JAMB UTME - Biology - 2018
Question 1 Report
The graph below shows the results of a laboratory investigation which measured the body temperatures of a lizard and a bird under changing artificial conditions. Use it to answer the question.
What physiological term can used to describe the regulation of the body temperature of the of the lizard?
Answer Details
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".
Question 2 Report
Name the blood cells in which nucleus is absent
Answer Details
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.
Question 3 Report
Which of the following animals is cold blooded?
Answer Details
Reptiles are cold-blooded animals. This means that they cannot produce heat in their own bodies, and have to rely on their surroundings to keep warm. This is why most reptiles are found in hot or warm climates. Reptiles like snakes and lizards are this type of animal. Amphibians like frogs, toads, and salamanders are, too. Fish are also cold-blooded animals.
Question 4 Report
What is the function of trichocyst in paramecium?
Answer Details
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.
Question 5 Report
A distinguishing feature of mammals is the possession of
Answer Details
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.
Question 6 Report
The part of the ear which contains nerve cells sensitive to sound vibrations is the
Answer Details
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.
Question 7 Report
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?
Answer Details
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.
Question 8 Report
Use the diagram shown to answer the question. The experiment above is used to demonstrate the process of
Answer Details
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.
Question 9 Report
Which of the following instruments is used to estimate the number of plants in a habitat?
Answer Details
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.
Question 10 Report
Which of the following statements is true about sandy soil?
Answer Details
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.
Question 11 Report
The outer membrane that covers the brain is
Answer Details
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.
Question 12 Report
The gland that is present close to Trachea
Answer Details
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.
Question 13 Report
The function of pith in plant is
Answer Details
Pith, or medulla, is a tissue in the stems of vascular plants. Pith is composed of soft, spongy parenchyma cells, which store and transport nutrients throughout the plant. In eudicots, pith is located in the center of the stem. In monocots, it extends also into flowering stems and roots.
Question 14 Report
The vessel carrying oxygenated blood to the tissues is
Answer Details
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.
Question 15 Report
Double fertilisation is a unique features of
Answer Details
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.
Question 17 Report
The hormones secreted by pancreas serves to
Answer Details
The production of pancreatic hormones, including insulin, somatostatin, gastrin, and glucagon, play an important role in maintaining sugar and salt balance in our bodies.
Question 18 Report
Examples of animals with mammary glands include the following except
Answer Details
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.
Question 19 Report
Etiolation is causes by the influence of
Answer Details
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.
Question 20 Report
The greatest amount of energy would be obtained by the Oxidation of 100kg of
Answer Details
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
Question 21 Report
The cytoplasm of a cell is considered a very important component because it
Answer Details
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.
Question 22 Report
Which of the following is a mixed gland?
Answer Details
A mixed gland is a gland that is both exocrine and endocrine, for example, the pancreas. Pancreas is known as a mixed gland because it performs functions of both exocrine and endocrine glands.
Question 23 Report
Blood circulation in a mammal is said to be double because
Answer Details
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.
Question 24 Report
Which of the following cycles involves the process of precipitation and transpiration?
Answer Details
The cycle that involves the process of precipitation and transpiration is the water cycle. The water cycle is the process by which water circulates through the Earth's environment. It starts with the evaporation of water from bodies of water, such as oceans, lakes, and rivers, as well as from the soil and plants through a process called transpiration. This water vapor then rises into the atmosphere, where it cools and condenses into clouds. When these clouds become heavy enough, the water falls back to Earth as precipitation, which can take the form of rain, snow, sleet, or hail. Once the precipitation falls to the ground, it can either be absorbed by the soil and become groundwater or run off into bodies of water. From there, the cycle starts again. In summary, the water cycle involves the process of precipitation, which is the falling of water from the atmosphere to the Earth's surface, as well as the process of transpiration, which is the release of water vapor from plants. This cycle is essential for providing fresh water to living things and maintaining the Earth's environment.
Question 25 Report
The damage to ozone layer is caused by
Answer Details
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.
Question 26 Report
Maltose is combination of glucose and
Answer Details
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.
Question 27 Report
Which of the following diseases is not hereditary?
Answer Details
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.
Question 28 Report
Long neck in giraffe is used to illustrate the theory of
Answer Details
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.
Question 29 Report
Mineral salts can be absorbed into roots by
Answer Details
In plants and animals, mineral absorption, also called mineral uptake is the way in which minerals enter the cellular material, typically following the same pathway as water. In plants, the entrance portal for mineral uptake is usually through the roots by a process of diffusion and active transport.
Question 30 Report
A group of closely related organisms capable of interbreeding to produce the fertile offspring are known as members of a
Answer Details
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.
Question 31 Report
The temporary union of two organisms and the exchange of micronuclear elements is called
Answer Details
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.
Question 32 Report
An example of a radially symmetrical organisms is
Answer Details
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.
Question 33 Report
DNA in eukaryotic cells is contained in the
Answer Details
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.
Question 34 Report
Swollen, bleeding gums are another common sign of which vitamin?
Answer Details
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.
Question 35 Report
A plant tissue that carries water and mineral salt is
Answer Details
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.
Question 36 Report
The curvature movement of plants in response to the stimulus of water is called
Answer Details
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.
Question 37 Report
Which of the following relationship involves only one organism?
Answer Details
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.
Question 38 Report
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
Answer Details
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.
Question 39 Report
Man can contact tapeworm through
Answer Details
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.
Question 40 Report
Which is an animal without red blood cells?
Answer Details
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.
