1)Name the reagents used to test;
a)Proteins
b)Lipids
c)Vitamin C.
d)Non-reducing sugars.
2)Why is corn oil different from coconut oil.
3)Give 5 adaptations of the leaves to photosynthesis
4)Describe how the following factors affect the rate of photosynthesis;
a)Temperature
b)Carbon(iv)oxide
c)Availability of water
d)Light intensity.
5)Explain why halophytes have pneumatophores.
6)Give 5 adaptations of the red blood cells.
6)Give 4 ways in which leucocytes fight infections.
7)Explain the importance of counter current flow in the fish for gaseous exchange
8)Most carbon is transported to the lungs in the red blood cells,explain the importance of this
9)State two ways in which a person living in high altitude responds to low oxygen concentration
10)Describe how the allergic reactions occur
1)
a) Biuret reagent is used to test for proteins. It turns purple in the presence of proteins.
b) Sudan III reagent is used to test for lipids. It gives a red coloration in the presence of lipids.
c) DCPIP (dichlorophenolindophenol) is used to test for vitamin C. It turns colorless in the presence of vitamin C.
d) Benedict's reagent is used to test for non-reducing sugars. It changes color from blue to green, yellow, or brick-red in the presence of non-reducing sugars.
2) Corn oil and coconut oil are different because they are derived from different sources and have different chemical compositions. Corn oil is extracted from corn kernels, while coconut oil is extracted from coconuts. Corn oil is mainly composed of polyunsaturated fats, while coconut oil is primarily made up of saturated fats. This difference in composition leads to different characteristics, such as their melting points, flavors, and health effects.
3) Five adaptations of leaves for photosynthesis include:
a) Large surface area: Leaves have a broad, flat shape to maximize the surface area available for sunlight capture and gas exchange.
b) Thin structure: Leaves have a thin structure to reduce the distance that light and gases need to travel for efficient photosynthesis.
c) Chloroplasts: Leaf cells contain numerous chloroplasts, which contain the pigment chlorophyll for capturing light energy.
d) Veins: Veins in leaves transport water and nutrients to the cells for photosynthesis and remove waste products.
e) Stomata: Leaves have small openings called stomata, which regulate gas exchange by allowing carbon dioxide to enter and oxygen to exit.
4)
a) Temperature: Photosynthesis is an enzyme-controlled process that is affected by temperature. Optimal temperatures increase the rate of photosynthesis, but excessively high or low temperatures can denature enzymes and inhibit photosynthesis.
b) Carbon dioxide: Carbon dioxide is a reactant in the process of photosynthesis. Higher concentrations of carbon dioxide can increase the rate of photosynthesis until it reaches a saturation point where further increases have no effect.
c) Availability of water: Water is needed for photosynthesis as it is a reactant and is also required to maintain turgor pressure in plant cells. Limited availability of water can slow down or inhibit photosynthesis.
d) Light intensity: Light is the energy source for photosynthesis. Higher light intensities can increase the rate of photosynthesis until the maximum capacity of the plant is reached. Insufficient light can limit photosynthesis.
5) Halophytes are plants that live in highly saline environments, such as salt marshes or mangroves. Pneumatophores are specialized aerial roots that grow above the water's surface and facilitate gaseous exchange in the anaerobic soil typically found in these environments. The pneumatophores allow oxygen to enter the plant's tissues, as the submerged roots may not have access to sufficient oxygen due to the high salt concentration in the soil.
6) Five adaptations of red blood cells include:
a) Biconcave shape: The shape provides a large surface area for the uptake and release of oxygen and carbon dioxide.
b) Lack of nucleus: Red blood cells do not have a nucleus, allowing for more space to carry oxygen and carbon dioxide.
c) High flexibility: Red blood cells can deform to squeeze through narrow capillaries and increase the efficiency of oxygen delivery.
d) Hemoglobin: Red blood cells contain hemoglobin, a protein that binds and transports oxygen.
e) Lifespan: Red blood cells have a lifespan of about 120 days, ensuring a continuous and efficient supply of oxygen throughout the body.
7) Leucocytes fight infections through various mechanisms:
a) Phagocytosis: Some leucocytes, such as macrophages and neutrophils, engulf and destroy pathogens through phagocytosis.
b) Production of antibodies: B-lymphocytes produce antibodies that bind to specific pathogens, marking them for destruction by other immune cells.
c) T-cell activation: T-lymphocytes identify infected cells and release chemicals to kill them directly or activate other immune cells to assist in the destruction of the pathogens.
d) Release of chemical signals: Leucocytes release chemical signals, such as cytokines, to attract other immune cells to the site of infection and coordinate the immune response.
8) Counter current flow in fish allows for efficient gaseous exchange in the gills. It involves the flow of water and blood in opposite directions over the gill surfaces. This arrangement maximizes the diffusion of oxygen from the water into the blood and the diffusion of carbon dioxide from the blood into the water. Counter current flow ensures a constant concentration gradient between the water and blood along the entire length of the gill, maximizing gas exchange efficiency.
9) Two ways a person living in high altitude responds to low oxygen concentration are:
a) Increase in red blood cell production: The body responds to low oxygen levels by producing and releasing more red blood cells, which increases the oxygen-carrying capacity of the blood.
b) Increase in breathing rate: The respiratory system responds to low oxygen levels by increasing the rate and depth of breathing to intake more oxygen and eliminate more carbon dioxide.
10) Allergic reactions occur when the immune system overreacts to harmless substances, known as allergens. The process involves the following steps:
a) Sensitization: During the first exposure to an allergen, the immune system recognizes it as harmful and produces specific antibodies called IgE.
b) Activation of mast cells: Upon subsequent exposure to the allergen, the allergen binds to the IgE antibodies on mast cells, triggering the release of chemical mediators such as histamine and leukotrienes.
c) Inflammatory response: The released chemical mediators cause inflammation, leading to symptoms such as itching, sneezing, runny nose, and inflammation of the airways.
d) Systemic reactions: In severe cases, allergic reactions can lead to anaphylaxis, a systemic allergic response characterized by difficulty breathing, low blood pressure, and potentially life-threatening symptoms.
1) Reagents used to test:
a) Proteins - Biuret reagent
b) Lipids - Sudan IV stain or the grease spot test
c) Vitamin C - DCPIP (dichlorophenolindophenol) solution
d) Non-reducing sugars - Benedict's reagent and hydrochloric acid
2) Corn oil and coconut oil differ in their fatty acid composition. Corn oil is predominantly made up of polyunsaturated fatty acids, while coconut oil primarily consists of saturated fatty acids. This difference in fatty acid structure affects their physical properties, such as melting point, texture, and stability.
3) Adaptations of leaves for photosynthesis:
- Broad surface area to maximize light absorption
- Thin and transparent structure for efficient light transmission
- Chloroplasts containing chlorophyll for capturing light energy
- Veins for water and nutrient transport
- Stomata for gas exchange and regulation of water loss
4) Factors affecting the rate of photosynthesis:
a) Temperature - An increase in temperature generally increases the rate of photosynthesis until it reaches an optimum point, beyond which the enzymes involved in photosynthesis start to denature.
b) Carbon(iv)oxide - Increased availability of carbon dioxide can enhance the rate of photosynthesis, as it is a key reactant in the process.
c) Availability of water - Sufficient water is necessary for photosynthesis, and a lack of water can result in stomatal closure and reduced photosynthetic activity.
d) Light intensity - Higher light intensity generally leads to increased photosynthesis, up to a point where the rate becomes limited by other factors.
5) Halophytes, plants that grow in saline environments, have pneumatophores to aid in gaseous exchange. The pneumatophores are specialized structures that grow above the water or soil surface and have air-filled spaces to facilitate oxygen uptake from the atmosphere.
6) Adaptations of red blood cells:
- Biconcave shape to increase surface area for gas exchange
- Lack of a nucleus to accommodate more hemoglobin and increase oxygen-carrying capacity
- Flexible and deformable cell membrane to fit through narrow capillaries
- High concentration of hemoglobin to efficiently transport oxygen
- Lifespan of approximately 120 days before being recycled by the liver and spleen
7) Ways in which leucocytes fight infections:
- Phagocytosis: Leucocytes engulf and digest foreign particles, such as bacteria and viruses.
- Production of antibodies: Leucocytes, particularly lymphocytes, produce specific antibodies to target and neutralize foreign substances.
- Release of chemical signals: Leucocytes release signaling molecules, such as cytokines, to coordinate immune responses and recruit other immune cells to the site of infection.
- Formation of pus: Leucocytes contribute to the formation of pus, a fluid containing dead cells and tissue debris formed at the site of infection.
8) Counter current flow in fish allows for efficient gaseous exchange by maintaining a concentration gradient along the respiratory surfaces (gills). As water flows across the gill filaments in the opposite direction to blood flow within the filaments, oxygen-rich water continuously encounters oxygen-poor blood, allowing for maximum oxygen uptake by the blood.
9) Most carbon dioxide is transported from body tissues to the lungs in the form of bicarbonate ions (HCO3-) dissolved in plasma. This transport mechanism allows for efficient removal of carbon dioxide from metabolically active tissues and helps maintain acid-base balance in the body.
10) Two ways a person living in high altitude responds to low oxygen concentration:
- Increased breathing rate: The body compensates for low oxygen levels by increasing the rate and depth of breathing, which enhances oxygen uptake.
- Production of more red blood cells: Over time, the body adapts to high altitude by producing more red blood cells, which increases the oxygen-carrying capacity of the blood. This adaptation helps ensure an adequate supply of oxygen to the tissues.