JAMB UTME - Biology - 2024

Energy transfer in plants and animals are in the form of

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In both plants and animals, **energy transfer** primarily occurs in the form of **Adenosine Triphosphate (ATP)**. To understand this, let's break it down simply:

1. **What is ATP?** ATP is a molecule that stores and carries energy within cells. Think of it as a small packet or currency of energy that is used to power various cellular processes. The energy is stored in the bonds between the phosphate groups, and when a bond is broken, energy is released to do work in the cell.

2. **How is ATP used in plants?** In plants, ATP is produced during the process of photosynthesis in the chloroplasts. Sunlight energy is captured and used to convert carbon dioxide and water into glucose and oxygen. The light energy is converted into chemical energy in the form of ATP and NADPH. Plants then use ATP to synthesize essential components like glucose, which further fuels various necessary activities of the plant.

3. **How is ATP used in animals?** In animals, ATP is primarily produced during cellular respiration in the mitochondria. Animals consume glucose, and through cellular respiration, they convert it into ATP by using oxygen. This ATP provides the energy needed for various functions such as muscle contraction, nerve impulse propagation, and biosynthetic reactions.

Other molecules like **DNA**, **RNA**, and **GTP** play different roles. DNA stores genetic information, RNA is involved in protein synthesis, and GTP is another energy molecule, but it is primarily used in specific signaling pathways and protein synthesis. ATP remains the main molecule for energy transfer in most cellular activities.

In summary, ATP is the **key energy carrier** in both plants and animals, facilitating essential life processes that require energy.

The formation of cilia and flagella in living cells is carried out with the help of

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The formation of cilia and flagella in living cells is primarily carried out with the help of centrioles.

In eukaryotic cells, cilia and flagella are long, hair-like structures that extend from the surface of the cell and are responsible for movement. They are made up of microtubules, which are protein structures. The base of a cilium or a flagellum is anchored to a cell by a structure called the basal body.

The basal body is very similar in structure to a centriole. Centrioles are cylinder-shaped organelles found in animal cells and are composed of microtubule triplets. When a cell is ready to produce cilia or flagella, the centrioles migrate to the surface of the cell and become basal bodies by aiding in the assembly and organization of these microtubules.

Therefore, the role of centrioles is crucial because they act as the organizing centers for the microtubule structures that comprise cilia and flagella. Without centrioles, a cell would not be able to form these important structures.

In vascular plants, xylem tissue is responsible for

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In vascular plants, the xylem tissue is primarily responsible for the transportation of water. The xylem functions like a network of tubes spreading throughout the plant, from the roots up to the leaves. Its main role is to carry water and dissolved minerals absorbed from the soil by the roots to other parts of the plant. This movement of water is crucial for maintaining plant health as it supports essential processes like photosynthesis and nutrient distribution. Unlike other tissues, xylem is specifically adapted for this task, with its elongated, tube-like structures which provide an effective passage for water movement.

A fruit formed from one flower with many carpels is referred to as

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A fruit formed from one flower with many carpels is referred to as an aggregate fruit.

Let me break that down further for clarity: When a single flower contains multiple ovaries (carpels), each of these ovaries can develop into a small fruit. These small fruits collectively form what is known as an aggregate fruit. This means that although the fruit appears to be one single entity, it is actually made up of many small fruits that are clustered together. Each small fruit in the cluster originates from a single ovary of the flower.

An example of an aggregate fruit is a raspberry or a blackberry, where the clustered small fruits can easily be observed.

Use the diagram above to answer the questions that follow

The part labelled I is

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The part labelled I in the diagram is the oviduct.

To understand why it is the oviduct, let's first understand what an oviduct is. The oviduct, also known as the fallopian tube, is a tube-like structure that connects the ovary to the uterus in female mammals. Its main function is to transport eggs from the ovaries towards the uterus. Fertilization of the egg by sperm typically occurs within the oviduct.

Now, let's look at the structure of the other options:

Placenta: The placenta is an organ that develops in the uterus during pregnancy. It provides oxygen and nutrients to the growing baby and removes waste products from the baby's blood.

Amnion: The amnion is a thin membrane that forms a protective sac filled with amniotic fluid around the developing embryo or fetus.

Uterus: The uterus is a muscular organ where a fertilized egg implants and grows into a fetus during pregnancy.

Based on the description and location given by the diagram, part I is most consistent with the oviduct, as it is likely representing the tube-like structure leading from the ovary to the uterus.

A succession that occurs in an area where there are no pre-existing community is called

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A succession that occurs in an area where there is no pre-existing community is called Primary Succession.

To understand this, imagine a barren landscape where life has never existed before, such as a newly formed volcanic island or a region uncovered by a retreating glacier. In such places, there are no soils or organisms present initially. Here’s how it happens:

• Initial Growth: The first organisms, often called pioneer species, start to colonize the area. They are usually hardy organisms like lichens or certain grasses that can survive in such harsh, lifeless conditions.
• Soil Formation: Over time, these pioneer species help break down rocks into soil as they live and die, adding organic material that enriches the soil.
• Arrival of New Species: As the soil develops, it supports more complex plant species, such as shrubs and trees, which, in turn, create habitats for various animal species.
• Development of a Climax Community: Eventually, the area transforms into a stable and mature ecosystem, known as a climax community, which can sustain a diverse range of life.

In summary, primary succession describes the process of life gradually establishing itself from scratch in an environment that starts with no life or soil, forming an ecosystem over time.

Use the diagram above to answer the question that follows

The part labelled III is

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The diagram provided is not visible since this is a text-based interface. However, I can help explain the parts of an insect as they typically relate to the given options: abdomen, head, maxillae, and thorax. Typically, insects have three main body parts: the head, the thorax, and the abdomen. The maxillae are a part of the mouthparts, usually located on the head. Here is a simple explanation of these parts:

Head: The head is the front part of the insect's body where the eyes, antennae, and mouthparts, such as the maxillae, are located. It is the center for sensory input and feeding.

Thorax: Located just behind the head, the thorax is the middle section of an insect's body. It is where the legs and wings (if present) are attached. It contains muscles that help in movement.

Abdomen: The abdomen is the rear part of an insect's body. It contains vital organs such as those for digestion, excretion, and reproduction. It is generally more flexible than the thorax.

Maxillae: The maxillae are a part of the insect's mouthparts and are found on the head. They assist in manipulating food.

Based on the given options, if Part III is a section of an insect's body segmented into three prominent parts, it usually corresponds to the thorax or abdomen. Without the diagram, a precise answer cannot be given, but based on typical labeling, Part III is often referring to the middle segment; hence, the thorax is a likely match.

A common component of blood and lymph is

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Blood and lymph are both crucial components of the circulatory and immune systems in the body. One of the key components that is common to both blood and lymph is the white blood cell. Here's how:

White blood cells, also known as leukocytes, play a significant role in defending the body against infections, diseases, and foreign invaders. They are an essential part of the immune system.

In blood, white blood cells circulate through the cardiovascular system and help in identifying and attacking pathogens like bacteria, viruses, and other harmful microorganisms.

In lymph, white blood cells are found in the lymphatic fluid and lymph nodes, where they help filter and trap pathogens, preventing them from spreading further into the body.

Therefore, white blood cells are the common component of both blood and lymph, playing a crucial role in the body's defense mechanisms.

The part of the brain that receives sensory impulses of smell is the

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The part of the brain that receives sensory impulses of smell is the olfactory lobe. When you perceive a scent, information from the nose's sensory cells is sent to the olfactory lobe, and it is here that the brain begins the process of identifying the fragrance. The olfactory bulb is the first region that processes smell sensory data, allowing you to discern various odors. Other parts of the brain, like the cerebrum, help process and associate these smells with memories or emotions, but the olfactory lobe is the initial receiver of these sensory signals related to smell.

The cell organelle responsible for the synthesis of protein is the 

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The cell organelle responsible for the synthesis of protein is the ribosome.

To put it simply, ribosomes are like tiny factories within the cell. They read the genetic instructions carried by messenger RNA (mRNA) and use these instructions to assemble amino acids into proteins, which are essential molecules for various cell functions.

Here's how it works in a straightforward manner:

• The cell's DNA contains the "blueprint" for proteins. This information is copied into mRNA in a process called transcription.
• The mRNA travels to the ribosome. The ribosome reads the sequence of the mRNA. This process is called translation.
• As it reads the mRNA sequence, the ribosome assembles amino acids in a specific order, creating a protein chain, which eventually folds into a functional protein.

In summary, the ribosome is an essential organelle for protein synthesis, which is crucial for the cell's structure, function, and regulation of the body's tissues and organs.

A trait that is always expressed during crossing of hereditary characteristics is

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When discussing the crossing of hereditary characteristics, a trait that is always expressed is known as a dominant trait. In genetics, traits are determined by genes, and each trait has two alleles, one from each parent. Alleles can either be dominant or recessive.

Dominant traits are those that are expressed in the organism's phenotype when at least one allele for the trait is dominant. This means that even if the organism has one dominant and one recessive allele for a trait, the dominant trait will take precedence and be observed in the individual.

Conversely, a recessive trait is only manifested in the phenotype if both alleles for that trait are recessive. Therefore, when a dominant allele is present, it will mask the expression of a recessive allele, resulting in the dominance of the trait in question.

For example, if a plant has one allele for tall height (dominant) and one for short height (recessive), the plant will appear tall because the tall allele is dominant.

Use the diagram above to answer the question that follows

The experiment is set up to determine the presence of

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Chlorophyll: Experiments related to chlorophyll typically involve leaves and light exposure to understand photosynthesis. You might see diagrams showing a leaf that is partially covered with foil to demonstrate which parts of the leaf perform photosynthesis.

Starch: To test for the presence of starch, particularly in plants, an experiment usually involves boiling a leaf in water, then in alcohol, and finally treating it with iodine solution. The presence of starch is confirmed by a blue-black color change.

Oxygen: Experiments designed to detect oxygen often involve aquatic plants like Elodea. When the plant is exposed to light, bubbles or gases released would indicate photosynthetic activity, releasing oxygen.

Pigment: Pigment experiments often relate to chromatography, where pigments are separated on a medium like paper. These are used to study various pigments present within plant tissues.

The pigment carrying oxygen in the blood is

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The pigment responsible for carrying oxygen in the blood is haemoglobin. Haemoglobin is a complex protein found in red blood cells. Its primary function is to transport oxygen from the lungs to the rest of the body and return carbon dioxide from the body to the lungs for exhalation. Each haemoglobin molecule can bind to four oxygen molecules, allowing it to carry and efficiently distribute a large amount of oxygen throughout the body.

Here's a simple explanation of how it works:

• Haemoglobin binds with oxygen in the lungs, forming oxyhaemoglobin, which gives blood its bright red color.
• This oxyhaemoglobin travels through the bloodstream to tissues and organs, where it releases the oxygen for cell respiration.
• As it releases oxygen, it picks up carbon dioxide, a waste product from cells, and becomes deoxygenated, giving it a darker color.
• The deoxygenated blood returns to the lungs, where carbon dioxide is released, and the cycle repeats.

It is essential to note that while oxyhaemoglobin is simply haemoglobin that has combined with oxygen, the fundamental oxygen-carrying pigment itself is still haemoglobin.

Hemophilia in humans is controlled by the 

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Hemophilia in humans is controlled by a recessive gene found on the X chromosome. This means that the gene responsible for hemophilia is not dominant and it is located on one of the sex chromosomes, specifically the X chromosome.

Here is how it works:

• Humans have two types of sex chromosomes, X and Y. Females have two X chromosomes (XX), while males have one X and one Y chromosome (XY).
• For hemophilia to occur, the recessive gene must be present on the X chromosome.
• In males: Since males have only one X chromosome, if they inherit the X chromosome with the hemophilia gene, they will have the condition because there is no second X chromosome to offset the effect.
• In females: Because females have two X chromosomes, they need two copies of the recessive gene (one from each parent) to exhibit the disease. If a female has only one copy of the hemophilia gene, she will be a carrier but typically won't show symptoms because the other X chromosome, which does not carry the hemophilia gene, compensates.

In conclusion, hemophilia is inherited as a sex-linked recessive trait. This explains why it is more commonly observed in males than in females.

The total number of ATP produced during glycolysis is

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Glycolysis is the process through which one molecule of glucose is broken down into two molecules of pyruvate, and this process occurs in the cytoplasm of the cell. During glycolysis, two different phases are involved: the energy investment phase and the energy payoff phase. Let's break it down:

Energy Investment Phase: At the start of glycolysis, the cell uses 2 ATP molecules. This phase is necessary to modify the glucose molecule and prepare it for the subsequent reactions.

Energy Payoff Phase: As glycolysis continues, 4 ATP molecules are produced. These ATP molecules are formed when certain intermediates donate phosphate groups to ADP (adenosine diphosphate) to form ATP.

Hence, the net gain of ATP during the glycolytic process is calculated by subtracting the ATP used in the Energy Investment phase from those produced in the Energy Payoff phase.

The calculation is as follows:
ATP Produced = 4 molecules
ATP Used = 2 molecules
Net Gain = 4 - 2 = 2 molecules

Therefore, the total number of ATP produced during glycolysis, when considering the net gain, is 2 molecules of ATP.

Bilateral symmetry,cylindrical bodies and double openings are characteristic features of

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The features you mentioned, namely bilateral symmetry, cylindrical bodies, and double openings, are characteristic of nematodes.

Let's break it down further:

• Bilateral Symmetry: This means that if you draw a line down the middle of the organism, both halves will be mirror images of each other. Nematodes exhibit this kind of symmetry, which is quite common in more complex organisms as it allows for streamlined movement and efficient sensory processing.


• Cylindrical Bodies: Nematodes have long, tube-like bodies that look like a cylinder. This shape helps them move efficiently through their environment, which can be soil, water, or as parasites inside other organisms.


• Double Openings: Unlike some simpler organisms, nematodes have a complete digestive system with a mouth at one end and an anus at the other, allowing for more efficient digestion and nutrient absorption.

In contrast:

• Hydra: These primarily show radial symmetry and have a single opening for both intake and excretion.


• Protozoa and Protists: These are generally single-celled organisms and do not exhibit all three characteristics mentioned (bilateral symmetry, cylindrical bodies, and double openings). They have more varied body plans and structures.

Therefore, based on these descriptions, nematodes clearly align with the features of bilateral symmetry, cylindrical bodies, and double openings.

One of the following is an example of discontinuous variation

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Discontinuous variation refers to variations where the traits are distinct and categorical, meaning individuals can be grouped into distinct categories with no intermediate states. A good example of **discontinuous variation** from the options provided is **blood group**. This is because blood groups are distinct categories (e.g., A, B, AB, O) and individuals belong to one category without any intermediate states.

In contrast, other traits like **shape of the head**, **body complexion**, and **pointed nose** often show a range of variations that are continuous, meaning these traits can have many intermediate forms and cannot be easily categorized into discrete categories. Therefore, **blood group** is an **example of discontinuous variation** because it consists of clearly defined and non-overlapping categories.

A photosynthetic carnivorous plant which feeds on insects is

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The **answer** is insectivorous.

Here's why: In the plant kingdom, there are unique plants known as "carnivorous plants" that have the ability to capture and digest insects and other small animals. Despite obtaining nutrients from these creatures, they still perform photosynthesis, which means they are able to convert sunlight into energy just like any typical plant.

A carnivorous plant that specifically feeds on insects is termed insectivorous. These insectivorous plants have special adaptations such as sticky surfaces, pitcher-like traps, or rapid leaf movements that help them catch insects. Examples include the Venus flytrap and the pitcher plant.

So, while they do engage in capturing insects as a source of additional nutrients, they still depend on sunlight for their energy through the process of photosynthesis.

The chemical and physical composition of soil is an example of

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The chemical and physical composition of soil is an example of an Edaphic factor.

Let's break this down:

Edaphic factors are the characteristics of the soil that influence the organisms living in it. These include the soil's chemical properties, such as its pH, nutrient content, and mineral composition, as well as its physical properties, like texture, structure, and moisture levels. They directly affect plant growth, as plants rely on soil for nutrients and support.

In contrast, the other factors mentioned are not directly related to soil composition:

• Climatic factors relate to weather conditions such as temperature, humidity, and rainfall.
• Topographic factors concern the landscape features like elevation and slope.
• While chemical factors might sound similar, they are more general and pertain to chemical aspects in various environments, not just soil.

Thus, when we talk about the chemical and physical composition of soil, we are specifically referring to its edaphic factors.

Which of the following processes takes place in the carbon cycle? 

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The carbon cycle is a natural process through which carbon is exchanged between different components of the Earth, including the atmosphere, oceans, soil, and living organisms. The process in the carbon cycle related to your question is combustion.

Combustion is the process of burning organic material such as fossil fuels (coal, oil, and natural gas) or biomass (like wood). When these materials are burned, they react with oxygen to produce energy, releasing carbon dioxide (CO₂) and water vapor as by-products. This carbon dioxide is then released into the atmosphere, where it can be absorbed by plants through photosynthesis, thereby continuing the carbon cycle.

To clarify why the other processes are not part of the carbon cycle:

• Evaporation is the process where water from lakes, rivers, and oceans changes from a liquid to a gas or vapor. This is part of the water cycle, not the carbon cycle.


• Nitrification is a process in the nitrogen cycle, where ammonia is converted into nitrites and then nitrates, involving the transformation of nitrogen compounds. It does not involve carbon directly.


• Transpiration is the process through which water is absorbed by plant roots and then released as water vapor from plant leaves. This is also part of the water cycle.

In summary, combustion is the process in the list above that plays a direct role in the carbon cycle by releasing carbon dioxide into the atmosphere.

The common examples of trees found in the desert are

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Deserts are characterized by their arid conditions, meaning they receive very little rainfall throughout the year. To survive in such environments, plants need special adaptations. Among the plant varieties, the trees commonly found in deserts include **cacti** and the **baobab tree**. Here's a brief explanation of why these trees are well-suited to desert environments:

• Cacti: Cacti are well-known for their ability to store water. They have thick, fleshy stems that retain water, allowing them to survive long periods of drought. Additionally, cacti have spines instead of leaves. Not only do these spines offer protection, but they also reduce water loss by minimizing the surface area exposed to the harsh desert sun.
• Baobab Trees: Baobabs are distinct because of their massive trunks, which can store large quantities of water—essential for enduring extended dry periods in desert locales. Their ability to thrive in arid regions stems from this water storage feature, making them symbols of resilience in the desert habitat.

Plants like **raffia palm**, **coconut**, **white and red mangrove**, and **shea-butter** trees are not typically found in desert environments because they require more moisture and different soil conditions compared to the harsh, dry lands of the desert.

Use the diagram to answer the question that follows

The flower of plants belongs to part labelled

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The flower is the reproductive organ of a plant. It is a plant organ, which is defined as a group of tissues that work together to perform a specific function. 

The changes of living organisms over generation is referred to as

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The process by which living organisms change over generations is referred to as organic evolution. This concept explains how species undergo gradual change over long periods of time, which can ultimately result in the emergence of new species. These changes are brought about by mechanisms such as mutation, natural selection, gene flow, and genetic drift. As a result, populations of organisms adapt to their environments and can become better suited to survive and reproduce. The concept of organic evolution is a fundamental principle in biology, as it helps us understand the history of life on Earth and the shared ancestry of all living organisms.

Darwin's theory of evolution is based on the principle of 

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Darwin's theory of evolution is based on the principle of natural selection. This concept explains how species change over time in response to their environment.

Here's a simple way to understand it: In any given environment, there are more individuals born than can survive. These individuals vary slightly in their traits, such as color, size, speed, etc. Some of these variations might give an individual a slight edge in the environment, helping them to survive better or reproduce more than others. For example, a faster rabbit might escape predators more successfully than slower ones.

These advantageous traits are more likely to be passed down to the next generation. Over many generations, these beneficial traits become more common in the population. This process is known as natural selection because it "selects" the traits that best suit the environment. Consequently, the species slowly evolves and adapts to their surroundings.

The key point is that natural selection is a gradual process driven by the survival and reproduction of individuals with favorable traits in a specific environment. Unlike the other options, it doesn't rely on the use or disuse of organs, the inheritance of acquired characteristics during an individual's life, or sudden genetic changes known as mutations.

Which of the Nigeria states is Northern guinea savanna located?

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The **Northern Guinea Savanna** is an ecological zone in Nigeria characterized by a mixture of grasslands and scattered trees. This vegetation belt lies between the Sudan Savanna in the north and the Southern Guinea Savanna in the south. The vegetation in this region is adapted to longer wet seasons compared to the Sudan Savanna and shorter ones compared to the Southern Guinea Savanna.

Among the states listed, **Kwara State** is where the **Northern Guinea Savanna** is located. Kwara is positioned in the north-central part of Nigeria, which aligns with the geographical location of the Northern Guinea Savanna. It features the characteristic landscape of mixed grasslands and trees, supporting both agriculture and livestock rearing.

In contrast, **Borno and Kano** are located further north, closer to or within the Sudan Savanna zone, which is more arid. **Oyo state**, on the other hand, is located in the southwestern part of Nigeria and is part of the forested regions or the Southern Guinea Savanna, which receives more rainfall and supports more dense vegetation compared to the Northern Guinea Savanna.

Thus, the correct answer is **Kwara State** as it lies within the **Northern Guinea Savanna** ecological zone.

The resemblance of an organism to another organism as means of enhancing it's chances of survival in its habitat is known as

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The phenomenon you are referring to is called mimicry. Mimicry occurs when one organism, known as the mimic, evolves to resemble another organism, called the model, in order to gain some advantage. This resemblance can help the mimic improve its chances of survival within its habitat.

Mimicry typically involves visual similarities, although it can also extend to auditory, olfactory, or behavioral traits. By mimicking another organism, the mimic may benefit in various ways, such as avoiding predators, enhancing foraging success, or improving reproductive opportunities.

For example, some harmless species may mimic the appearance of dangerous or unpalatable species to deter predators, while others might conceal themselves by resembling the environment or other benign organisms. This strategy not only helps them evade threats but sometimes aids in approaching prey. Overall, mimicry is a powerful evolutionary adaptation that plays a crucial role in the survival of many species.

Reproduction in paramecium is by

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Paramecium is a single-celled organism that belongs to the group of protists known as ciliates. The primary method of reproduction in paramecium is through binary fission. Let's break down what that means:

Binary Fission: This is a type of asexual reproduction, which means it does not involve the fusion of gametes (sperm and egg). Instead, it is a simple division process in which the organism creates a copy of itself. Here is how it works in paramecium:

• The paramecium first duplicates its genetic material, which is contained within its nucleus. During this process, the genetic information is doubled to ensure that each new cell has the same DNA as the parent cell.
• Once the DNA is replicated, the paramecium's cell elongates, making it ready to split.
• Next, the cell divides into two almost equal halves. Each new cell, or daughter cell, receives a copy of the original genetic material.
• Finally, these daughter cells grow to the size of the original parent cell and the process can begin again.

This process of binary fission allows paramecia to reproduce quickly and efficiently, leading to exponential population growth under favorable conditions. Unlike other methods like budding, spore formation, or fragmentation, binary fission is a straightforward division of the cell into two identical parts.

Conclusion: Paramecium reproduces mainly by binary fission, a type of asexual reproduction that results in two genetically identical offspring from a single parent organism.

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Iron is a crucial nutrient for plants due to its involvement in several important biological processes. Let's break these down:

• Aids in the formation of chlorophyll and proteins: Without iron, plants cannot produce chlorophyll, the pigment that gives plants their green color and is essential for photosynthesis, the process through which plants convert sunlight into chemical energy. Additionally, iron is a component of some proteins and enzymes that facilitate various metabolic reactions within the plant.
• Helps in cell division: Iron plays a role in cell division and plant growth by being a part of enzymes that drive the synthesis of DNA. This is vital for the overall development and reproduction of plant cells.


• Protects the plants from pest attack: While iron is not primarily known for its role in pest protection, healthy plants, which benefit from sufficient iron, are generally more resilient to diseases and pests.
• Fastens fruits maturation: A well-functioning plant metabolism, aided by adequate iron levels, ensures that the plant's life cycle progresses timely, allowing fruits to mature at the right time.

In summary, iron is crucial because it is involved in the formation of chlorophyll, proteins, and DNA, all of which are essential for the growth, energy production, and reproduction of the plant. This, in turn, helps the plant grow healthy and resilient.

Infectious diseases are caused by

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Infectious diseases are illnesses caused by certain harmful microorganisms that invade the body. These microorganisms can be grouped into several categories. Among these categories, two of the most notable are bacteria and protozoa. Both of these groups contain species that can lead to disease.

Bacteria are single-celled microorganisms. While many bacteria are harmless or even beneficial to humans, some can cause diseases such as strep throat, tuberculosis, and urinary tract infections. Bacteria are living organisms that reproduce by themselves, and they can sometimes produce toxins that harm the host.

Protozoa are a diverse group of single-celled organisms that live in a variety of moist or aquatic environments. Many protozoa are harmless, but some can cause serious diseases. For example, the protozoan parasite Plasmodium causes malaria, a serious disease transmitted by mosquitoes.

Protists is a broader term that includes protozoa as well as algae and fungi-like organisms, and while not all protists cause disease, the term could refer to certain disease-causing protozoans.

Amoebas are a type of protozoan characterized by their changing shape and movement. Although many amoebas are harmless, some types, such as Entamoeba histolytica, cause illnesses like amoebic dysentery, which is characterized by diarrhea and stomach pain.

In summary, infectious diseases can be caused by bacteria and a variety of protozoa, including specific types like amoebas. Understanding these different microorganisms helps in diagnosing and treating the diseases they cause.

The web-feet of frogs and toads is basically for 

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The **web-feet** of frogs and toads are primarily for **swimming**. Frogs and toads have webbed feet, which means their toes are connected by a thin membrane. This structure acts like a paddle, allowing them to push against water more effectively and move with greater ease and speed when they swim.

**Webbed feet** increase the surface area of their feet, providing more propulsion through the water, much like the way a duck's or other aquatic animal's webbed feet work. While they may also use their feet for other activities like **leaping** and **walking**, the primary adaptation and evolutionary advantage of having webbed feet is to enhance their ability to **swim** efficiently. Swimming is essential for frogs and toads because many of them live near water bodies and often have to escape predators, hunt for food, or move between land and water habitats.

Use the diagram above to answer the question that follows

The organism belongs to kingdom

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The diagram is that of the virus. Viruses are obligate parasites, meaning they can't produce their own energy or proteins. They enter the host cell and use the cell's machinery to make their own nucleic acids and proteins. Viruses also use the host cell's lipids and sugar chains to create their membranes and glycoproteins. This parasitic replication can severely damage the host cell, which can lead to disease or cell death. They usually enter your body through your mucous membranes. These include your eyes, nose, mouth, penis, vagina and anus.

Viruses are a unique type of organism that are not plants, animals, or bacteria. They are often classified in their own kingdom. However, for the sake of the question, since most of their attributes and metabolic activities are more of the bacteria, we'll go with option A - Monera

A community with a population of two million three hundred and ten thousand people living in an area of two thousand three hundred and ten square kilometres has a population density of

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To calculate the population density of a region, you need to divide the **total population** by the **area** they are living in. This will give you the number of people per unit area, typically per square kilometer in this case.

Given:

• Total population: 2,310,000 people
• Area: 2,310 square kilometers

The formula for population density is:

Population Density = Total Population / Area

By plugging in the given values:

Population Density = 2,310,000 / 2,310 = 1,000

This means there are **1,000 people per square kilometer** in this community. Therefore, the correct population density is **1,000**.

After fertilization in plants, the zygote develops into

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After fertilization in plants, the zygote develops into an embryo. This process is a critical stage in the life cycle of a plant. Let me explain it in simple steps:

• When a pollen grain fertilizes an ovule, the male gamete (sperm) unites with the female gamete (egg cell) within the ovule, leading to the formation of a zygote.
• The zygote is the first cell of the new plant, and it will initially undergo a series of mitotic cell divisions. As it divides and grows, it transforms into a small, multicellular structure known as the embryo.
• The embryo is essentially the young plant encased within the protective environment of the seed, and it will later develop into the mature plant.

Therefore, after fertilization, the focus on growth centers around the development of the embryo, which is a crucial step in the successful reproduction and life cycle continuation of plants.

The transmission of diseases through contamination of food is an economic importance of

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The transmission of diseases through contamination of food is an economic importance primarily related to cockroaches.

Cockroaches are considered pests that thrive in unsanitary environments. They are known to carry various pathogens, such as bacteria, viruses, and parasites, on their bodies and in their droppings. When they come into contact with food, they can contaminate it, leading to foodborne diseases.

This contamination can have several economic impacts:

• Health Care Costs: People who consume contaminated food may fall ill, leading to medical expenses for treatment and care.
• Workplace Productivity: Sick employees may need to take time off work, affecting productivity and economic output.
• Restaurant and Business Reputation: Establishments found to have unsanitary conditions due to cockroach infestations can face loss of customers, declining sales, and potential closure.
• Regulatory Fines: Businesses may incur fines or penalties from health and safety agencies if they fail to control cockroach infestations.

Therefore, managing and preventing cockroach infestations is crucial to safeguarding public health and protecting economic interests associated with food safety.

The oxygen transported to all parts of the body during blood circulation is used for the

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The oxygen that is transported to all parts of the body during blood circulation is primarily used for the release of energy from food. This process is also known as cellular respiration.

Here's how it works:

• Inside the cells, oxygen plays a crucial role in breaking down nutrients like glucose through a process called aerobic respiration.
• During aerobic respiration, glucose reacts with oxygen to produce carbon dioxide, water, and most importantly, energy in the form of adenosine triphosphate (ATP).
• ATP is the energy currency of the cell and is used to power various biological processes, enabling the cells and the body to function properly.

Thus, the presence of oxygen is vital for cells to convert the energy stored in food into a form that can be used for all activities, from metabolic processes to muscle contraction. In summary, the primary purpose of oxygen transportation during blood circulation is for the release of energy from food, which is essential for maintaining life and performing all physiological functions.

The cone in the retina of eye is an example of

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The cone in the retina of the eye is an example of a cell. Let me explain this further in a simple and comprehensive way:

Our eyes have a part called the retina, which is like a screen at the back of the eye. It captures the images we see and sends them to the brain for processing. The retina contains special cells that help us detect light and color. These are primarily two types: rods and cones.

The cones are specialized cells in the retina responsible for allowing us to see in color. They function under bright light conditions and help us perceive different colors and details. There are three types of cones, each sensitive to: red, green, or blue light. Together, they allow us to see a full spectrum of colors.

Therefore, in the hierarchy of biological organization, a cone is considered a cell, as it is the smallest functional unit that contributes to vision.

Use the diagram above to answer the question that follows.

Examples of non-vascular plants are labelled 

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Marchantia is a member of the Marchantiaceae, the Marchantia family. This family is one of many thalloid liverwort families or bryophyta. A thalloid liverwort is strap-like and often forms large colonies on the surface on which it grows. A liverwort is non-vascular green plant. 

Spirogyra is a green algae that is a member of the Thallophyta division. It is also known as water silk, mermaid's tresses, and blanket weed. 

Dryopteris, also known as wood ferns, male ferns, or buckler ferns, is a genus of ferns in the Dryopteridaceae family, of pteridophyta.

Cycads are part of the order Cycadales and the division Cycadophyta, which are both groups of gymnosperms.

Maize belongs to the group angiosperms. Angiosperms are plants that have a well-developed vascular system 

Only bryophytes(Marchantia) -  I and Thallophytes (Spirogyra) - II are non- vascular, others have vascular systems. Therefore option A is the correct answer.

The cells responsible for transmitting messages to the effectors are

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The cells responsible for transmitting messages to the effectors are motor neurons. These neurons play a critical role in the nervous system by transmitting impulses from the central nervous system (such as the brain and spinal cord) towards the muscles and glands, which are collectively known as effectors.

Here's a simple breakdown of how this process works:

• Signal Initiation: The process begins with the central nervous system sending an electric signal.
• Transmission: The motor neurons receive the signals and carry them along their axons, which are long nerve fibers.
• Activation of Effectors: When the signal reaches the end of the motor neuron, it causes the release of neurotransmitters, which then stimulate the effectors. In response, muscles may contract, or glands may begin secretion.

Effectors are essential as they perform actions in response to neural signals, making motor neurons integral in generating coordinated movement and various physiological responses. In contrast, sensory neurons carry information from sensory receptors to the central nervous system, relay neurons (interneurons) facilitate communication within the central nervous system, and hair cells are specialized sensory receptors in the auditory and vestibular systems. Thus, the primary role of motor neurons is to convey signals to effectors to initiate a response or action.

Which of the following evidences of evolution employs the use of radio-isotope dating?

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The evidence of evolution that employs the use of radio-isotope dating is fossil records.

Let me explain this further. Fossils are the preserved remains or traces of organisms that lived in the past. Scientists use fossils to understand the history of life on Earth and how species have changed over time. But to make meaningful conclusions, they need to know the age of these fossils.

This is where radio-isotope dating comes into play. Radio-isotope dating, also known as radiometric dating, is a technique used to determine the age of rocks and fossils. It measures the decay of radioactive isotopes in materials.

Here's a simple way to understand it: you can think of radioactive isotopes as tiny clocks contained within rocks and fossils. These isotopes decay at a constant rate over time. By measuring the amount of remaining isotopes and knowing their half-life (the time it takes for half of the isotopes to decay), scientists can calculate how long the isotopes have been decaying. This gives them the age of the fossil or rock, helping to place it in the context of Earth's history.

In conclusion, fossil records are the evidence of evolution that utilize radio-isotope dating to provide a time frame and chronological context for evolutionary events.

The major building block of an organism is...

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The major building block of an organism is Carbon. Let me explain why:

1. Backbone of Organic Compounds: Carbon is the fundamental component in organic compounds, which form the basis of all living organisms. This includes carbohydrates, proteins, lipids, and nucleic acids (DNA and RNA). These molecules are crucial for the structure and function of cells.

2. Versatile Bonding: Carbon atoms can form four covalent bonds with other atoms. This allows carbon to form a diverse array of molecules, ranging from simple methane (CH₄) to complex macromolecules like proteins and nucleic acids.

3. Stability: Carbon-based molecules are stable and can exist in various forms. This stability is critical for building compounds that are integral to life.

4. Flexibility in Forming Structures: Carbon chains can form rings, long chains, and branched formations, providing structural diversity that supports the complex needs of living organisms.

While elements like nitrogen, oxygen, and hydrogen are also essential, carbon's unique ability to bond in multiple and versatile ways is why it is considered the backbone of life. Hence, we often refer to life as "carbon-based."