Biology 5 Flashcards
Holozoic nutrition
Holozoic nutrition is a type of nutrition in which organisms ingest complex organic substances, such as other living organisms or their parts, and then digest them internally. This process involves the intake of solid food followed by digestion, absorption of nutrients, and elimination of waste. Holozoic nutrition is commonly observed in animals, including humans, as they consume food items such as plants, animals, and fungi for their nutritional needs.
The airspace in seeds serves several important functions:
Gas Exchange: Airspaces within seeds allow for the exchange of gases, such as oxygen and carbon dioxide, during seed respiration. This helps in the metabolic processes of the seed, such as aerobic respiration, which provides energy for germination.
Moisture Regulation: Airspaces within seeds help regulate moisture levels. They allow for the movement of water vapor, which can help prevent the buildup of excess moisture that could lead to fungal growth or rotting.
Temperature Regulation: Airspaces can also help regulate the internal temperature of seeds, especially during germination. They provide insulation and can help prevent overheating or excessive cooling of the seed embryo.
Seed Dispersal: In some cases, airspaces within seeds may aid in seed dispersal mechanisms. For example, in seeds with adaptations for wind dispersal, airspaces can help make the seeds lighter and more buoyant, allowing them to be carried by the wind over long distances.
The mode of nutrition where digestion is extracellular is called
Saprophytic organisms, such as fungi and certain bacteria, obtain nutrients by decomposing dead organic matter in their environment. They secrete enzymes into the external environment to break down complex organic molecules (such as carbohydrates, proteins, and lipids) present in decaying organic material.
Once the organic matter is broken down into smaller, soluble molecules, the saprophytic organisms absorb these nutrients through their cell walls and membranes for further metabolic processes and energy production. This process of digestion occurring outside the organism’s cells is known as extracellular digestion.
Emergent trees
Emergent trees are found in the uppermost layer of the forest canopy, known as the emergent layer. These trees typically protrude above the main canopy and are often characterized by their large size and broad leaves.
Below the emergent layer, forests generally consist of three main layers:
Canopy Layer: The canopy layer is the primary layer of the forest where the majority of the trees are located. These trees form a dense, continuous layer of foliage that shades the forest floor below. Canopy trees often have broad leaves and dense foliage.
Understory Layer: The understory layer lies beneath the canopy and consists of smaller trees, shrubs, and vegetation that thrive in the partial shade created by the canopy. These plants are adapted to low light conditions and often have smaller leaves compared to canopy trees.
Forest Floor Layer: The forest floor is the lowest layer of the forest, consisting of the ground and the soil beneath the trees. It receives minimal sunlight due to the dense vegetation above, resulting in low levels of plant growth. The forest floor is home to a variety of decomposing organic matter, fungi, insects, and small mammals.
Darwinism
Darwinism refers to the theory of evolution proposed by Charles Darwin in his seminal work “On the Origin of Species” published in 1859. Darwin’s theory of evolution by natural selection suggests that species evolve over time through the process of natural selection, where organisms with advantageous traits are more likely to survive and reproduce, passing on those traits to their offspring.
Lamarckism
Lamarckism, named after the French biologist Jean-Baptiste Lamarck, is a theory of inheritance that proposes that acquired traits can be passed on to offspring. Lamarck suggested that organisms could adapt to their environments during their lifetime, and these adaptations would be inherited by their offspring. However, Lamarckism has been largely discredited in modern biology, as it does not adequately explain the mechanisms of inheritance.
Mendelianism
Mendelianism refers to the principles of inheritance described by Gregor Mendel, an Austrian monk and botanist, in the 19th century. Mendel’s experiments with pea plants led to the discovery of fundamental laws of inheritance, including the principles of dominance, segregation, and independent assortment. Mendelian genetics laid the foundation for modern understanding of inheritance and the laws of heredity.
Naturalism
Naturalism is a philosophical viewpoint that emphasizes the role of natural processes and laws in explaining the world, including the origins and development of life. In the context of biology and evolution, naturalism emphasizes the importance of natural selection and other mechanisms of evolution in shaping the diversity of life on Earth. It is often contrasted with supernatural explanations for the origin and diversity of life.
An estuarine habitat
An estuarine habitat is a partially enclosed coastal body of brackish water with one or more rivers or streams flowing into it, and with a free connection to the open sea. Estuaries are diverse and productive ecosystems that are vital for many species of fish, birds, and other wildlife. They provide important habitats for spawning and nursery grounds for fish, as well as serving as feeding and resting areas for migratory birds. Estuaries also play a crucial role in filtering pollutants from rivers before they reach the ocean and in protecting coastlines from erosion.
While there are some similarities between estuaries and lagoons, they are not the same. Both estuaries and lagoons are coastal water bodies, but they have different characteristics and origins.
An estuary is a partially enclosed coastal body of water where freshwater from rivers and streams mixes with saltwater from the ocean. Estuaries are typically located where rivers meet the sea and can vary in size from small coastal inlets to large bays. They are highly productive ecosystems that support a diverse array of plants, animals, and microorganisms.
On the other hand, a lagoon is a shallow body of water separated from the ocean by a barrier such as a sandbar, barrier island, or coral reef. Lagoons can be found along coastlines, but they are usually more isolated from the open ocean compared to estuaries. Lagoons may contain brackish water (a mix of freshwater and saltwater) or even be entirely freshwater depending on factors such as rainfall, runoff, and groundwater input.
In summary, while both estuaries and lagoons are coastal water bodies, estuaries are characterized by the mixing of freshwater and saltwater and are influenced by tides and river flow, whereas lagoons are typically more isolated from the open ocean and may have varying degrees of salinity.
Edaphic factors refer to the properties of soil that influence plant growth and development. These factors include:
Soil texture: The relative proportions of sand, silt, and clay in the soil affect its water-holding capacity, drainage, and aeration.
Soil structure: The arrangement of soil particles into aggregates affects root penetration, water infiltration, and soil aeration.
Soil pH: The acidity or alkalinity of the soil can influence nutrient availability and microbial activity. Most plants prefer a pH range between 6 and 7, although some species have specific pH requirements.
Soil fertility: The nutrient content of the soil, including essential elements like nitrogen, phosphorus, and potassium, as well as micronutrients, affects plant growth and productivity.
Soil moisture: The amount of water available to plants in the soil affects their ability to uptake nutrients and perform essential physiological processes.
Soil temperature: Soil temperature influences microbial activity, nutrient availability, and root growth. Different plants have different temperature requirements for optimal growth.
Soil aeration: Adequate soil aeration is essential for root respiration and nutrient uptake. Compacted soils or waterlogged conditions can restrict root growth and lead to plant stress.
Estuarine habitats are found in the areas where freshwater rivers or streams meet and mix with saltwater from the ocean. They are characterized by dynamic environmental conditions, including fluctuating salinity levels, tidal currents, and sedimentation. Examples of estuarine habitats include:
Salt marshes: These are coastal wetlands that are flooded and drained by saltwater brought in by the tides. They are dominated by salt-tolerant grasses, sedges, and shrubs, and provide important habitat for birds, fish, and other wildlife.
Mangrove forests: Mangroves are trees and shrubs that grow along tropical and subtropical coastlines in estuarine areas. They have unique adaptations to saline environments, such as aerial roots and salt-excreting glands, and provide valuable habitat for a variety of marine and terrestrial species.
Mudflats: Mudflats are intertidal areas covered with soft, muddy sediment that are exposed at low tide and submerged at high tide. They support a rich community of organisms, including worms, clams, crabs, and shorebirds, and play an important role in nutrient cycling and sediment stabilization.
Tidal creeks and channels: These are narrow, meandering channels that carry water into and out of estuarine areas with the changing tide. They provide habitat for fish, crustaceans, and other aquatic organisms, and serve as important migration corridors for juvenile fish and other marine species.
Estuarine beaches: These are sandy shorelines located within estuaries that are subject to the influence of both freshwater and saltwater. They support a variety of beach-dwelling organisms, such as crabs, clams, and beach plants, and provide nesting habitat for shorebirds and sea turtles.
The relationship between a cattle egret (Bubulcus ibis) and cattle is a symbiotic one known as
The relationship between a cattle egret (Bubulcus ibis) and cattle is a symbiotic one known as mutualism. Cattle egrets often follow large herbivores, such as cattle, and other grazing animals, as they forage for food. They feed on insects and other small prey that are stirred up by the movement of the cattle and also consume parasites, such as ticks and flies, that may be present on the cattle’s skin.
In return, the presence of the cattle provides the egret with easy access to food sources and protection from predators. Cattle disturb insects as they move through grassy areas, making it easier for egrets to catch prey without expending as much energy. Additionally, the presence of the cattle may deter predators that would otherwise target the egrets.
This relationship benefits both the egret and the cattle. The egret gains access to a readily available food source and protection, while the cattle benefit from having the egret help reduce the population of insects and parasites that can negatively affect their health.
Commensalism:
Barnacles on Whales: Barnacles attach themselves to the skin of whales, benefiting by gaining a stable surface for attachment and access to food particles in the water. The whales are not significantly affected by the presence of barnacles.
Remoras and Sharks: Remoras attach themselves to sharks using a modified dorsal fin, feeding on scraps of food left behind by the shark’s meals. The remoras gain protection and access to food, while the shark is not directly harmed by their presence.
Mutualism:
Bees and Flowers: Bees feed on the nectar of flowers while collecting pollen for pollination. The flowers benefit from pollination, allowing them to reproduce, while the bees obtain food.
Lichen: Lichen is a mutualistic association between fungi and algae or cyanobacteria. The algae or cyanobacteria photosynthesize and provide nutrients to the fungus, while the fungus provides protection and absorbs water for the algae or cyanobacteria.
Parasitism:
Ticks and Mammals: Ticks feed on the blood of mammals, attaching themselves to the host and consuming blood for nourishment. The host animal is harmed by the presence of ticks, which can transmit diseases such as Lyme disease.
Tapeworms in Humans: Tapeworms are internal parasites that live in the intestines of humans and other animals. They absorb nutrients from the host’s digestive system, depriving the host of essential nutrients and causing health problems.
Some of the national parks in Nigeria include:
Y ankari National Park
Cross River National Park
Gashaka Gumti National Park
Kainji Lake National Park
Kamuku National Park
Old Oyo National Park
Okomu National Park
Chad Basin National Park
Oba Hills Forest Reserve
Afi Mountain Wildlife Sanctuary
The lack of vascular roots in bryophytes reduces their ability to
The lack of vascular roots in bryophytes reduces their ability to efficiently absorb water from the environment. Unlike plants with vascular tissues, such as ferns and flowering plants, bryophytes rely on simple diffusion to absorb water and nutrients. This limitation can restrict their ability to thrive in drier environments and may lead to reduced growth potential compared to plants with vascular roots.
The vegetative part of a plant
refers to any part of the plant that is involved in vegetative growth and development, excluding reproductive structures. This includes the roots, stems, and leaves. These parts of the plant are primarily responsible for processes such as photosynthesis, nutrient uptake, and structural support.
