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Question 1 Rapport
Détails de la réponse
The major buffer in blood is the **bicarbonate buffer system**. The bicarbonate buffer system maintains the pH of the blood and is integral for physiological homeostasis. This system primarily involves **bicarbonate ions (HCO3-)** and works in conjunction with carbonic acid (H2CO3).
In the blood, the bicarbonate buffer system works by a reversible chemical reaction:
CO2 + H2O ⇋ H2CO3 ⇋ HCO3- + H+
Here’s how it functions:
This system is exceptionally effective at buffering rapid changes in pH. The respiratory and renal systems support the bicarbonate buffer system. The lungs regulate the concentration of CO2, and the kidneys control the concentration of HCO3-.
While erythrocytes (red blood cells), leucocytes (white blood cells), and lymph are components of blood, they do not play a primary role in the buffering systems of blood. The bicarbonate buffer system is primarily a chemical buffer that functions independently of these cellular components.
Question 2 Rapport
Détails de la réponse
In a genetic cross, when we have a heterozygous red flower plant (Rr) and a white flowered plant (rr), we can use a Punnett square to determine the probability of each possible genotype of the offspring.
The parent genotypes are:
We can set up a Punnett square with the following alleles:
| r | r | |
|---|---|---|
| R | Rr | Rr |
| r | rr | rr |
From the table, we can see the following possible outcomes for the offspring:
Therefore, the probability that the offspring will be Rr is 2 out of 4 (or 1/2).
Question 3 Rapport
The chemical and physical composition of soil is an example of
Détails de la réponse
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:
Thus, when we talk about the chemical and physical composition of soil, we are specifically referring to its edaphic factors.
Question 4 Rapport
Production of healthier offspring, viable seeds and formation of new varieties are good characteristics
Détails de la réponse
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.
Question 5 Rapport
Lamarck's theory of evolution is based on the idea of
Détails de la réponse
Lamarck's theory of evolution is based on the idea of the inheritance of acquired traits. According to Lamarck, organisms can change during their lifetime by using or not using certain parts of their body. For example, he suggested that if a giraffe stretches its neck to reach higher leaves on trees, its neck will become longer. Furthermore, these traits that were acquired during an organism's lifetime could then be passed down to its offspring. Thus, the next generation would inherit the longer neck, leading to a gradual evolution of longer-necked giraffes over generations. This theory was one of the earliest ideas about evolution, although it has since been largely superseded by Darwin's theory of natural selection.
Question 6 Rapport
After fertilization in plants, the zygote develops into
Détails de la réponse
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:
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.
Question 7 Rapport
Infectious diseases are caused by
Détails de la réponse
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.
Question 8 Rapport
The resemblance of an organism to another organism as means of enhancing it's chances of survival in its habitat is known as
Détails de la réponse
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.
Question 9 Rapport
A medium texture soil with high organic matter is
Détails de la réponse
A medium texture soil with high organic matter is best described as loamy soil. Here is why:
Loamy soil is a mix of three main soil types: sand, silt, and clay. This combination creates a soil that is rich in organic matter and nutrients, providing an excellent environment for plant growth.
Key Characteristics of Loamy Soil:
Understanding the benefits and characteristics of loamy soil can help in recognizing its importance in agriculture and gardening. Unlike clay or sandy soils, which might have issues with drainage or nutrient retention respectively, loamy soil offers a balance that is conducive for a wide variety of plants.
Question 10 Rapport
The process by which plants loss water to the atmosphere is
Détails de la réponse
The process by which plants lose water to the atmosphere is referred to as transpiration. Let's break this down:
Transpiration is the process where water absorbed by plant roots is eventually released into the atmosphere as water vapor through the plant's leaves. This primarily occurs through small openings on the leaves known as stomata.
Here's how it happens:
Transpiration is crucial for plants because it not only helps them get rid of excess water but also plays a significant role in cooling the plant and enabling the upward movement of essential nutrients from the soil. It also contributes to the water cycle by adding moisture to the atmosphere.
In summary, transpiration is an essential process where plants lose water to the atmosphere, playing an important role in plant health and environmental equilibrium.
Question 11 Rapport
Which of the following statements explains the theory of natural selection?
Détails de la réponse
The theory of natural selection, proposed by Charles Darwin, explains how species evolve over time through the survival and reproduction of individuals that are better adapted to their environment. Let's break down the concepts related to the statements you've provided:
1. There is no struggle for existence: This statement is incorrect in the context of natural selection. The theory is based on the concept of a "struggle for existence," which means that due to limited resources, such as food, water, and shelter, individuals within a species must compete to survive. Because only the organisms that are better adapted to their environment can survive and reproduce, this statement does not correctly explain the theory.
2. New species get better adaptation: While partially related, this statement isn’t a direct explanation of natural selection. Natural selection leads to the evolution of better-adapted individuals within a species, rather than creating entirely new species immediately. Over long periods, accumulated adaptations may lead to the emergence of new species, a process known as speciation.
3. The weaker offspring are eliminated: This statement is a key aspect of natural selection. The process favors individuals with traits that improve their chances of survival and reproduction in a given environment. Over time, weaker individuals or those with less advantageous traits are unlikely to survive and reproduce, leading to a gradual increase in the prevalence of advantageous traits within the population.
4. Unused structures disappear later: This refers more to the concept of "use and disuse," which is associated with Lamarckism, rather than Darwin's theory of natural selection. In natural selection, it's not the unused parts that disappear; rather, changes in the environment can lead to certain traits becoming more or less advantageous, affecting their prevalence in future generations.
In summary, the statement that "the weaker offspring are eliminated" best encapsulates a core component of the theory of natural selection, which is the differential survival and reproduction of individuals based on their inherited traits.
Question 12 Rapport
How many chromosomes will be present in a gamete if the somatic cell has 8 chromosomes?
Détails de la réponse
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**.
Question 13 Rapport
Similar structures that are modified to work in different ways in different organisms are referred to as
Détails de la réponse
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.
Question 14 Rapport
Use the diagram above to answer the question that follows:
Recombination of genes at fertilization is represented by the part labelled
Détails de la réponse
During prophase I, homologous chromosomes from each parent pair up and exchange genetic material, a process known as crossing over. This process creates new combinations of genes in the resulting gametes. When two gametes unite during fertilization, the offspring will have a unique combination of DNA.
Genetic recombination during fertilization takes place in the prophase I stage of meiosis ( part labelled III)
Question 15 Rapport
The part of the kidney where the selective reabsorption takes place is
Détails de la réponse
The part of the kidney where selective reabsorption takes place is the Henle's loop, also known as the Loop of Henle.
Here's a simple explanation:
The kidneys are responsible for filtering blood, removing waste, and balancing bodily fluids. This is accomplished through structures called nephrons, each of which functions like a tiny processing plant. A nephron comprises various parts, including the glomerulus, Bowman's capsule, and the Loop of Henle.
Initially, blood is filtered in the glomerulus, and the resulting fluid then enters the Bowman's capsule. However, this fluid contains essential nutrients and ions that our body needs. Therefore, it must be reabsorbed back into the bloodstream.
The Loop of Henle plays a critical role in this reabsorption process. It creates a concentration gradient that allows water, sodium, chloride ions, and other substances to be reabsorbed selectively into the blood. This ensures that vital nutrients and electrolytes are not lost in the urine.
The Henle's loop is integral in forming concentrated urine, enabling the body to conserve water and important nutrients while still eliminating waste effectively. Thus, it is the site where selective reabsorption primarily occurs.
Question 16 Rapport
Use the diagram above to answer the question that follows
The zone labelled II is called
Détails de la réponse
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.
Question 17 Rapport
The cone in the retina of eye is an example of
Détails de la réponse
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.
Question 18 Rapport
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
Détails de la réponse
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:
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**.
Question 19 Rapport
The common examples of trees found in the desert are
Détails de la réponse
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:
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.
Question 20 Rapport
In which zone of the marine habitat does the organisms require adaptation for attachment?
Détails de la réponse
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:
Therefore, the intertidal zone specifically requires organisms to have adaptations that ensure they remain securely attached despite the dynamic and challenging conditions encountered daily.
Question 21 Rapport
The main excretory product of earthworm is
Détails de la réponse
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.
Question 22 Rapport
In glycolysis, glucose is broken down through series of reactions in the presence of enzyme and absence of oxygen to produce
Détails de la réponse
Glycolysis is a biochemical process through which glucose, a six-carbon sugar, is broken down into two molecules of a three-carbon compound called **pyruvic acid** or **pyruvate**. This process occurs in the **absence of oxygen** and is also referred to as anaerobic respiration. During glycolysis, energy stored in glucose is released, and a net gain of **two molecules of ATP (adenosine triphosphate)** is produced, which serves as a direct energy source for cellular activities.
Here is a brief explanation of the main steps involved in glycolysis:
In summary, during glycolysis in the absence of oxygen, glucose is transformed into **pyruvic acid and a net gain of ATP molecules**, making the answer **pyruvic acid + ATP**.
Question 23 Rapport
Use the diagram above to answer the question that follows
The organelle that shows the organism has plant characteristics is
Détails de la réponse
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.
Question 24 Rapport
Which of the following plant is found in the ground layer of a tropical rainforest in Nigeria?
Détails de la réponse
In a tropical rainforest, the forest layers are characterized by distinct types of vegetation. The **ground layer** hosts plants and organisms that typically thrive in low-light conditions due to the dense canopy above. Such layers often consist of mosses, ferns, and small plants that can grow with limited sunlight.
When considering the plants listed:
Thus, the answer is **liverwort**, as it appropriately matches the ecological niche of the **ground layer** in a tropical rainforest.
Question 25 Rapport
Détails de la réponse
The main excretory products of plants during metabolism are carbon dioxide, excess water, and nitrogenous compounds.
Plants produce carbon dioxide as a metabolic waste product during respiration, while oxygen is a metabolic waste product from photosynthesis. Excretion of gaseous waste in plants takes place through stomatal pores on leaves. Oxygen released during photosynthesis is used for respiration while carbon dioxide released during respiration is used for photosynthesis.
Question 26 Rapport
If the F1 generation allows for self-pollination, what will be the genotypic ratio of the offspring?
Détails de la réponse
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:
| A | a | |
| A | AA | Aa |
| a | Aa | aa |
From this Punnett square, you can see the possible combinations:
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).
Question 27 Rapport
One of the characteristics of secondary succession is that it
Détails de la réponse
Secondary succession is a process that occurs when an ecosystem that has already been colonized by living organisms is disturbed, but the soil and some of its organisms remain intact. This can happen after events such as forest fires, hurricanes, or human activities like farming. In contrast to primary succession, secondary succession does not start from scratch or a barren surface.
The characteristic of secondary succession is that it starts on an already colonized surface. This means that the area had life before but was disturbed, so the succession process is somewhat quicker since the soil contains seeds, nutrients, and microorganisms that speed up the recovery of the ecosystem. This contrasts with primary succession, which starts on bare and barren surfaces, like rocks or volcanic lava fields, where soil needs to form first.
Question 28 Rapport
The urinary tubules opens into a proximal convoluted tubule coils to form distal by making a
Détails de la réponse
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.
Question 29 Rapport
A common component of blood and lymph is
Détails de la réponse
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.
Question 30 Rapport
A photosynthetic carnivorous plant which feeds on insects is
Détails de la réponse
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.
Question 31 Rapport
A form of adaptive colouration that helps animals to remain unnoticed is
Détails de la réponse
A form of adaptive coloration that helps animals to remain unnoticed is called countershading.
Countershading is a type of camouflage where an animal's coloration is darker on the upper side and lighter on the underside. This coloration helps them to blend into their surroundings better, reducing the chance of being seen by predators or prey.
Here's a simple explanation of how it works:
This dual shading effect reduces the animal's shadow and profile, making them less visible and thereby improving their chances of survival. Other terms like hibernation, aestivation, and migration refer to processes that are not directly related to coloration or camouflage. Therefore, countershading is the correct term for adaptive coloration that aids in concealment.
Question 32 Rapport
Loamy soil is characterized by
Détails de la réponse
Loamy soil is characterized by a distinct combination of features that make it particularly favorable for plant growth. It contains a balanced mixture of three types of soil particles: sand, silt, and clay. This combination gives loamy soil its unique properties.
High Humus: Loamy soil is known for having a high content of organic matter, often referred to as humus. Humus is important because it improves soil fertility, provides vital nutrients for plants, and helps retain moisture.
Moderate Porosity: Loamy soil has a structure that provides moderate porosity. This means it can hold water effectively while also allowing excess water to drain away, ensuring that plants have both the water and air they need. It balances water retention and aeration very well.
Because of these characteristics, loamy soil is considered one of the best soils for agriculture and gardening. Therefore, the description that best characterizes loamy soil is high humus and moderate porosity.
Question 33 Rapport
The web-feet of frogs and toads is basically for
Détails de la réponse
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.
Question 34 Rapport
Which of the following structures enables the exchange of gases in insects?
Détails de la réponse
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.
Question 35 Rapport
A discontinuous morphological variation often used in crime detection is the
Détails de la réponse
In crime detection, the most popular discontinuous morphological variation used is finger prints.
Here's a simple way to understand why:
Defining Morphological Variation: Morphological variation refers to differences in the form and features of living organisms. A variation is termed as 'discontinuous' when it falls into distinct categories with no intermediates. For example, you either have a particular feature or you don't.
Why Fingerprints are Discontinuous: Fingerprints are a good example of discontinuous variation because each individual's set of fingerprints is unique. There are no gradual transitions – you either have a specific fingerprint pattern, like a loop, whorl, or arch, or you don't.
Application in Crime Detection: Because everyone has a unique set of fingerprints and these can be easily left on surfaces, fingerprints are a powerful tool in crime detection. Investigators gather fingerprint evidence from crime scenes and compare them with fingerprint databases to identify suspects.
In conclusion, the use of fingerprints lies mainly in their uniqueness and distinctiveness, making them crucial for identifying individuals in forensic investigations.
Question 36 Rapport
Which of these is a respiratory organ in mammals?
Détails de la réponse
The organ responsible for respiration in mammals is the lungs. The lungs are located in the chest cavity and are essential for breathing. Here's a simple explanation:
The other options mentioned are not used for respiration in mammals:
Question 37 Rapport
The food nutrient with the highest energy value is
Détails de la réponse
The food nutrient with the highest energy value is lipids, which include fats and oils.
The reason lipids have the highest energy value is due to their chemical structure. They contain long chains of carbon and hydrogen atoms, which can store a significant amount of energy. When these bonds are broken down in the body, they release energy.
In terms of energy measurement, lipids provide about 9 calories per gram, whereas proteins and carbohydrates each provide about 4 calories per gram. Minerals do not provide energy but are essential for other bodily functions.
Therefore, lipids are more energy-dense and offer more energy per gram compared to other nutrients. This is why they are considered the food nutrient with the highest energy value.
Question 38 Rapport
Use the diagram above to answer the question that follows
The diagram demonstrates
Détails de la réponse
Thigmotropism is a directional growth movement which occurs as a mechanosensory response to a touch stimulus. Mechanosensory responses in plants are the ways that plants move or change shape in response to touch, wind, or other mechanical stimuli.
Phototropism is the ability of plants to grow towards or away from light, which is a vital adaptive process for plants.
Geotropism is the growth of the parts of plants in response to the force of gravity.
Hydrotropism is a plant's growth response in which the direction of growth is determined by a stimulus or gradient in water concentration. It is the growth or turning of plant roots towards or away from moisture.
Question 39 Rapport
Which of the following evidences of evolution employs the use of radio-isotope dating?
Détails de la réponse
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.
Question 40 Rapport
An instrument used for measuring the intensity of light
Détails de la réponse
The instrument used for measuring the **intensity of light** is a **photometer**.
Let me explain this in a simple way:
A **photometer** is a device that is specifically designed to measure the **strength or intensity** of light. It helps in determining how bright or dim a light source is. These devices are widely used in various fields such as photography, biology, and astronomy where measuring light intensity is crucial. Photometers can measure different wavelengths of light, including visible light, and sometimes UV or infrared light, depending on the type.
For comparison, let’s briefly learn about the other instruments mentioned:
As you can see, none of these instruments are designed to measure light intensity. Therefore, the correct instrument for measuring the **intensity of light** is the **photometer**.
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