POST UTME Unical Biology Past Questions And Answers
Which of these diseases cannot be prevented by immunization
- A) Onhcocerciasis
- B) Poliomyelitis
- C) Cholera
- D) Tuberculosissis
Correct Answer: A) Onhcocerciasis
Explanation
Immunization is a process where a person is given a vaccine to help the body build immunity against a particular disease. The question is asking which of these diseases cannot be prevented by immunization. The options are Onchocerciasis, Poliomyelitis, Cholera, and Tuberculosis. Onchocerciasis, which is also known as river blindness, is caused by a parasitic worm that is transmitted through the bites of infected blackflies. There is currently no vaccine available to prevent Onchocerciasis, so Option A is the correct answer. Poliomyelitis, also known as polio, is a highly infectious viral disease that can cause paralysis. The polio vaccine has been very effective in preventing the disease, so Option B is not the correct answer. Cholera is a bacterial disease that can cause severe diarrhea and dehydration. There is a vaccine available to prevent cholera, so Option C is not the correct answer. Tuberculosis, commonly known as TB, is a bacterial infection that affects the lungs. There is a vaccine called the BCG vaccine that can help prevent TB, although it is not always effective. Therefore, Option D is not the correct answer. In summary, the disease that cannot be prevented by immunization is Onchocerciasis, so Option A is the correct answer.
The phenomenon whereby some organisms with certain features get established in an environment is known as
- A) Partial selection
- B) Artificial selection
- C) Natural selection
- D) Mutation
Correct Answer: C) Natural selection
Explanation
The question is asking about the term used to describe when some organisms with certain features become established in an environment. This phenomenon is called natural selection. Natural selection is a process where organisms that are better adapted to their environment have a greater chance of survival and passing on their traits to their offspring. These adaptations can be physical characteristics, behaviors, or even genetic mutations. It is important to note that natural selection is a key mechanism of evolution. Over time, as organisms continue to adapt to their environment, they may evolve into new species. This process can take millions of years and is influenced by many factors such as changes in the environment and genetic variation within a population. Artificial selection, on the other hand, is when humans intentionally breed plants or animals for specific traits, such as larger fruits or a certain coat color. Partial selection is not a term used in biology and mutation refers to a change in the genetic material of an organism. In summary, the correct answer to this question is natural selection, which is the process whereby organisms that are better adapted to their environment have a greater chance of survival and passing on their traits to their offspring.
Which of the following specialized structures are stimulated by touch, pressure, pain, heat and cold?
- A) receptors
- B) synapse
- C) cell bodies
- D) myelin
Correct Answer: A) receptors
Explanation
This question is asking which specialized structures in our body are activated when we feel touch, pressure, pain, heat, and cold. The options are: A) receptors, B) synapse, C) cell bodies, and D) myelin. The correct answer is A) receptors. Receptors are specialized structures in our body that detect different types of stimuli, such as touch, pressure, pain, heat, and cold. They are located in our skin and other parts of our body, and they send signals to our brain and spinal cord, which then interprets the signals and allows us to feel these sensations. It is important to note that synapse, cell bodies, and myelin are not directly involved in the detection of these sensations. Synapse is a structure that allows for communication between neurons, or nerve cells, in our brain and spinal cord. Cell bodies are the main part of a neuron that contains the nucleus and other organelles, and myelin is a fatty substance that surrounds and insulates the axons of neurons, allowing for faster transmission of nerve impulses. In summary, receptors are the specialized structures in our body that are stimulated when we feel touch, pressure, pain, heat, and cold. They send signals to our brain and spinal cord, allowing us to feel these sensations. For more information, please see the recommended textbooks.
Which structure in the maize grain stores food?
- A) radicle.
- B) embryo
- C) cytoplasm
- D) endosperm
Correct Answer: D) endosperm
Explanation
In maize grain, there is a structure that stores food. The question is asking which structure performs this function. The options are radicle, embryo, cytoplasm, and endosperm. Radicle is the embryonic root of the plant, while embryo is the young developing plant enclosed in the seed. Cytoplasm is the fluid inside the cell membrane that contains organelles and other components. The correct answer to this question is option D, endosperm. The endosperm is a tissue that is formed inside the seed after fertilization. Its main function is to provide nutrition to the developing embryo. In maize, the endosperm is the largest structure in the seed and is the primary storage tissue for food reserves such as starch and proteins. Understanding the different structures and their functions in the seed is important in the study of plant growth and development. For more information, please see the recommended textbooks.
Which of the organisms listed below is not a micro-organism?
- A) Virus
- B) Tapeworm
- C) Coccus
- D) Vibro cholera
Correct Answer: B) Tapeworm
Explanation
This question is asking us to identify the organism that is not a micro-organism. Micro-organisms are tiny living things that can only be seen with a microscope. The options given are Virus, Tapeworm, Coccus, and Vibro cholera. Out of these options, the correct answer is Tapeworm. Tapeworms are not micro-organisms because they are relatively large parasites that can be seen with the naked eye. They live in the digestive tracts of animals, including humans, and can cause health problems. On the other hand, viruses, cocci, and Vibro cholera are micro-organisms. Viruses are tiny infectious agents that can only replicate inside living cells. Cocci are spherical bacteria that can cause diseases such as strep throat and pneumonia. Vibro cholera is a type of bacterium that causes cholera, a serious and sometimes deadly disease. In summary, Tapeworm is not a micro-organism while Virus, Coccus, and Vibro cholera are micro-organisms. It is essential to understand the characteristics and types of micro-organisms to identify and classify them correctly.
The process by which plants and animals are modified in structure, physiology and behavior in order to survive is known as
- A) evolution
- B) adaptation
- C) succession
- D) hibernation
Correct Answer: B) adaptation
Explanation
Adaptation is the process by which plants and animals change their structure, physiology and behavior in order to survive. This means that they are able to adjust to new environments in order to thrive and avoid extinction. For example, animals that live in cold environments may develop thicker fur or hibernate during the winter to conserve energy and stay warm. Plants may develop deeper roots to access water in arid environments. Evolution, on the other hand, is the process by which species change over many generations due to genetic variation and natural selection. Adaptation is a mechanism of evolution, but evolution encompasses much more than just adaptation. Succession refers to the gradual change in plant and animal communities over time in a particular area, and hibernation is a specific behavior that some animals use to survive harsh weather conditions. Therefore, the correct answer to this question is option B: adaptation.
The farming practice by which an exhausted land is left for a number of years before cultivation is known as
- A) crop rotation
- B) continuous cropping
- C) mono cropping
- D) bush fallowing
Correct Answer: D) bush fallowing
Explanation
The question is asking about a farming practice where a land that has been used for cultivation is left unused for some years before it is used again. This practice is called bush fallowing. It is a way of allowing the land to regain its fertility and improve crop yield. Crop rotation is a farming practice where different crops are planted in a particular order on the same land over a period of time to maintain soil fertility and reduce pest and disease build-up. Continuous cropping is a practice where crops are planted on the same land repeatedly without allowing the soil to rest and regain its nutrients. This practice can lead to soil depletion and may result in low crop yield. Mono cropping, on the other hand, is a farming practice where only one type of crop is grown repeatedly on the same land. This practice can lead to soil depletion, pest and disease build-up and reduced crop yield. In summary, the farming practice where an exhausted land is left unused for some years before cultivation is called bush fallowing. This practice helps to improve soil fertility and crop yield. Crop rotation, continuous cropping and mono cropping are other farming practices used to maintain soil fertility and improve crop yield.
Which of these diseases cannot be controlled by killing the vectors?
- A) River blindness
- B) Malaria
- C) Polio
- D) Cholera
Correct Answer: D) Cholera
Explanation
Some diseases are transmitted through vectors such as mosquitoes and flies. Controlling these vectors can help reduce the spread of the disease. However, not all diseases can be controlled by killing the vectors. The question is asking which of the diseases listed cannot be controlled by killing the vectors. Option A is River blindness, which is transmitted by the blackfly. Killing the blackfly can help control the spread of the disease. Option B is Malaria, which is transmitted by the female Anopheles mosquito. Killing the mosquito can help control the spread of the disease. Option C is Polio, which is not transmitted by a vector but rather through contaminated food and water or contact with an infected person. Controlling vectors would not have any effect on the spread of the disease. Option D is Cholera, which is also not transmitted by a vector but rather through contaminated food and water. Controlling vectors would not have any effect on the spread of the disease. Therefore, the correct answer is Option D. In summary, not all diseases can be controlled by killing the vectors. Diseases such as Polio and Cholera are not transmitted by vectors and therefore controlling vectors would not help control the spread of the disease.
When large numbers of organisms share limited space and resources, the result is
- A) immigration
- B) symbiosis
- C) extinction
- D) competition
Correct Answer: D) competition
Explanation
When there are many organisms that live in the same area and have to compete for limited resources like food, water, and shelter, it is called competition. This means that they are all trying to get the resources they need to survive, and sometimes they may even fight for them. Competition can be between members of the same species or different species. When some organisms are better at competing than others, they may have an advantage and be more likely to survive and reproduce. The other options listed are not correct for this question. Immigration is when organisms come into an area from somewhere else. Symbiosis is when two organisms live together and both benefit from the relationship. Extinction is when all members of a certain species die out. Therefore, the correct answer to this question is option D, competition.
Which of the following parts of the mammalian brain is involved in taking the decision to run rather than walk?
- A) Cerebellum
- B) Medulla oblongata
- C) Cranial nerves
- D) Cerebrum
Correct Answer: D) Cerebrum
Explanation
The question is asking which part of the mammalian brain is responsible for the decision to run instead of walk. The given options are the cerebellum, medulla oblongata, cranial nerves, and cerebrum. To answer this question, we need to understand the functions of these brain parts. The cerebellum is responsible for coordination and balance, while the medulla oblongata controls involuntary functions such as breathing and heart rate. Cranial nerves are responsible for sensory and motor functions of the head and neck. The cerebrum is responsible for conscious thought, perception, and decision-making. Therefore, the correct answer is option D, cerebrum, as it is responsible for making decisions such as whether to run or walk. The cerebrum is the largest part of the brain and has two hemispheres, the left and right, which are responsible for different functions. The left hemisphere is responsible for logical thinking and language, while the right hemisphere is responsible for creativity and spatial awareness. In conclusion, the cerebrum is the part of the mammalian brain responsible for the decision to run rather than walk. It is important to note that the functions of the different parts of the brain are interconnected, and damage to one part can affect the functions of other parts.