Biology 11 Flashcards
Which subclass of plants show secondary growth
The subclass of plants that typically exhibit secondary growth is the class Magnoliopsida, also known as dicots. These plants have a vascular cambium layer that allows for secondary growth, resulting in the thickening of stems and roots over time. This secondary growth enables dicots to increase in girth and develop woody tissues, contributing to their structural support and longevity. In contrast, plants in the class Liliopsida, or monocots, typically lack secondary growth and do not form woody tissues.
Fungi are considered a distinct group of eukaryotes due to several distinguishing characteristics:
Cell Wall Composition: Fungi have cell walls primarily composed of chitin, a structural polysaccharide, whereas the cell walls of plants are composed mainly of cellulose.Mode of Nutrition: Fungi are heterotrophic organisms, meaning they obtain their nutrients by absorbing organic matter from their environment. They do this through extracellular digestion, secreting enzymes to break down complex organic compounds externally before absorbing the resulting smaller molecules. In contrast, plants are autotrophic, producing their own food through photosynthesis.Absence of Chlorophyll: Unlike plants, fungi lack chlorophyll and are unable to perform photosynthesis. Therefore, they rely on organic matter as a source of carbon and energy.Reproduction: Fungi reproduce both sexually and asexually, often through the production of spores. Their reproductive structures, such as mushrooms or mold spores, are distinct from those of plants.Morphology: Fungi exhibit a wide range of morphological diversity, including unicellular yeast, filamentous molds, and multicellular mushrooms. This diversity sets them apart from plants and other eukaryotic organisms.Overall, these differences in cell structure, nutritional mode, reproductive strategies, and morphology contribute to fungi being recognized as a distinct group within the eukaryotic domain.
Radial Symmetry:
In radial symmetry, body parts are arranged around a central axis, similar to spokes on a wheel. This type of symmetry is commonly found in organisms that are sessile or free-floating in aquatic environments, such as jellyfish, sea anemones, and some types of sea stars.
Bilateral Symmetry:
Bilateral symmetry is characterized by a body plan that can be divided into two equal halves along a single plane, resulting in mirror-image halves. This type of symmetry is prevalent in animals that exhibit cephalization, where sensory organs and nervous tissues are concentrated at the anterior end of the body. Examples include vertebrates (such as mammals, birds, and fish), arthropods (such as insects and crustaceans), and mollusks (such as snails and clams).
Asymmetry
: Asymmetry refers to the absence of any plane of symmetry, resulting in an irregular or uneven body shape. While most animals exhibit some degree of symmetry, certain organisms, such as sponges, exhibit asymmetrical body plans.
Birds share several features with reptiles, indicating their evolutionary relationship. Some of these features include:
Scales: Both birds and reptiles have scales covering their skin. In birds, scales are most noticeable on their legs and feet, while reptiles typically have scales covering their entire body.Amniotic Eggs: Both birds and reptiles lay amniotic eggs, which have protective membranes that prevent desiccation and provide a stable environment for the developing embryo. This adaptation allowed both groups to colonize terrestrial habitats successfully.Feathers and Scales: Feathers, the defining characteristic of birds, are believed to have evolved from scales. The structure of feathers shares similarities with reptilian scales, suggesting a common ancestry.Endothermy: While reptiles are primarily ectothermic (relying on external sources of heat to regulate body temperature), birds exhibit endothermy (the ability to regulate body temperature internally). However, some reptiles, such as certain species of snakes and crocodiles, exhibit behaviors that allow them to regulate body temperature, resembling the thermoregulatory mechanisms observed in birds.Skeletal Features: Birds and reptiles share similarities in their skeletal structure, including the presence of a single middle ear bone (the columella), as well as certain cranial and vertebral characteristics.These shared features provide evidence of the evolutionary relationship between birds and reptiles, with birds being considered descendants of certain groups of ancient reptiles, particularly theropod dinosaurs.
Plant macronutrient
Macronutrients are needed in relatively large quantities and include elements like nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S).
Plant micronutrient
Micronutrients, also known as trace elements, are needed in smaller quantities and include elements like iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), boron (B), molybdenum (Mo), and chlorine (Cl).
Sundew
Actually, sundews are not parasitic. They are carnivorous plants that obtain nutrients by trapping and digesting small insects or other arthropods. They are considered autotrophs because they still perform photosynthesis to produce their own food using sunlight, water, and carbon dioxide. Sundews have specialized leaves covered with glandular hairs that secrete sticky substances to trap prey. Once an insect is caught, the sundew releases enzymes to digest it and absorb the nutrients. This unique adaptation allows sundews to thrive in nutrient-poor environments where they supplement their diet with insects.
Loranthus
Loranthus, commonly known as mistletoe, is a genus of parasitic plants that belong to the family Loranthaceae. These plants are known for their distinctive growth habit of attaching themselves to the branches of trees and shrubs. Loranthus extracts water and nutrients from their host plants, relying on them for support and sustenance. They have small, green leaves and produce clusters of flowers, often with bright colors, which attract pollinators. Mistletoe has cultural significance in various traditions and is sometimes used in holiday decorations, especially during the Christmas season.
Hydrochloric acid (HCl) in the human stomach serves several functions:
- Acidic Environment: HCl creates an acidic environment in the stomach, with a pH of around 2, which is essential for the activation of digestive enzymes and the breakdown of food particles.
- Activation of Pepsinogen: HCl activates the enzyme pepsinogen, converting it into its active form, pepsin. Pepsin is crucial for breaking down proteins into smaller peptides during the process of digestion.
- Killing Pathogens: The acidic environment of the stomach, maintained by HCl, helps in killing ingested bacteria and other pathogens, reducing the risk of infections from contaminated food and water.
- Denaturation of Proteins: HCl helps in the denaturation of dietary proteins, unfolding them and making them more accessible to digestive enzymes for breakdown.
Overall, HCl plays a critical role in the digestive process by creating an optimal environment for the action of digestive enzymes and ensuring effective digestion of food.
hydrochloric acid (HCl) in the stomach can stop the action of
hydrochloric acid (HCl) in the stomach can stop the action of ptyalin, also known as salivary amylase. Ptyalin is an enzyme produced in the salivary glands that helps break down starches into smaller sugars like maltose.
When food enters the stomach, the acidic environment created by HCl can denature ptyalin, reducing its activity. This is one reason why the digestion of starches primarily occurs in the mouth and not in the stomach. Once food leaves the stomach and enters the small intestine, where the pH is less acidic, the action of ptyalin can resume.
Ultrafiltration in the kidney primarily occurs in
Ultrafiltration in the kidney primarily occurs in the renal corpuscles, specifically in the glomerular capillaries within the Bowman’s capsule. The glomerular capillaries are specialized to allow small molecules like water, ions, and waste products to pass through their walls under pressure, while retaining larger molecules like proteins and blood cells. This process results in the formation of the glomerular filtrate, which contains water, ions, glucose, amino acids, and waste products such as urea and creatinine.
Secondary thickening in plants is primarily mediated by
Secondary thickening in plants is primarily mediated by the activity of two meristems: the vascular cambium and the cork cambium. The vascular cambium produces secondary xylem (wood) towards the interior and secondary phloem towards the exterior, contributing to the increase in girth or diameter of the stem or root. The cork cambium, also known as the phellogen, produces cork cells towards the exterior, providing protection and contributing to bark formation.
Orange
An orange is an example of a fruit that develops from a single carpel. It belongs to the category of fruits known as simple fruits, specifically a type called a hesperidium. In an orange, the ovary of a single carpel matures into the fruit containing the seeds, surrounded by a fleshy, leathery rind.
Okra
Okra (okro) - Okra is a vegetable that develops from the ovary of a single carpel, but it is not typically classified as a fruit.
Tomato
- The tomato is also a fruit that develops from the ovary of a single carpel. It is a type of berry known as a “true berry.”
Beans
Bean - Beans are seeds that develop within pods, but they are not typically considered fruits that develop from a single carpel. Instead, they are legumes.
Giberrellin
Gibberellin: Gibberellins are a class of plant hormones that regulate various aspects of plant growth and development, including stem elongation, seed germination, and flowering. They are involved in promoting cell division and elongation, particularly in the stem, and are crucial for the growth of stems and leaves.