JAMB UTME - Biology - 2024

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.

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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. 

DNA carries the genetic information and are generally found in the 

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DNA, which stands for Deoxyribonucleic Acid, is the molecule that contains the genetic instructions for the development, functioning, growth, and reproduction of all known living organisms and many viruses. It is often referred to as the blueprint of life because it holds the instructions needed to build and maintain an organism.

DNA is primarily found in the chromosomes within the cell nucleus. Chromosomes are long, thread-like structures made of protein and a single molecule of DNA. Every human cell, for example, typically contains 23 pairs of chromosomes, amounting to a total of 46. These chromosomes are distributed evenly when cells divide, ensuring that each new cell contains a complete set of genetic information.

Other components like ribosomes, blood, and enzymes do not contain DNA in the way chromosomes do. Ribosomes are cellular structures responsible for protein synthesis, blood is a body fluid important for transporting nutrients and oxygen, and enzymes are proteins that catalyze biochemical reactions. While they all perform essential roles within the organism, they do not serve as carriers of genetic information.

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

The type of variation where there are no remarkable differences between the two extreme individuals is called

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The type of variation where there are no remarkable differences between the two extreme individuals is called continuous variation.

In biology, variation refers to the differences among individuals within a population. When we refer to continuous variation, we're talking about traits that are measured on a scale and show a range of small differences between individuals. An example is human height or weight. In these cases, individuals do not fall into a finite or distinct number of categories, but rather display a smooth and gradual transition across a range.

This type of variation typically results from the combined effects of many genes (polygenic inheritance) and the influence of environmental factors. It presents as a continuous range of expression, forming a bell-shaped curve when graphed, rather than discrete categories. Because of this smooth transition without sharp differences, it's termed as continuous variation.

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The first organisms on Earth are widely believed to have evolved from aquatic habitats. This conclusion is based on several scientific observations and theories.

1. **Early Earth Conditions:** When Earth was still a young planet, conditions were harsh, with a very hot climate and volcanic activity. During this time, the planet's surface was largely covered by oceans which provided a stable environment where simple life forms could potentially thrive. The presence of water is essential because it acts as a medium for chemical reactions and life-supporting processes.

2. **Chemistry of Life:** Water is a solvent that facilitates the necessary chemical reactions required for life. In aquatic environments, organic molecules could dissolve in water, leading to complex chemical reactions, leading to the formation of proteins, lipids, and nucleic acids, which are building blocks of life.

3. **Abiogenesis and the "Primordial Soup" Theory:** One theory of how life began is called the "primordial soup" theory, which suggests that life originated through chemical reactions in the ocean. This soup-like mixture of organic compounds provided the ideal conditions for the first living organisms to form.

4. **Evidence from Fossils:** The oldest known fossils are those of simple microorganisms such as bacteria. These fossils have been found in ancient sedimentary rocks, which were formed in water.

In summary, while there are different types of habitats available on Earth now, the initial conditions billions of years ago favored the formation of life in an aquatic environment. Therefore, it is widely accepted that the earliest life forms evolved in the aquatic habitat.

Which of the following structures enables the exchange of gases in insects?

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Insects have a specialized system for gas exchange, which does not rely on their skin like some other small organisms. Instead, they use a system known as the tracheal system. This system consists of a network of tiny tubes called tracheae.

The tracheae are the main structures that enable the exchange of gases in insects. These tubes extend throughout an insect's body and open to the outside through small openings on the insect's exoskeleton called spiracles.

When an insect breathes, air enters through the spiracles and travels through the tracheae, delivering oxygen directly to the body’s cells. At the same time, carbon dioxide, which is a waste product of respiration, exits the cells via the same tracheal system, leaving the body through the spiracles.

The tracheal system is highly efficient in distributing air directly to the tissues, bypassing the need for a circulatory system to transport gases throughout the body. As such, it provides a direct and effective way for insects to exchange gases necessary for respiration.

The rhizoid of liverwort is

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The rhizoid of liverwort is unicellular and unbranched.

Here's a simple explanation: Liverworts are a type of non-vascular plant that have structures called rhizoids. These rhizoids look like tiny hairs and they help the plant attach to surfaces like rocks or soil. Even though they help with attachment, they do not have the complexity of true roots.

In liverworts, these rhizoids are formed as single cells, which means they are unicellular. Think of them as being like a single long cell that looks like a hair. This single-celled structure is unbranched, meaning it doesn't split or divide into more parts or sections.

In summary, liverwort rhizoids are unicellular and unbranched, helping them secure the plant to various surfaces without forming complex root structures.

Which of the following is a viral disease?

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Out of the diseases listed, Measles is a viral disease. Let me explain this simply:

• Measles: This is a viral disease caused by the measles virus. It is highly contagious and spreads through respiratory droplets when an infected person coughs or sneezes. Measles is characterized by symptoms such as fever, cough, runny nose, inflamed eyes, and a distinctive red rash. Vaccination can prevent measles, making it important for public health.


• Syphilis: This is a bacterial infection caused by the bacterium Treponema pallidum. It spreads through sexual contact. Since it is caused by bacteria, syphilis is a bacterial disease, not a viral one.


• Cholera: A bacterial disease caused by Vibrio cholerae. It spreads through contaminated water and food. Cholera is not a viral disease.


• Typhoid: This is another bacterial disease, which is caused by the bacterium Salmonella typhi. It spreads through contaminated food and water. Typhoid is not viral.

In summary, Measles is the only viral disease among the options provided, as it is specifically caused by a virus, unlike the others, which are caused by bacteria.

Bryophyte is an intermediate group between higher algae and 

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Bryophytes are an intermediate group between higher algae and pteridophytes. Let's break this down to understand why.

Bryophytes include plants like mosses and liverworts. They are often referred to as the simplest form of land plants because they are non-vascular, meaning they do not have specialized tissues, like xylem and phloem, for water and nutrient transport. Instead, they rely on diffusion, which limits their size and requires them to live in moist environments.

On the other hand, pteridophytes are a group of plants that include ferns and are the next step up in complexity from bryophytes. They are important in this context because they mark the transition from non-vascular bryophytes to vascular plants (plants with vascular systems).

Why is this important? This transition is crucial because it represents the evolution of plants from simple, water-dependent organisms to more complex and diverse forms that can live in a wider range of environments, thanks to their vascular systems.

In summary, bryophytes serve as an evolutionary bridge between the simpler algae and the more complex pteridophytes due to their similarities and differences in structure and reproduction.

How many chromosomes will be present in a gamete if the somatic cell has 8 chromosomes?

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In humans and many other organisms, there are two types of cells: **somatic cells** and **gametes**. **Somatic cells** are typical body cells and are **diploid**, meaning they contain two sets of chromosomes—one set from each parent. **Gametes** are reproductive cells (sperm and egg) and are **haploid**, meaning they contain only one set of chromosomes.

In this context, if a **somatic cell** has **8 chromosomes**, it means it is carrying two complete sets of 4 chromosomes each. In order to form a **gamete**, this diploid number must be reduced to a **haploid number** through the process of **meiosis**.

Therefore, the **number of chromosomes** in a **gamete** would be **half** the number of chromosomes in a **somatic cell**. This is because gametes need to have just one set of chromosomes to ensure that when two gametes meet during fertilization, they create a diploid organism.

Thus, if the **somatic cell** has **8 chromosomes**, each **gamete** will have **4 chromosomes**.

Xerophytes are mostly found in the

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Xerophytes are mostly found in arid land. Arid lands are environments that receive very low rainfall, typically classified as deserts or semi-deserts. These areas are characterized by extreme dryness and have conditions that make it difficult for most plants to survive.

Xerophytes are a type of plant specifically adapted to survive in these dry environments. They have special features that help them conserve water. These adaptations include thick, waxy leaves, reduced leaf sizes, deep root systems, and the ability to store water in their tissues. By being able to withstand long periods of drought, xerophytes thrive where other plants cannot.

In contrast, areas like the tropical rainforest and montane forest are characterized by high levels of rainfall and humidity, which support a diverse range of plant and animal life. Similarly, the Sudan savanna has more rainfall than arid lands and supports grasslands and woody plants. Therefore, the environment of arid land is significant to the existence of xerophytes.

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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 organisms that adopt swarming as an adaptation to overcome overcrowding are

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Among the organisms listed, termites are well-known for adopting swarming as an adaptation to overcome overcrowding.

Here's why:

• Termites: In termite colonies, often when the colony becomes too large or overcrowded, a process known as "swarming" occurs. During swarming, winged reproductive termites, also called alates, leave the parent colony in large numbers to find a mate and establish new colonies. This swarming behavior helps reduce the population pressure on the original colony and allows for the spread and survival of the species.
• Tilapia: Fish like tilapia do not swarm as an adaptation to reduce overcrowding. While they might form schools, it is usually for protection, feeding, or migratory purposes rather than to resolve overcrowding.
• Rats: Rats don't adopt swarming behavior; instead, they disperse when populations become high, often seeking new habitats individually or in small groups.
• Agama Lizard: These lizards do not exhibit swarming behaviors. They are typically solitary or may live in loose groups but do not swarm as an adaptation for overcrowding.

Swarming in termites is a crucial natural strategy that allows them to efficiently manage their population and ensure the survival and expansion of their colonies.

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.

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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.

The endocrine gland that is called the master gland is the

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The **pituitary gland** is known as the **"master gland"** of the endocrine system. Let us explore why this is important in a simple way.

The pituitary gland is a tiny, pea-sized organ located at the base of the brain, right behind the bridge of the nose. Despite its small size, it plays a crucial role in regulating vital body functions and general wellbeing.

Why is it called the master gland?

• Control over other glands: The pituitary gland produces and releases hormones that influence and regulate other endocrine glands such as the thyroid gland, adrenal glands, and reproductive glands (ovaries and testes). This is why it is known as the **master gland**.
• Stimulating hormones: It produces several hormones, known as **trophic hormones**, which travel through the bloodstream and tell other glands to produce their hormones. For instance, the pituitary releases thyroid-stimulating hormone (TSH) to regulate the thyroid gland.
• Growth and Development: The pituitary gland releases growth hormone which is critical for normal physical development in children and maintaining muscle and bone mass in adults.
• Well-being and Homeostasis: The hormones it secretes help control blood pressure, energy management, growth, reproduction, and aspects of your emotions.

In summary, the pituitary gland is termed the "master gland" because it has the ability to control many other glands within the endocrine system, playing a pivotal role in maintaining the body's environment or homeostasis.

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The organelle that shows the organism has plant characteristics is

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The organelle that indicates the organism has plant characteristics is the chloroplast. Chloroplasts are essential because they contain chlorophyll, the green pigment crucial for photosynthesis. Photosynthesis is the process by which plants convert light energy from the sun into chemical energy stored in glucose, a type of sugar. This capability to conduct photosynthesis is a key characteristic that differentiates plants from animal cells.

Moreover, plant cells are generally characterized by having an additional cell structure which is the cell wall. The cell wall provides structural support and protection. However, in the context of identifying plant characteristics primarily through organelles, the chloroplast is the distinctive feature.

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**.

Which of the following plants shows hypogeal germination?

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To understand which plants exhibit hypogeal germination, we first need to comprehend what hypogeal germination is. In hypogeal germination, the cotyledons remain below the soil surface after the seed germinates. This occurs because the seedling's epicotyl (the part of the seedling above the cotyledons) elongates, pushing the shoot tip above the ground while the cotyledons stay buried, often serving their purpose as energy reserves.

Let's examine the given options:

• Castor Oil: This plant generally exhibits epigeal germination where the cotyledons come above the ground.
• Groundnut (Peanut): This plant shows hypogeal germination. Here, the cotyledons stay below the soil while the hypocotyl elongates.
• Maize (Corn): Maize undergoes hypogeal germination as its cotyledon remains underground. The seedling grows upward primarily due to elongation of the coleoptile, while the cotyledon stays below the soil.
• Orange: Orange plants are known for exhibiting epigeal germination, where the cotyledons rise above the ground.

From the options provided, both Groundnut and Maize exhibit hypogeal germination. While Groundnut's germination involves the cotyledons staying underground, Maize's germination follows a similar principle with its own adaptations.

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."

The urinary tubules opens into a proximal convoluted tubule coils to form distal by making a

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The urinary tubules are part of the nephron, which is the basic functional unit of the kidney. Each nephron has several segments, including the proximal convoluted tubule, the loop of Henle, the distal convoluted tubule, and the collecting duct.

After the proximal convoluted tubule, the nephron forms a loop known as the loop of Henle. This loop dips down into the medulla of the kidney and is crucial for concentrating urine and maintaining water balance. The form that this loop takes is best described as a U-shaped loop. This shape is because the loop of Henle descends, makes a turn, and then ascends, forming a ‘U’ as it transitions eventually into the distal convoluted tubule.

Therefore, the correct description of the transition from the proximal convoluted tubule to the distal convoluted tubule, via the loop of Henle, is through a U-shaped loop.

The feeding relationship between ruminants and the bacteria in their digestive tract is

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The feeding relationship between ruminants and the bacteria in their digestive tract is symbiotic. In this type of relationship, both the ruminants and the bacteria benefit from each other.

Here's how it works:

• Ruminants are animals such as cows, sheep, and goats. They consume a lot of plant materials, primarily grass, which is rich in cellulose. However, these animals cannot digest cellulose on their own.
• The bacteria living in their digestive tract, particularly in the rumen, help by breaking down cellulose into simpler compounds like fatty acids, which the ruminant can then absorb and use for energy.
• In return, these bacteria benefit by living in a warm and nutrient-rich environment where they can grow and multiply.

This mutual benefit showcases a symbiotic relationship, where both organisms support each other's survival and wellbeing.

The schlerenchyma tissues consist of

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Schlerenchyma tissues are a type of plant tissue known for providing structural support. These tissues are composed of cells that are typically dead at maturity. The cell walls of schlerenchyma tissues are thickened with lignin, which makes them rigid and strong. These characteristics help in supporting the plant body and protecting the plant against external mechanical forces.

To clarify, let's consider the types of cells mentioned:

• Dead Cells: Schlerenchyma tissues consist predominantly of these, as the cells are dead at maturity and filled with lignin.
• Living Cells: These are not characteristic of schlerenchyma tissues. Living cells are more associated with other tissue types, like parenchyma.
• Tracheid Cells: These are specific types of conducting cells in the xylem part of vascular plants, which are different from schlerenchyma.
• Meristematic Cells: These are undifferentiated cells that are capable of division, found in growth regions of plants, unlike the hardened structure of schlerenchyma.

In summary, schlerenchyma tissues consist mainly of dead cells. Their primary role is structural support, making them distinct from tissues composed of living cells, tracheid cells, or meristematic cells.

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.

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 above to answer the question that follows

The zone labelled II is called

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The zone labeled II is likely the littoral zone. The littoral zone is the part of a water body that is close to the shore. It is typically characterized by sufficient sunlight reaching the bottom, allowing aquatic plants to grow. This zone generally supports a wide variety of life because it is nutrient-rich and serves as a crucial area for fish spawning and foraging. Organisms such as aquatic plants, algae, invertebrates, and small fish are often found in the littoral zone. Given that this zone is near the shore, it is far less deep than other zones and can be identified by the presence of this diverse life and vegetation.

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.

In which zone of the marine habitat does the organisms require adaptation for attachment?

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The marine habitat is divided into various zones, each with its own environmental conditions and challenges for the organisms living there. Among these zones, the intertidal zone is the one where organisms require significant adaptation for attachment. The intertidal zone is the area that is exposed to the air at low tide and submerged under water at high tide.

The main reasons organisms need adaptations for attachment in this zone are:

• Wave Action: The intertidal zone experiences strong waves and tidal currents that can easily dislodge organisms from the substrate. To survive, organisms like barnacles and mussels have developed strong attachments, like suction cups or byssal threads, that help them cling to rocks and other surfaces.
• Changing Environmental Conditions: As the tide rises and falls, organisms in the intertidal zone must endure both aquatic and terrestrial conditions. They need to remain attached to a stable surface to avoid being swept away by the tides.
• Preventing Desiccation: During low tide, when they are exposed to air, organisms must prevent drying out. Remaining attached to a secure surface allows them to find crevices or use their protective shells effectively.

Therefore, the intertidal zone specifically requires organisms to have adaptations that ensure they remain securely attached despite the dynamic and challenging conditions encountered daily.

Bile is a greenish alkaline liquid which is stored in the

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Bile is a greenish alkaline liquid that plays a crucial role in the digestion of fats. It is produced by the liver and contains bile acids, which are essential for emulsifying fats, making them easier for enzymes to break down. Once bile is produced by the liver, it is not immediately released into the digestive tract. Instead, it is stored and concentrated in the **gall bladder**. The gall bladder is a small, pouch-like organ located just beneath the liver. It stores bile until it is needed, typically after eating, when it is then released into the small intestine to aid in digestion.

Similar structures that are modified to work in different ways in different organisms are referred to as

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Structures that are similar in form and origin but have been **modified** over time to function differently in various organisms are known as **homologous structures**. These structures indicate a common evolutionary ancestor. For example, the forelimbs of humans, bats, whales, and cats have the same basic bone structure but have adapted differently for tasks such as grabbing, flying, swimming, and walking. Each of these organisms developed modifications in their limb structure to suit their environment and lifestyle, which showcases the concept of homologous structures. Unlike **analogous structures** that have similar functions in different organisms but different evolutionary origins, homologous structures emphasize a common ancestry with different functional outcomes.

Production of healthier offspring, viable seeds and formation of new varieties are good characteristics

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Cross-pollination is a type of pollination that produces healthier offspring, viable seeds, and new varieties.

Cross-pollination involves the transfer of pollen from the anther of one flower to the stigma of a different flower. In contrast, self-pollination is when pollen is transferred within a flower or between flowers on the same plant. Self-pollination is effective in a stable environment, but it can lead to weak offspring that are less adapted to the environment. 

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.

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.

Ecological succession can result from 

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Ecological succession is a natural process by which ecosystems change and develop over time. This process can be initiated by several factors, resulting in the gradual replacement of one community by another until a stable ecosystem, known as a climax community, is achieved.

One such factor that can lead to ecological succession is a newly formed habitat. When an area is newly formed, such as from a volcanic eruption creating new land, or when a glacier retreats exposing bare rock, there is no pre-existing community. Over time, pioneer species such as lichens and mosses begin to colonize the area. As they die and decompose, they contribute organic matter to the soil, making it more hospitable for future plant species. This leads to the gradual development of a more complex community.

A habitat with abundant food might not directly cause ecological succession, but it can support the growth and reproduction of organisms, contributing to the stability and complexity of existing ecosystems. However, changes in food availability can lead to shifts in populations and species interactions, indirectly influencing successional changes.

Another important factor is a habitat with space and light. When a disturbance such as a fire clears an area, removing trees and other vegetation, it creates open space and increases light availability. This situation allows new species to colonize the area, starting a process known as secondary succession. Initially, fast-growing species that require a lot of light dominate the area, but eventually, as the ecosystem matures, it becomes more diverse and balanced.

Lastly, a population of plants on fertile land provides a suitable environment for ecological succession. Fertile soils support a wide variety of plant species, which contribute to the formation of a complex and stable ecosystem over time. As plants grow and die, they enrich the soil, promoting the growth of secondary species until a mature community is established.

In summary, ecological succession can result from newly formed habitats, disturbances that create space and light, and fertile lands. These changes create conditions that allow different species to colonize and thrive, leading to the evolution of ecosystems over time.

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.

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.

The main excretory product of earthworm is

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The main excretory product of an earthworm is urea, with some ammonia gas also being released.

Earthworm is an annelid whose major excretory products are: Urea ~ 50% , Ammonia ~ 20-40% , Creatinine and other nitrogenous compounds ~ 5%

Uric acid is the main excretory product of birds, reptiles, and some insects. 

If the F1 generation allows for self-pollination, what will be the genotypic ratio of the offspring?

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To determine the genotypic ratio of the offspring when the F1 generation allows for self-pollination, first understand the process of Mendelian genetics. In a typical monohybrid cross, let's assume two homozygous parents, one dominant (AA) and one recessive (aa). When these two are crossed, the F1 generation will all have the genotype Aa, which is heterozygous.

If we allow the F1 generation (Aa) to self-pollinate, crossing Aa with Aa, the potential genotypes of the offspring can be determined using a Punnett square:

From this Punnett square, you can see the possible combinations:

• 1 AA
• 2 Aa
• 1 aa

Thus, the genotypic ratio of the offspring is 1 : 2 : 1, which represents one homozygous dominant (AA), two heterozygous (Aa), and one homozygous recessive (aa).

In blood transfusion, a patient with group AB receives

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In blood transfusion, a patient with blood type **AB** is known as a **universal recipient**. This means they can receive red blood cells from any blood group. This is because:

• Blood type **AB** individuals have **both A and B antigens** on the surface of their red blood cells.
• They **do not produce any antibodies** against A or B antigens in their plasma, unlike other blood types.

Therefore, a person with blood type AB can safely receive red blood cells from **donors with A, B, AB, and O blood types**. This is because:

• **Group A donors**: Provide A antigens, which AB individuals accept.
• **Group B donors**: Provide B antigens, which AB individuals accept.
• **Group AB donors**: Provide both A and B antigens, which AB individuals accept.
• **Group O donors**: Provide no A or B antigens, making it compatible with all types.

Therefore, a patient with blood type AB can receive blood from donors with **group O, A, B, or AB**.