Biology 14 Flashcards
Nitrogen fixation and thunderstorms
Certainly! Thunderstorms can contribute to the enrichment of soil through a process called atmospheric nitrogen fixation. Here’s how it works:Atmospheric Nitrogen: The Earth’s atmosphere is composed mainly of nitrogen gas (N2), which makes up about 78% of the air we breathe.Nitrogen Fixation: Lightning, which occurs during thunderstorms, has enough energy to split nitrogen molecules in the air (N2) into individual nitrogen atoms (N). This process is called nitrogen fixation.Formation of Nitrogen Oxides: The individual nitrogen atoms (N) produced by lightning quickly combine with oxygen molecules (O2) in the atmosphere to form nitrogen oxides (NOx), such as nitrogen dioxide (NO2) and nitric oxide (NO).Dissolving in Rainwater: Nitrogen oxides are water-soluble and dissolve in rainwater, forming nitric acid (HNO3) and nitrous acid (HNO2).Nitrate Formation: Nitric acid and nitrous acid react with water and other substances in the atmosphere to form nitrates (NO3-), which are soluble in water.Nutrient Delivery: When it rains, the nitrogen-containing compounds, including nitrates, are carried down to the soil by rainfall. These nitrates serve as a source of nitrogen, an essential nutrient for plant growth.Soil Enrichment: Once in the soil, nitrates are readily absorbed by plant roots and utilized for various metabolic processes, including protein synthesis and growth. This enrichment of the soil with nitrogen helps to support plant growth and contributes to the overall fertility of the soil.Overall, thunderstorms play a crucial role in the natural nitrogen cycle by converting atmospheric nitrogen into a form that can be utilized by plants, thereby contributing to soil fertility and ecosystem productivity.
Heating soil up
The experiment you described is likely aimed at determining the organic matter content in the soil. When soil is heated, organic matter such as dead plant material, microbes, and other organic substances will burn off at different temperatures.
Heating till Red Hot: This step burns off any organic matter present in the soil, leaving behind inorganic materials such as minerals and ash.
Further Heating till No Smoke: Once the organic matter has burned off, further heating ensures that all volatile organic compounds have been driven off, leaving behind only the inorganic components.
By measuring the weight loss of the soil sample before and after heating, scientists can calculate the percentage of organic matter in the soil. This information is important for understanding soil fertility, nutrient cycling, and overall soil health.
Anopheles mosquito
Key points about Anopheles mosquito metamorphosis include:
1. Complete Metamorphosis: Like other mosquito species, Anopheles mosquitoes undergo complete metamorphosis, consisting of four stages: egg, larva, pupa, and adult. 2. Egg Stage: Female Anopheles mosquitoes lay eggs individually on the surface of freshwater bodies, typically in areas with still or slow-moving water. 3. Larval Stage: Anopheles mosquito larvae hatch from the eggs and live in water, feeding on organic matter and microorganisms. They have a distinct head and abdomen, with specialized structures for breathing underwater, including a siphon. 4. Pupal Stage: Larvae molt into pupae, which are comma-shaped and non-feeding. During this stage, they undergo dramatic physiological changes, preparing for emergence as adults. 5. Adult Stage: After several days as pupae, adult Anopheles mosquitoes emerge from the water. They rest on nearby vegetation until their exoskeleton hardens, then fly away to find mates and feed on nectar or blood. 6. Disease Transmission: Anopheles mosquitoes are vectors for malaria, a potentially deadly disease caused by Plasmodium parasites. Female Anopheles mosquitoes require a blood meal to develop their eggs, and during feeding, they can transmit the malaria parasite to humans. 7. Control Strategies: Understanding the life cycle of Anopheles mosquitoes is crucial for implementing effective control measures to reduce mosquito populations and prevent malaria transmission. This includes methods such as habitat modification, insecticide application, and the use of mosquito nets and repellents to protect against bites.
blue cobalt chloride paper
, can also be used to detect water loss from a leaf. Cobalt chloride paper is blue when hydrated and turns pink when it loses water, making it a useful indicator of moisture levels. By placing the blue cobalt chloride paper under a leaf, the paper will turn pink as it absorbs water lost through transpiration. This color change can be visually observed and quantified to measure the rate of water loss from the leaf.
Yam plant storage
In a yam plant, carbohydrates are primarily stored in the stem, particularly in the form of starch. The tubers, which are swollen underground stems, serve as the main storage organs for carbohydrates. Therefore, the correct answer is “stem.”
Common plants that store food in their buds include:
- Onion (Allium cepa): Onions store nutrients in their bulb, which is a modified underground bud consisting of layers of modified leaves.
- Garlic (Allium sativum): Similar to onions, garlic stores nutrients in its bulb, which is also a modified underground bud composed of layers of modified leaves.
- Potato (Solanum tuberosum): Potatoes store nutrients in their underground tubers, which are essentially enlarged underground stems or buds. These tubers serve as a storage organ for carbohydrates.
- Ginger (Zingiber officinale): Ginger stores nutrients in its rhizomes, which are underground stems or modified buds. These rhizomes contain starches and other nutrients.
- Lily (Lilium spp.): Lilies store nutrients in their bulbs, which are underground storage organs formed from modified buds. These bulbs contain stored carbohydrates and other nutrients to support the growth of the plant.
These are just a few examples of common plants that store food in their buds.
Common plants that store food in their adventitious roots include:
- Sweet Potato (Ipomoea batatas): Sweet potatoes store nutrients in their enlarged, fleshy adventitious roots, which are often referred to as tuberous roots. These roots contain stored carbohydrates, particularly starches, which serve as an energy reserve for the plant.
- Carrot (Daucus carota): Carrots store nutrients in their taproots, which are thickened, fleshy roots that store sugars and other carbohydrates. These roots serve as an energy reserve for the plant.
- Beetroot (Beta vulgaris): Beetroot stores nutrients in its swollen taproot, which is rich in sugars, particularly sucrose. This taproot serves as a storage organ for carbohydrates.
- Radish (Raphanus sativus): Radishes store nutrients in their enlarged, fleshy taproots, which contain carbohydrates, including sugars and starches. These taproots serve as an energy reserve for the plant.
- Turnip (Brassica rapa subsp. rapa): Turnips store nutrients in their enlarged, fleshy taproots, which contain carbohydrates, primarily starches. These taproots serve as an energy reserve for the plant.
Common plants that store food in their leaves include:
- Aloe Vera (Aloe barbadensis): Aloe vera stores water and nutrients in its thick, fleshy leaves. These leaves contain a gel-like substance rich in carbohydrates, particularly polysaccharides, which serve as an energy reserve for the plant.
- Succulents (e.g., Jade Plant, Snake Plant): Many succulent plants store water and nutrients in their thick, fleshy leaves. These leaves are adapted to store moisture and often contain carbohydrates and other nutrients that serve as energy reserves.
- Cacti (e.g., Prickly Pear, Saguaro): Cacti store water and nutrients in their succulent stems and leaves. The fleshy pads or segments of cacti contain stored carbohydrates, particularly sugars and starches, which serve as energy reserves.
- Agave (Agave spp.): Agave plants store carbohydrates, primarily in the form of fructans, in their thick, fleshy leaves. These carbohydrates serve as an energy reserve for the plant and are harvested to produce agave syrup.
- Ornamental Plants (e.g., Bromeliads, Kalanchoe): Some ornamental plants store water and nutrients in their leaves. For example, bromeliads store water in their central rosette of leaves, while kalanchoe plants store water and nutrients in their fleshy leaves.
Several plants have the ability to propagate from leaves, either through natural processes or by human intervention. Here are some common examples:
- African Violet (Saintpaulia spp.): African violets can be propagated from leaf cuttings. A healthy leaf with a short stem is cut from the parent plant and placed in a moist growing medium. Adventitious roots develop from the leaf’s base, and a new plantlet forms at the leaf’s edge.
- Jade Plant (Crassula ovata): Jade plants can be propagated from leaf or stem cuttings. Leaves or stem segments are allowed to callus for a few days before being placed in well-draining soil. Roots and new shoots develop from the callused areas, leading to the growth of new plants.
- Snake Plant (Sansevieria spp.): Snake plants can be propagated from leaf cuttings. Leaves are cut into sections, and each section is planted in soil. New shoots and roots emerge from the cut ends of the leaf sections, giving rise to new plants.
- Succulents (Various genera): Many succulent plants, including various types of Echeveria, Sedum, and Kalanchoe, can be propagated from individual leaves. Leaves are carefully removed from the parent plant and laid on top of well-draining soil. Roots and new rosettes or plantlets develop from the base of the leaf, eventually forming new plants.
- Begonia (Various species): Some begonia species can be propagated from leaf cuttings. Healthy leaves are cut from the parent plant and placed on top of moist soil or in a tray of water. Adventitious roots and new shoots develop from the leaf’s base, leading to the formation of new plants.
Grasshoppers
: Grasshoppers undergo incomplete metamorphosis, which means they have three stages: egg, nymph, and adult. The nymphs look like smaller versions of the adults but lack wings. As they grow, they molt several times, gradually developing wings and sexual organs until they reach adulthood.
Bees
: Bees undergo complete metamorphosis, which consists of four stages: egg, larva, pupa, and adult. The egg hatches into a larva, which is fed by worker bees. The larva then undergoes pupation, during which it transforms into an adult bee inside a cocoon-like structure called a cell. The adult bee emerges from the cell and undergoes further development before becoming sexually mature.
Termites
: Termites also undergo incomplete metamorphosis. They have three stages: egg, nymph, and adult. The nymphs resemble smaller versions of the adults but lack fully developed reproductive organs. As they mature, they molt and gradually develop wings and reproductive capabilities.
The liver regulates blood sugar through several mechanisms:
- Glycogen Storage and Release: The liver stores excess glucose in the form of glycogen when blood sugar levels are high, such as after a meal. When blood sugar levels drop, the liver breaks down glycogen into glucose and releases it into the bloodstream to maintain normal blood sugar levels.
- Gluconeogenesis: The liver can also produce glucose from non-carbohydrate sources, such as amino acids and glycerol, through a process called gluconeogenesis. This helps maintain blood glucose levels during fasting or periods of low carbohydrate intake.
- Glycogenolysis: In addition to releasing glucose from glycogen stores, the liver can also break down glycogen directly into glucose through a process called glycogenolysis. This provides a rapid source of glucose when needed, such as during exercise or periods of stress.
- Insulin and Glucagon Regulation: The liver responds to hormonal signals from insulin and glucagon to regulate blood sugar levels. Insulin promotes glucose uptake by cells and inhibits glycogen breakdown in the liver, while glucagon stimulates glycogen breakdown and glucose release from the liver when blood sugar levels are low.
Overall, the liver plays a central role in maintaining blood sugar homeostasis by balancing glucose production and utilization in response to dietary intake, hormonal signals, and metabolic demands.
Liver stores iron
Yes, the liver stores iron. One of the liver’s functions is to regulate the levels of iron in the body. It stores excess iron absorbed from the diet and releases it when needed. Iron is an essential mineral that plays a crucial role in various bodily functions, including oxygen transport, energy production, and DNA synthesis. The liver helps maintain iron balance by storing excess iron in a form called ferritin and releasing it into the bloodstream as needed. However, excessive accumulation of iron in the liver can lead to conditions such as hemochromatosis, a disorder characterized by iron overload.
Liver regulate blood sugar
Yes, the liver plays a crucial role in regulating blood sugar levels. It helps maintain blood glucose within a narrow range, which is essential for providing energy to the body’s cells and ensuring overall metabolic balance.The liver regulates blood sugar through several mechanisms:Glycogen Storage and Release: The liver stores excess glucose in the form of glycogen when blood sugar levels are high, such as after a meal. When blood sugar levels drop, the liver breaks down glycogen into glucose and releases it into the bloodstream to maintain normal blood sugar levels.Gluconeogenesis: The liver can also produce glucose from non-carbohydrate sources, such as amino acids and glycerol, through a process called gluconeogenesis. This helps maintain blood glucose levels during fasting or periods of low carbohydrate intake.Glycogenolysis: In addition to releasing glucose from glycogen stores, the liver can also break down glycogen directly into glucose through a process called glycogenolysis. This provides a rapid source of glucose when needed, such as during exercise or periods of stress.Insulin and Glucagon Regulation: The liver responds to hormonal signals from insulin and glucagon to regulate blood sugar levels. Insulin promotes glucose uptake by cells and inhibits glycogen breakdown in the liver, while glucagon stimulates glycogen breakdown and glucose release from the liver when blood sugar levels are low.Overall, the liver plays a central role in maintaining blood sugar homeostasis by balancing glucose production and utilization in response to dietary intake, hormonal signals, and metabolic demands.
Budding:
• Yeast: Yeast is a single-celled fungus that reproduces asexually by budding. A small bud forms on the parent cell, grows in size, and eventually separates to become a new individual.
• Hydra: Hydra is a freshwater organism belonging to the phylum Cnidaria. It reproduces asexually by budding, where small buds develop on the body wall of the parent organism and eventually detach to form new individuals.
Multiple Fission:
• Plasmodium: Plasmodium species are parasites that cause malaria in humans. During the asexual phase of their life cycle, Plasmodium undergoes multiple fission, where the nucleus divides multiple times within the cell before the cell divides into multiple daughter cells called merozoites.
Budding and Binary Fission:
• Amoeba: Amoeba is a single-celled protist that can reproduce both sexually and asexually. It reproduces asexually by binary fission, where the cell divides into two daughter cells. Additionally, under certain conditions, amoeba can also reproduce by budding, where a smaller daughter cell forms as an outgrowth from the parent cell.
Fragmentation
Fragmentation is a form of asexual reproduction in which an organism breaks into fragments, each of which develops into a new individual. This process is common in certain types of organisms, especially those with simple body structures or lacking specialized reproductive organs. Here are some examples:
1. Fungi: • Rhizopus: Rhizopus is a genus of fungi commonly known as bread molds. They reproduce asexually through fragmentation, where hyphae (filamentous structures) break into fragments, each of which can grow into a new organism under suitable conditions. 2. Algae: • Spirogyra: Spirogyra is a filamentous green algae that reproduces asexually by fragmentation. Portions of the filament break off and develop into new individuals, with each fragment capable of growing into a new filament under favorable environmental conditions. 3. Plants: • Bryophytes: Some mosses and liverworts reproduce asexually by fragmentation. Portions of the parent plant break off and grow into new individuals when favorable conditions are present. 4. Animals: • Planarians: Planarians are flatworms that can reproduce asexually by fragmentation. If a planarian is cut into pieces, each piece has the ability to regenerate into a complete individual, making fragmentation a form of reproduction in these organisms. 5. Sponges: • Sponges (Porifera) can reproduce asexually through fragmentation. If a sponge is broken into pieces, each piece has the potential to develop into a new individual sponge through regeneration.
Klinostat
: A klinostat is a device used in plant biology to study gravitropism, which is the response of plants to gravity. It consists of a rotating platform on which plants are placed. By rotating the platform at a constant speed, the klinostat prevents the plants from perceiving the direction of gravity, allowing researchers to study the effects of gravity on plant growth and development.
Manometer
: A manometer is a device used to measure pressure, typically the pressure of gases or liquids. It consists of a U-shaped tube partially filled with a liquid (such as mercury or water). The difference in height between the two arms of the U-tube indicates the pressure difference between the two points being measured.
Porometer:
A porometer is an instrument used to measure the rate of water loss or transpiration from the leaves of plants. It works by measuring the rate at which water vapor diffuses through small pores (stomata) on the surface of the leaf. Porometers are commonly used in plant physiology research to assess plant water stress and evaluate plant water use efficiency.
Photometer
: A photometer is a device used to measure the intensity of light or other electromagnetic radiation. It typically consists of a sensor or detector that measures the amount of light reaching it. Photometers are used in various fields, including photography, astronomy, environmental monitoring, and optics, to quantify the brightness or intensity of light sources.
The rate of transpiration of a leafy shoot is generally highest under the following conditions:
High Light Intensity: Transpiration rates increase with higher light intensity because photosynthesis, which occurs in the presence of light, drives the opening of stomata. This allows for greater water loss through transpiration.
2. High Temperature: Warmer temperatures increase the rate of evaporation of water from the leaf surface, leading to higher transpiration rates. This is because higher temperatures increase the vapor pressure deficit between the leaf and the surrounding air, promoting greater water loss.
3. Low Humidity: Transpiration rates are higher in drier air because the vapor pressure deficit between the leaf surface and the surrounding air is greater, facilitating faster water loss from the leaf.
4. High Air Movement (Wind): Increased air movement around the leaf, such as windy conditions, can enhance transpiration rates by removing the boundary layer of humid air surrounding the leaf, which slows down water vapor diffusion from the leaf surface.
The two main types of human tapeworms are Taenia solium (pork tapeworm) and Taenia saginata (beef tapeworm). These tapeworms can be distinguished by several characteristics:
- Host Species: Taenia solium primarily infects humans who consume undercooked pork contaminated with cysts containing the tapeworm larvae. Taenia saginata, on the other hand, primarily infects humans who consume undercooked beef contaminated with cysts containing the tapeworm larvae.
- Size and Shape: While both tapeworms have a long, ribbon-like body composed of multiple segments called proglottids, they can be distinguished by differences in size and shape. Taenia solium tends to be smaller, with adults typically measuring 2-7 meters in length, while Taenia saginata is larger, with adults often reaching lengths of 4-10 meters.
- Number of Hooks: Taenia solium has hooks on the scolex (the attachment organ at the front end of the tapeworm), which it uses to attach to the intestinal wall. These hooks are absent in Taenia saginata.
- Uterine Branching: In Taenia solium, the uterus has fewer branches compared to Taenia saginata. The proglottids of Taenia solium typically have a single uterine branch, while those of Taenia saginata have multiple branches
Respiratory organ of crabs
Crabs and other crustaceans have gills as their respiratory organs. Gills are feathery structures located in the branchial chamber, which is typically located under the carapace (the hard upper shell) or on the sides of the crab’s body. Gills are responsible for extracting oxygen from water and releasing carbon dioxide, allowing the crab to breathe underwater.