards each other. When a person with long-sightedness wears spectacles with convex lenses, the lenses converge the light rays before they enter the eye, which compensates for the shortness of the eyeball. This causes the light rays to focus directly on the retina, which results in clearer vision. Therefore, by converging the light rays before they enter the eye, convex lenses correct long-sightedness.

Tikka disease is related with the crop

Antwortdetails

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.

The hormones secreted by pancreas serves to

Antwortdetails

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

Total salt content in blood is about

Antwortdetails

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.

Study the diagram of a food chain shown and use it to answer the question.

P ---> Q ---> R ---> S ---> T

Which of the following statements best describes the organism designated R? It

Antwortdetails

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.

The reason why hospitals use saline solutions as drip instead of water is

Antwortdetails

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).

Cytokinesis of mitosis is a process that ensures that

Antwortdetails

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.

Study the diagram of a food chain shown and use it to answer the question.

P ---> Q ---> R ---> S ---> T

The organism designated P in the food chain above is normally sustained by energy from

Antwortdetails

The organism designated P in the food chain is normally sustained by energy from the sun. This is because P is likely at the bottom of the food chain, which means it is a primary producer. Primary producers, such as green plants, use energy from the sun to produce their own food through photosynthesis. This food is then consumed by the next organism in the food chain, which is Q. The energy then passes from one organism to the next, all the way up the food chain to the top predator. Therefore, in this food chain, P is likely a green plant or another type of primary producer that uses energy from the sun to produce its own food, making sunlight the source of energy for P.

A distinguishing feature of mammals is the possession of

Antwortdetails

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.

An accurate identification of a rapist can be carried out by conducting

Antwortdetails

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.

A group of closely related organisms capable of interbreeding to produce the fertile offspring are known as members of a

Antwortdetails

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.

The vessel carrying oxygenated blood to the tissues is

Antwortdetails

The vessel carrying oxygenated blood to the tissues is called an artery. Arteries are blood vessels that carry blood away from the heart, and they have thick, muscular walls that can withstand the high pressure of blood being pumped by the heart. The oxygenated blood that is pumped out of the left ventricle of the heart into the aorta is then distributed throughout the body via the network of arteries. Arteries branch into smaller vessels called arterioles and then into even smaller vessels called capillaries, where oxygen and nutrients are delivered to the body's tissues. So, arteries play a crucial role in ensuring that oxygenated blood is delivered to the body's tissues to support their proper functioning.

In the egg of a bird, the embryo is located in the

Antwortdetails

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.

The gland that is present close to Trachea

Antwortdetails

The gland that is present close to the trachea is the thyroid gland. The thyroid gland is a small, butterfly-shaped gland located in the neck, just below the Adam's apple and above the collarbone. It wraps around the front of the trachea, which is the tube that carries air to the lungs. The thyroid gland produces hormones that regulate many important functions in the body, including metabolism, growth, and development. When the thyroid gland is not working properly, it can cause a variety of health problems, including weight gain or loss, fatigue, and mood changes.

What would happen if solution Y is more concentrated than solution X in fig 2?

Antwortdetails

Osmosis is the spontaneous net movement of solvent molecules through a selectively permeable membrane into a region of higher solute concentration, in the direction that tends to equalize the solute concentrations on the two sides.

Use the diagram shown to answer the question. In plant cells, the role of the membrane is played by the

Antwortdetails

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.

What is the function of contractile vacuole in paramecium?

Antwortdetails

The contractile vacuole in paramecium functions to get rid of excess water. Paramecium is a single-celled organism that lives in freshwater environments. As water enters the cell by osmosis, the contractile vacuole collects and pumps out the excess water to prevent the cell from swelling and potentially bursting. The contractile vacuole acts like a pump, contracting and releasing to expel the excess water out of the cell. This process helps maintain the proper balance of water and ions inside the cell, which is necessary for the organism's survival. Therefore, the function of the contractile vacuole in paramecium is to regulate water balance and prevent the cell from bursting due to excess water intake.

The hygrometer is used for measuring

Antwortdetails

A hygrometer is an instrument used to measure the amount of humidity and water vapor in the atmosphere, in soil, or in confined spaces. Humidity measurement instruments usually rely on measurements of some other quantity such as temperature, pressure, mass, a mechanical or electrical change in a substance as moisture is absorbed. By calibration and calculation, these measured quantities can lead to a measurement of humidity.

A boy who is fond of swimming in a pond finds himself passing urine with traces of blood. He is likely to have contracted

Antwortdetails

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.

At which stage in this cycle can a man be infected?

Antwortdetails

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.

Long neck in giraffe is used to illustrate the theory of

Antwortdetails

The giraffe's long neck is a perfect adaptation to the animal's natural habitat. Clearly the giraffe evolved this uncommon and helpful trait in order to reach those nourishing leaves. That's how natural selection works. Use and disuse' theory in human life advocate the idea that animals acquired characteristics after using certain physical traits constantly.

Which of the following structures is not a skeletal material?

Antwortdetails

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.

The flippers of a whale and the fins of a fish are examples of

Antwortdetails

The flippers of a whale and the fins of a fish are examples of convergent evolution. Convergent evolution is a process where species that are not closely related, but live in similar environments, evolve similar structures or adaptations to solve similar problems. This is also known as "parallel evolution". For example, whales and fish both live in water, and both need to be able to swim and maneuver. Over time, both species have evolved flippers or fins as a solution to these challenges, even though whales are mammals and fish are fish. This convergence of similar structures in unrelated species is a result of convergent evolution.

The reason why the flow of blood through the capillaries is very slow is

Antwortdetails

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.

The immediate product of meiosis in flowering plants is the

Antwortdetails

Pollen grains form in the two pollen sacs located in the anther. Each pollen sac contains specialized chambers in which the microspore mother cells are enclosed and protected. The microspore mother cells undergo meiosis to form four haploid microspores. Subsequently, mitotic divisions form four pollen grains. Inside each pollen grain is a generative cell; this cell will later divide to produce two sperm cells. Pollen grain shapes are specialized for specific flower species.

What is the critical limiting factor for plants below the photic zone in an aquatic ecosystem?

Antwortdetails

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.

The cytoplasm of a cell is considered a very important component because it

Antwortdetails

The jelly-like fluid that fills a cell is called cytoplasm. It is made up of mostly water and salt. Cytoplasm is present within the cell membrane of all cell types and contains all organelles and cell parts. Cytoplasm has various functions in the cell.
Most of the important activities of the cell occur in the cytoplasm. Cytoplasm contains molecules such as enzymes which are responsible for breaking down waste and also aid in metabolic activity.

An example of a radially symmetrical organisms is

Antwortdetails

An example of a radially symmetrical organism is Hydra. Radial symmetry means that an organism has a circular shape and its body parts are arranged around a central axis, like the spokes on a wheel. Hydra is a small, freshwater animal that has a cylindrical body and tentacles that radiate out from its central axis. This type of symmetry allows Hydra to detect and capture prey from all directions. Planaria are also radially symmetrical flatworms, while tapeworms and roundworms are examples of organisms with bilateral symmetry, meaning that they have a distinct front and back and a left and right side.

A man who is heterozygous for the disease haemophilia marries a woman who is double recessive for haemophilia. What percentage of their offspring would have the disease?

Antwortdetails

Haemophilia is an X-linked recessive genetic disorder. This means that the gene responsible for haemophilia is located on the X chromosome, and individuals with two copies of the defective gene (one inherited from each parent) will have the disease. The man in this scenario is heterozygous, meaning he has one normal X chromosome and one X chromosome with the defective gene. The woman is double recessive, meaning she has two copies of the defective gene. When the man and woman have offspring, each child will inherit one of their father's X chromosomes and one of their mother's X chromosomes. The possible combinations of X chromosomes the children could inherit are: - Normal X chromosome from the father and normal X chromosome from the mother - Normal X chromosome from the father and defective X chromosome from the mother - Defective X chromosome from the father and normal X chromosome from the mother - Defective X chromosome from the father and defective X chromosome from the mother Of these possible combinations, only the last one (defective X chromosome from both parents) will result in the child having haemophilia. The probability of a child inheriting a defective X chromosome from the father is 50%, since the father is heterozygous. The probability of a child inheriting a defective X chromosome from the mother is 100%, since the mother is double recessive. Therefore, the probability of a child inheriting a defective X chromosome from both parents and having haemophilia is 50% x 100% = 50%. So the correct answer is: 50% of their offspring would have the disease.

Accessory material in a chicken egg include the following except

Antwortdetails

The accessory materials found in a chicken egg include the albumen (the egg white), the shell membrane (the thin membrane that lines the inside of the eggshell), and the shell itself. The germinal disc, on the other hand, is not an accessory material, but rather an important part of the egg. The germinal disc, also known as the blastoderm, is a small, round spot on the surface of the yolk that contains the genetic material necessary for the development of the embryo. It is located on the surface of the yolk and can be seen as a small white spot when you crack open an egg. This is where the sperm enters and fertilizes the egg, leading to the development of the embryo. So to summarize, the accessory materials found in a chicken egg are the albumen, shell membrane, and shell, while the germinal disc is an essential part of the egg that is responsible for the development of the embryo.

Red blood cells were found to have burst open after being placed in distill for an hour. This phenomenon is known as

Antwortdetails

The phenomenon you're referring to is called haemolysis. Haemolysis is the bursting of red blood cells when they are placed in a solution that is different from their normal environment. When red blood cells are placed in distilled water, the water moves into the cells and causes them to expand and eventually burst, resulting in haemolysis. This occurs because the concentration of solutes (e.g. salts, sugars) is higher inside the red blood cells than in the distilled water, causing water to move into the cells and causing them to burst. In simple terms, haemolysis is the bursting of red blood cells due to a change in the solution they are in.

How many days does it take for incubation of an egg to release chick?

Antwortdetails

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.

The overall reaction in glycolysis can be summarised as

Antwortdetails

A plant tissue that carries water and mineral salt is

Antwortdetails

The plant tissue that carries water and mineral salts from the roots to other parts of the plant is called xylem. Xylem is like a pipeline that runs throughout the plant and is responsible for transporting water and dissolved nutrients from the roots to the leaves and other parts of the plant. This tissue is made up of specialized cells called tracheids and vessel elements that are arranged end to end to form long, hollow tubes. These tubes allow water to flow through them with minimal resistance, and the water is pulled up through the xylem by a process called transpiration. In summary, xylem is the tissue responsible for carrying water and mineral salts from the roots to the rest of the plant, and it does so through a network of specialized cells that form long, hollow tubes.

Swollen, bleeding gums are another common sign of which vitamin?

Antwortdetails

The vitamin that is commonly associated with swollen, bleeding gums is Vitamin C. Vitamin C is an essential nutrient that helps in the formation of collagen, which is an important component of connective tissues like gums. Without enough Vitamin C, the collagen fibers in gums can weaken and break down, leading to inflammation, bleeding, and even tooth loss. In addition, Vitamin C has antioxidant properties that can help to protect the gums from damage caused by harmful free radicals. Therefore, a diet deficient in Vitamin C can cause gums to become swollen, inflamed, and bleed easily. Consuming sufficient amounts of Vitamin C can help to prevent and treat these symptoms, which is why it is important to include Vitamin C-rich foods in your diet, such as citrus fruits, berries, kiwi, broccoli, and peppers, among others.

\

Use the diagram shown to answer the question. After an hour, the level of water in the thistle funnel will

Antwortdetails

Which of the following relationship involves only one organism?

Antwortdetails

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.

The process in which plant uses sunlight to synthesize nutrients from carbon dioxide and water is called

Antwortdetails

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.

A pollutant that is mostly associated with acid rain is

Antwortdetails

The pollutant that is mostly associated with acid rain is nitrogen (IV) oxide, also known as nitrogen dioxide (NO2). NO2 is produced when fuels such as coal, oil, and gas are burned at high temperatures, particularly in vehicles and power plants. It is a gas that can react with other chemicals in the atmosphere to form nitric acid (HNO3), which can then fall to the ground as acid rain. When acid rain falls on soil, it can lower the pH and make it more acidic. This can have negative effects on plants and animals that live in the soil, as well as on the quality of the water in lakes and streams. In addition, acid rain can corrode buildings and other structures made of stone, metal, or concrete. To reduce the production of nitrogen (IV) oxide and the formation of acid rain, it is important to reduce the use of fossil fuels and to use cleaner sources of energy, such as wind, solar, and hydropower. Additionally, regulations and policies can be put in place to limit the emissions of nitrogen (IV) oxide from vehicles and power plants.

The greatest amount of energy would be obtained by the Oxidation of 100kg of

Antwortdetails

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