JAMB UTME - Biology - 2018
Pergunta 1 Relatório
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?
Detalhes da Resposta
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.
Pergunta 2 Relatório
Which of the following groups of organisms has kidney as the excretory organ?
Detalhes da Resposta
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.
Pergunta 3 Relatório
The greatest amount of energy would be obtained by the Oxidation of 100kg of
Detalhes da Resposta
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: 250 \, \text{calories/100g} \times 1000 = 250,000 \, \text{calories}250calories/100g×1000=250,000calories
- Butter: 717calories/100g×1000=717,000calories
- Sugar: 387calories/100g×1000=387,000calories
- Biscuits: 450calories/100g×1000=450,000calories
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
Pergunta 4 Relatório
Which of the following instruments is used to estimate the number of plants in a habitat?
Detalhes da Resposta
The instrument used to estimate the number of plants in a habitat is a quadrant. A quadrant is a square or rectangular frame that is used to isolate a specific area within a habitat for study. It is typically made of a lightweight and durable material, such as metal or plastic, and can be any size, depending on the needs of the study. To estimate the number of plants in a habitat using a quadrant, researchers randomly select several quadrants within the study area and place them on the ground. They then count the number of plants within the quadrant and use this information to estimate the number of plants in the entire study area. Quadrants are a commonly used tool in ecology and are particularly useful for estimating the density and distribution of plant populations. They are simple to use and can provide valuable information for researchers who are interested in understanding the dynamics of plant communities.
Pergunta 5 Relatório
Which of the following features is not a characteristic of arteries? Arteries
Detalhes da Resposta
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
Pergunta 6 Relatório
Use the diagram to answer the question. The diagram shows that the organisms are
Detalhes da Resposta
Pergunta 7 Relatório
The hygrometer is used for measuring
Detalhes da Resposta
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.
Pergunta 8 Relatório
Blood circulation in a mammal is said to be double because
Detalhes da Resposta
The majority of mammals (including humans) utilize a double circulatory system. This means we have two loops in our body in which blood circulates. One is oxygenated, meaning oxygen rich, and the other is deoxygenated, which means it has little to no oxygen, but a lot of carbon dioxide.
Pergunta 9 Relatório
Evidence of evolution include the following except
Detalhes da Resposta
Note: Evolution is a process of gradual change that takes place over many generations, during which species of animals, plants, or insects slowly change some of their physical characteristics.
Pergunta 10 Relatório
How many days does it take for incubation of an egg to release chick?
Detalhes da Resposta
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.
Pergunta 11 Relatório
The temporary union of two organisms and the exchange of micronuclear elements is called
Detalhes da Resposta
The temporary union of two organisms and the exchange of micronuclear elements is called "conjugation". Conjugation is a process of sexual reproduction in some single-celled organisms, such as certain bacteria and protozoa. During conjugation, two organisms come together and form a temporary union. They exchange genetic material through a small opening that forms between them, allowing the exchange of micronuclear elements, such as DNA. The exchanged micronuclear elements contain genetic information that can be used to produce new offspring with different genetic traits from the parent organisms. This allows for increased genetic diversity within a population, which can be important for adaptation and evolution. In summary, conjugation is a process of temporary union and genetic exchange between two organisms, which can lead to increased genetic diversity within a population.
Pergunta 12 Relatório
The immediate product of meiosis in flowering plants is the
Detalhes da Resposta
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.
Pergunta 13 Relatório
Accessory material in a chicken egg include the following except
Detalhes da Resposta
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.
Pergunta 14 Relatório
A pollutant that is mostly associated with acid rain is
Detalhes da Resposta
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.
Pergunta 15 Relatório
The gland that is present close to Trachea
Detalhes da Resposta
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.
Pergunta 17 Relatório
Botany is also known as
Detalhes da Resposta
Botany is also known as "phytology". This term is derived from the Greek word "phyton", which means "plant". Phytology is the scientific study of plants, including their structure, growth, reproduction, metabolism, and classification. It involves the examination of plant anatomy, physiology, ecology, genetics, and evolution. Botanists also study the relationship between plants and their environment, including the interactions between plants and other organisms such as insects, fungi, and bacteria. Overall, phytology is an important field of study that helps us to better understand and appreciate the complexity and diversity of plant life on our planet.
Pergunta 18 Relatório
Use the diagram shown to answer the question. The experiment above is used to demonstrate the process of
Detalhes da Resposta
The experiment shown in the diagram is used to demonstrate the process of osmosis. Osmosis is the movement of water molecules across a selectively permeable membrane from an area of high water concentration to an area of low water concentration. In the experiment, the selectively permeable membrane is the potato cell membrane, and the water moves from the area of high concentration (in the beaker) to the area of low concentration (inside the potato). This causes the potato to swell and become heavier as it absorbs the water through osmosis. Thus, the experiment demonstrates the process of osmosis.
Pergunta 19 Relatório
A group of closely related organisms capable of interbreeding to produce the fertile offspring are known as members of a
Detalhes da Resposta
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.
Pergunta 20 Relatório
The four classes of cnidarian include the following except
Detalhes da Resposta
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.
Pergunta 21 Relatório
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
Detalhes da Resposta
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.
Pergunta 22 Relatório
The longest bone in the body is the
Detalhes da Resposta
The longest bone in the body is the femur. The femur is located in the thigh region and runs from the hip joint to the knee joint. It is also the strongest bone in the body, designed to support the weight of the body and withstand the forces produced by activities such as running and jumping. The femur's length can vary depending on a person's height, with taller people generally having longer femurs. Overall, the femur plays a critical role in allowing us to walk, run, and engage in other physical activities.
Pergunta 23 Relatório
Which of the following relationship involves only one organism?
Detalhes da Resposta
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.
Pergunta 24 Relatório
Which of the following structures is not a skeletal material?
Detalhes da Resposta
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.
Pergunta 25 Relatório
What would happen if solution Y is more concentrated than solution X in fig 2?
Detalhes da Resposta
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.
Pergunta 26 Relatório
Long neck in giraffe is used to illustrate the theory of
Detalhes da Resposta
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.
Pergunta 27 Relatório
Examples of micronutrients include the following except
Detalhes da Resposta
The essential elements can be divided into macronutrients and micronutrients. Nutrients that plants require in larger amounts are called macronutrients. About half of the essential elements are considered macronutrients: carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur.
Pergunta 28 Relatório
Examples of animals with mammary glands include the following except
Detalhes da Resposta
A mammary gland is an exocrine gland in mammals that produces milk to feed young offspring. Mammals get their name from the Latin word mamma, "breast". Hens do not have mammary glands.
Pergunta 29 Relatório
Man can contact tapeworm through
Detalhes da Resposta
Yes, a person can come into contact with tapeworms by ingesting uncooked or undercooked meat that contains tapeworm larvae. Tapeworms can infect animals such as cows, pigs, and fish, and when humans eat infected meat, they can get infected too. This is why it's important to cook meat thoroughly and to wash fruits and vegetables before eating them. Contact with tapeworms cannot occur through breathing or simple physical contact with an infected person or animal.
Pergunta 30 Relatório
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
Detalhes da Resposta
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.
Pergunta 31 Relatório
Name the blood cells in which nucleus is absent
Detalhes da Resposta
Like red cells, platelets (thrombocytes) have no nucleus. However, unlike red cells that originate in the marrow as nucleated cells and lose their nucleus, platelets are produced by budding off from a giant multinucleated marrow cell called a megakaryocyte.
Pergunta 32 Relatório
A seed of a flowering plant can best be described as
Detalhes da Resposta
A seed is a small embryonic plant enclosed in a covering called the seed coat, usually with some stored food. It is the product of the ripened ovule of gymnosperm and angiosperm plants which occurs after fertilization and some growth with in the motherplant.
Pergunta 33 Relatório
The yellowish colored liquid component of blood that normally holds the blood cells in suspension is
Detalhes da Resposta
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.
Pergunta 34 Relatório
Which is an animal without red blood cells?
Detalhes da Resposta
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.
Pergunta 35 Relatório
A beaker of pond water containing few specimens of Euglena was placed in a dark room for two weeks. At the end of this period, the specimens of Euglena were still alive because they were
Detalhes da Resposta
Holozoic nutrition is a type of heterotrophic nutrition that is characterized by the internalization (ingestion) and internal processing of gaseous, liquid or solid food particles. Protozoa, such as amoebas, and most of the free living animals,such as animals, exhibit this type of nutrition.
In holozoic nutrition the energy and organic building blocks are obtained by ingesting and then digesting other organisms or pieces of other organisms, including blood and decaying organic matter. This contrasts with holophytic nutrition, in which energy and organic building blocks are obtained through photosynthesis or chemosynthesis, and with saprozoic nutrition, in which digestive enzymes are released externally and the resulting monomers (small organic molecules) are absorbed directly from the environment.
Holophytic (plant-like), holozoic (animal- like), and saprophytic nutrition is found in Euglena. Euglena obtains its carbohydrate food by photosynthesis and nitrogenous food by absorption from the surroundings. Its holozoic nutrition is, however, doubtful.
Pergunta 36 Relatório
Which of the following statements is true about sandy soil?
Detalhes da Resposta
Sandy soils are well drained. They have low water holding capacity and are therefore drought prone. They become firm when wet (the opposite of clay), and loose when dry. Sandy soil is light and easy to dig.
Pergunta 37 Relatório
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Use the diagram shown to answer the question. After an hour, the level of water in the thistle funnel will
Detalhes da Resposta
Pergunta 38 Relatório
Spectacles with convex lenses correct long-sightedness by
Detalhes da Resposta
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.
Pergunta 39 Relatório
What is the function of trichocyst in paramecium?
Detalhes da Resposta
Trichocyst, a structure in the cortex of certain ciliate and flagellate protozoans consisting of a cavity and long, thin threads that can be ejected in response to certain stimuli. Trichocysts may be widely distributed over an organism or restricted to certain areas (e.g., tentacles, papillae, around the mouth). It is also a structure in the cortex of certain ciliate and flagellate protozoans consisting of a cavity and long, thin threads that can be ejected in response to certain stimuli.
Pergunta 40 Relatório
Double fertilisation is a unique features of
Detalhes da Resposta
Double fertilization is a unique feature of angiosperms, also known as flowering plants. During double fertilization, two sperm cells from the pollen grain fertilize two different cells in the female reproductive structure of the flower. One sperm cell fertilizes the egg cell to form the zygote, which will develop into the embryo of the seed. The other sperm cell fertilizes two nuclei in the central cell, which results in the formation of a triploid cell called the endosperm. The endosperm provides nourishment to the developing embryo. This process is unique to angiosperms and is not seen in bryophytes, pteridophytes, or algae. It is one of the key factors that has contributed to the success of angiosperms, as the endosperm provides a rich source of nutrients for the developing embryo, giving it a competitive advantage for survival and growth.
