1)How is blood pressure generated and maintained in a vein.
2)What is the function of catalase.
3)State the importance of cross pollination of flowering plants.
4)Name any two problems that animal species overcome by their dispersion.
5)What is the role of light energy in autotrophic nutrition in spermatophyte.
6)How is fur important to desert animal other than in their body temperature.
7)What are the functions of named product of white blood cells.
8)Explain three adaptations of cardiac muscles of their function.
9)Define the term resolving power
10)If the student counted 20 cells across the field of view,calculate the size of one cell in micrometres
11)What is tidal volume in ventilation in man
12)Define peristalsis and state its importance in the nutrition of mammals.
13)account for the thick wall and narrow lumen of an artery.
14)How do pathogens that enters the body through the respiratory tract in man prevented from causing diseases.
1) Blood pressure in a vein is generated by the contraction of the surrounding muscles and the rhythmic pumping of the heart. The contraction of the muscles helps to squeeze the vein, pushing the blood forward. The heart's pumping action creates a pressure gradient, causing the blood to flow from areas of higher pressure to lower pressure. Valves present in the veins prevent the backflow of blood, maintaining the pressure.
2) The function of catalase is to catalyze the breakdown of hydrogen peroxide (H2O2) into water and oxygen. This enzyme is present in most living organisms and plays a crucial role in protecting cells from the damage caused by hydrogen peroxide, which is a toxic byproduct of various metabolic processes.
3) Cross pollination in flowering plants is important for genetic diversity. It allows for the exchange of genetic material between different plants, leading to the production of genetically varied offspring. This genetic diversity is essential for adaptation, evolution, and the overall health and survival of plant populations.
4) Two problems that animal species overcome by their dispersion are competition for resources and inbreeding. By dispersing, animals can avoid overcrowding and competition for food, water, and shelter. Dispersion also allows for genetic mixing and reduces the chances of inbreeding, which can lead to reduced genetic diversity and increased susceptibility to diseases.
5) Light energy is essential for autotrophic nutrition in spermatophytes (seed plants) as it is used in the process of photosynthesis. In photosynthesis, light energy is converted into chemical energy in the form of glucose, which is the primary source of energy for the plant. Plants use this glucose for growth, development, and various metabolic processes.
6) Fur is important to desert animals other than regulating body temperature because it provides protection from the intense heat, harsh sunlight, and abrasive desert environment. The fur helps to prevent excessive water loss from the body and acts as insulation against extreme temperature fluctuations. It also helps camouflage the animals in their natural habitat.
7) The named products of white blood cells are antibodies, cytokines, and phagocytes. Antibodies are proteins that help in recognizing and neutralizing foreign substances (antigens) in the body. Cytokines are chemical messengers that regulate the immune response. Phagocytes are cells that engulf and destroy pathogens or foreign particles.
8) Three adaptations of cardiac muscles for their function are:
- Presence of intercalated discs: These specialized cell junctions allow for rapid transmission of electrical signals between cardiac muscle cells, ensuring synchronized contractions of the heart.
- High number of mitochondria: Cardiac muscles require a constant supply of energy to sustain their continuous contractions. The abundance of mitochondria provides the necessary ATP production.
- Strong contraction and fatigue resistance: Cardiac muscles are highly resistant to fatigue and can contract forcefully to pump blood throughout the body continuously.
9) Resolving power refers to the ability of an optical instrument, such as a microscope, to distinguish between two adjacent points or objects as separate entities. It is a measure of the instrument's ability to reveal fine details or resolving fine structures.
10) The size of one cell in micrometers can be calculated by dividing the field of view (FOV) by the number of cells seen across it. If the student counted 20 cells across the FOV, the size of one cell would be the FOV divided by 20.
11) Tidal volume in ventilation refers to the volume of air that is inspired or expired during normal breathing in a resting state. It is the amount of air that moves in and out of the lungs with each breath without any additional effort. Tidal volume is typically around 500 milliliters in an average adult.
12) Peristalsis is the rhythmic contraction and relaxation of muscles in the gastrointestinal tract. It helps in the movement of food through the digestive system. The coordinated contractions of the muscles push the food along in a wave-like motion, allowing for efficient digestion and absorption of nutrients.
13) The thick wall and narrow lumen of an artery are essential for its function. The thick wall is composed of layers of smooth muscle, elastic tissue, and connective tissue, providing strength and support to withstand the high pressure created by the heart's pumping action. The narrow lumen helps to maintain the high pressure and ensure the efficient flow of oxygenated blood to various parts of the body.
14) Pathogens that enter the body through the respiratory tract in man are prevented from causing diseases through various defense mechanisms:
- Coughing and sneezing: These reflex actions help to expel pathogens from the respiratory system and prevent their entry into the body.
- Mucous membranes and cilia: The respiratory tract is lined with mucus-producing cells and tiny hair-like structures called cilia. The mucus traps pathogens, and the cilia move the mucus toward the throat, where it can be coughed out or swallowed.
- Immune response: The respiratory tract has immune cells, such as macrophages, that can engulf and destroy invading pathogens. Additionally, antibodies and other immune factors present in the respiratory system can neutralize or eliminate pathogens.
1) Blood pressure in veins is generated and maintained through a combination of factors. When the heart contracts, it pumps blood into the arteries, creating high pressure. As blood moves away from the heart and into smaller vessels called arterioles, pressure gradually decreases. By the time blood reaches the veins, the pressure is relatively low. Despite this, the following mechanisms help maintain blood pressure in veins:
- Venous valves: Veins have one-way valves that prevent backflow of blood. These valves ensure that blood flows towards the heart, maintaining pressure.
- Smooth muscle contraction: Veins have smooth muscle in their walls. Contraction of this muscle can help squeeze blood towards the heart, aiding in maintaining blood pressure.
- Skeletal muscle pump: The contraction of skeletal muscles during movement compresses nearby veins, forcing blood towards the heart. This assists in maintaining blood pressure.
2) Catalase is an enzyme that plays a crucial role in protecting cells from damage caused by reactive oxygen species (ROS). It catalyzes the decomposition of hydrogen peroxide (H2O2) into water (H2O) and molecular oxygen (O2). This reaction prevents the accumulation of toxic levels of H2O2, which can cause oxidative damage to cells and tissues. Therefore, the primary function of catalase is to protect cells from harmful effects of ROS and maintain cellular homeostasis.
3) Cross pollination in flowering plants is essential for various reasons:
- Genetic diversity: Cross pollination enables the mixing of genetic material between different plants, resulting in offspring with diverse genetic characteristics. This genetic diversity enhances the adaptability and resilience of plant populations to changing environmental conditions.
- Increased seed viability: Cross pollination increases the chances of successful fertilization and seed production. This increases the viability of seeds, ensuring the continuity of plant populations.
- Outbreeding: Cross pollination helps prevent inbreeding, which can lead to genetic abnormalities and reduced fitness in plant populations. By promoting outbreeding, cross pollination enhances the overall health and vitality of plant species.
- Gene flow: Cross pollination allows for the exchange of genetic material between plant populations, promoting gene flow. This gene flow aids in the dispersal of advantageous traits and the colonization of new habitats.
4) Animal species overcome various problems through dispersion, including:
- Avoiding competition: Dispersal helps animals find new territories with fewer competitors for resources such as food, mates, and habitat. This reduces competition pressures and increases their chances of survival.
- Minimizing genetic inbreeding: Dispersal allows animals to move away from their birthplace, reducing the likelihood of mating with closely related individuals. This promotes genetic diversity and reduces the risk of genetic disorders.
- Colonizing new habitats: Dispersal enables animals to colonize new habitats where resources are available and conditions are favorable. This increases their chances of finding suitable living conditions and can lead to the establishment of new populations.
5) Light energy plays a vital role in the process of autotrophic nutrition in spermatophytes (seed plants) through photosynthesis. Photosynthesis is the process by which plants convert light energy into chemical energy in the form of glucose, which is used as a source of energy for growth and metabolism. Light energy is absorbed by pigments called chlorophyll in the chloroplasts of plant cells. This energy is then used to convert carbon dioxide and water into glucose and oxygen during the light-dependent reactions of photosynthesis. Therefore, light energy is crucial for the production of organic molecules that sustain the plant's autotrophic nutrition.
6) In addition to regulating body temperature, fur serves other important functions for desert animals:
- Camouflage: The coloration and pattern of fur can help desert animals blend into their sandy surroundings, providing camouflage and protection from predators.
- Protection against sunlight: Fur can act as a barrier against intense sunlight, shielding the animal's skin from harmful ultraviolet (UV) rays.
- Insulation: While fur can help regulate body temperature, it also acts as insulation by trapping air close to the animal's body. This insulation helps prevent heat loss and keeps the animal warm during cold desert nights.
7) White blood cells produce various substances that serve important functions:
- Antibodies: White blood cells, specifically B lymphocytes, produce antibodies in response to the presence of foreign substances (antigens) such as bacteria or viruses. Antibodies help neutralize and eliminate these antigens, aiding in the body's immune response.
- Cytokines: White blood cells, such as T lymphocytes, produce cytokines, which are signaling molecules that help regulate and coordinate immune responses. Cytokines play a crucial role in activating other immune cells, mediating inflammation, and controlling the immune system's overall response.
- Histamine: Mast cells, a type of white blood cell, release histamine in response to injury or allergic reactions. Histamine is involved in various processes, including inflammation, allergic responses, and blood vessel dilation.
- Interferons: Interferons are proteins produced by white blood cells in response to viral infections. They help inhibit the replication and spread of viruses, thereby limiting the infection's severity.
8) Cardiac muscles have several adaptations that enable them to carry out their function of pumping blood effectively:
- Striated appearance: Cardiac muscle consists of parallel striations due to the arrangement of contractile proteins (actin and myosin). This striated structure allows for coordinated and synchronized contractions of cardiac muscle cells, ensuring efficient pumping of blood.
- Intercalated discs: These are specialized junctions between cardiac muscle cells that facilitate rapid electrical signaling and communication. Intercalated discs ensure that electrical impulses pass quickly from one cell to another, coordinating contraction and promoting efficient pumping of blood.
- High mitochondria content: Cardiac muscle cells have a high density of mitochondria, which are responsible for producing the energy (in the form of ATP) required for muscle contraction. This high mitochondrial content ensures a constant supply of energy for the continuous pumping action of the heart.
9) Resolving power refers to the ability to distinguish between two adjacent points as separate entities in a microscope or imaging system. It is a measure of the smallest resolvable detail that can be observed. The term is often used in microscopy to describe the clarity or level of detail that can be seen in an image. A higher resolving power indicates a finer level of detail and better image resolution.
10) To calculate the size of one cell in micrometers, we need information about the field of view of the microscope. The field of view represents the area visible through the microscope at a specific magnification. If the student counted 20 cells across the field of view, we need to know how many cells span the diameter of the field of view.
11) Tidal volume refers to the amount of air that is inhaled or exhaled during normal, quiet breathing. It represents the volume of air that moves in and out of the lungs with each breath without any effort or forceful breathing. Tidal volume in ventilation in man is typically around 500 ml.
12) Peristalsis is a rhythmic muscular contraction and relaxation that helps propel food along the gastrointestinal tract. It involves waves of muscular contractions that occur in a coordinated manner, pushing food forward. Peristalsis is important for the nutrition of mammals as it ensures the proper movement and mixing of food with digestive enzymes, facilitating digestion and absorption of nutrients. It also helps in the elimination of waste material from the body.
13) Arteries have a thick wall and narrow lumen to fulfill specific functions:
- Thick wall: The walls of arteries contain layers of smooth muscle, elastic fibers, and connective tissue. This thick wall provides structural support and allows arteries to withstand the high pressure generated by blood flow from the heart. The muscular wall also assists in regulating blood flow and pressure by constricting or dilating the arteries.
- Narrow lumen: Arteries have a relatively narrow lumen to maintain blood pressure. The narrow diameter increases the resistance to blood flow, causing blood to be forced along at a higher pressure. This helps ensure a continuous and adequate blood supply to organs and tissues.
14) Pathogens that enter the body through the respiratory tract are prevented from causing diseases through various defense mechanisms:
- Mucus production: The respiratory tract produces mucus, which traps foreign particles, including pathogens. The mucus is then moved upward through the action of cilia, tiny hair-like structures that line the respiratory tract. This helps to trap and remove pathogens, preventing them from reaching the lungs.
- Coughing and sneezing: When the respiratory tract is irritated, coughing and sneezing reflexes are triggered. These actions forcefully expel pathogens, reducing the chances of infection.
- Immune system response: The respiratory tract is lined with immune cells, such as macrophages and lymphocytes, which actively identify and neutralize pathogens. These cells can recognize and destroy pathogens before they can cause disease.
- IgA antibodies: The respiratory tract produces a specific type of antibody called IgA. These antibodies can bind to and neutralize pathogens, preventing them from infecting the respiratory epithelium.
Additionally, factors like vaccination, good hygiene practices (such as regular handwashing), and a healthy lifestyle can also help prevent pathogens from causing diseases in the respiratory tract.