Biology 13 Flashcards
Wind vane measures
Wind direction
Homoiothermic
”” refers to organisms that can maintain a relatively constant body temperature regardless of external environmental conditions. These organisms are also known as “warm-blooded.” Mammals and birds are classic examples of homoiothermic animals. They regulate their internal body temperature through physiological mechanisms such as metabolic heat production, insulation (e.g., fur, feathers), and behavioral adaptations (e.g., seeking shade or sun). This ability to regulate body temperature allows homoiothermic animals to maintain optimal metabolic function and activity levels in a wide range of environmental conditions.
Hypogeal Germination:
• In hypogeal germination, the cotyledons (seed leaves) remain below the soil surface after germination.
• The embryonic stem, called the hypocotyl, elongates and pushes the cotyledons upward, while the epicotyl (portion of the stem above the cotyledons) remains short.
• The cotyledons may stay enclosed within the seed coat or emerge partially, but they do not emerge fully above the soil surface.
• Examples of plants with hypogeal germination include beans, peas, and sunflowers.
Epigeal Germination:
• In epigeal germination, the cotyledons emerge above the soil surface after germination.
• The embryonic stem, called the hypocotyl, elongates and raises the cotyledons and epicotyl above the soil surface.
• The cotyledons become photosynthetic and green as they are exposed to light.
• The epicotyl grows to form the stem, and the first true leaves develop above the cotyledons.
• Examples of plants with epigeal germination include tomatoes, cucumbers, and mustard.
Halophyte
A halophyte is a type of plant that can tolerate high levels of salinity (salt) in the soil or water where it grows. These plants have adapted to thrive in environments such as salt marshes, coastal areas, and saline deserts where salt concentrations are high. Halophytes have developed various physiological and biochemical mechanisms to cope with salt stress, such as the ability to excrete salt through specialized glands, store excess salt in vacuoles, or tolerate high levels of salt within their cells. Some examples of halophytes include mangroves, salt-tolerant grasses, and certain species of succulents and shrubs. These plants play important ecological roles in stabilizing coastal habitats, preventing soil erosion, and providing habitat and food for wildlife in saline environments.
Biceps
Biceps Muscle:
1. Location: The biceps brachii muscle is located in the upper arm and spans from the shoulder to the elbow. 2. Structure: It is a two-headed muscle, consisting of a long head and a short head, which join together to form a single muscle belly. 3. Function: The primary function of the biceps is to flex the elbow joint, bringing the forearm towards the upper arm. 4. Secondary Functions: The biceps also assist in supinating the forearm (rotating it so the palm faces upwards) and stabilizing the shoulder joint. 5. Exercises: Common exercises that target the biceps include bicep curls, chin-ups, and hammer curls.
Triceps
Triceps Muscle:
1. Location: The triceps brachii muscle is located in the back of the upper arm and spans from the shoulder to the elbow. 2. Structure: It is a three-headed muscle, consisting of a long head, a lateral head, and a medial head. 3. Function: The primary function of the triceps is to extend the elbow joint, straightening the arm. 4. Secondary Functions: The triceps also assist in shoulder extension (moving the arm backwards) and shoulder stabilization. 5. Exercises: Common exercises that target the triceps include tricep dips, tricep pushdowns, and skull crushers.
Element that is essential for coagulation
Calcium
I neural spine
II centrum
III transverse process
Iv neural canal
V metapophysis
Sporangium
Sporangium:
1. Definition: A sporangium is a structure found in plants, fungi, and some protists that produces and contains spores. 2. Function: The primary function of a sporangium is to produce spores through a process called sporogenesis. 3. Location: Sporangia are typically found on specialized structures such as sporophytes in plants or sporocarps in fungi. 4. Dispersal: Spores produced by sporangia are released into the environment and can be dispersed by wind, water, or other means. 5. Reproduction: Spores germinate and develop into new individuals through the process of germination and subsequent growth.
Antheridium
Antheridium:
1. Definition: An antheridium is a structure found in some plants, algae, and fungi that produces and releases male gametes, or sperm cells. 2. Structure: An antheridium is typically a small, flask-shaped structure containing numerous sperm-producing cells called spermatogenous cells. 3. Function: The primary function of an antheridium is to produce and release sperm cells, which are essential for fertilization. 4. Location: Antheridia are often found on the gametophyte (sexual phase) generation of plants, algae, and fungi. 5. Fertilization: Sperm cells released from antheridia swim to the vicinity of an archegonium (female reproductive structure) to fertilize egg cells.
Archegonium
Archegonium:
1. Definition: An archegonium is a structure found in some plants, algae, and bryophytes that produces and contains female gametes, or egg cells. 2. Structure: An archegonium typically consists of a bulbous base called the venter, which contains the egg cell, and a slender neck that protrudes above the surface of the plant. 3. Function: The primary function of an archegonium is to produce and protect the egg cell, which is necessary for sexual reproduction. 4. Location: Archegonia are often found on the gametophyte generation of plants, algae, and bryophytes. 5. Fertilization: After the release of sperm cells from antheridia, they swim to the vicinity of an archegonium and fertilize the egg cell, initiating the development of a new sporophyte generation.
Prothallus
Definition: A prothallus is a small, green, heart-shaped structure found in ferns and some other vascular plants during the gametophyte stage of their life cycle.
2. Structure: A prothallus is typically one cell layer thick and contains both antheridia (male reproductive structures) and archegonia (female reproductive structures).
3. Function: The primary function of a prothallus is to produce sperm and egg cells and facilitate the fertilization process, leading to the formation of a new sporophyte generation.
4. Habitat: Prothalli are often found growing on moist soil or other damp surfaces in shaded areas, where conditions are favorable for germination and growth.
5. Transient Stage: The prothallus stage is a transient phase in the life cycle of ferns, lasting only until fertilization occurs and a new sporophyte develops from the fertilized egg cell.
Labelled diagram of DNA
Yeast expansion
Yeast is a single-celled fungus that plays a crucial role in breadmaking by causing dough to rise. Yeast produces carbon dioxide gas through a process called fermentation, which helps leaven the dough and creates air pockets that result in a light and airy texture in the finished bread. Here’s how yeast makes flour rise:Activation: Dry yeast is typically activated by mixing it with warm water and a small amount of sugar. The sugar provides food for the yeast, and the warm water activates it, causing the yeast cells to become active and start growing.Fermentation: Once activated, yeast begins to feed on the sugars present in the dough. During this process, yeast metabolizes sugars through fermentation, producing carbon dioxide gas and alcohol as byproducts. The carbon dioxide gas forms bubbles within the dough, causing it to expand and rise.Dough Expansion: As the yeast continues to ferment and produce carbon dioxide gas, the dough gradually expands and rises. The gluten network in the dough traps the gas bubbles, creating a light and airy structure.Proofing: After the dough has risen sufficiently, it is typically allowed to rest and undergo further fermentation, a process known as proofing. During proofing, the yeast continues to produce carbon dioxide gas, further increasing the volume and improving the texture of the bread.Baking: Finally, the dough is baked in an oven, where the high temperature causes the yeast to die and the alcohol to evaporate. The heat also expands the gas bubbles further and sets the structure of the bread, resulting in a fully risen and baked loaf.In summary, yeast makes flour rise by fermenting sugars in the dough, producing carbon dioxide gas, which causes the dough to expand and rise. This process of fermentation and gas production is essential for creating the light and airy texture of bread.
Tests for Reducing Sugars:
- Benedict’s Test: Benedict’s reagent, which contains copper(II) ions, is added to the sample and heated. Reducing sugars, such as glucose and fructose, react with the copper ions in the reagent, reducing them to copper(I) ions. This results in the formation of a colored precipitate (usually green, yellow, orange, or red), indicating the presence of reducing sugars.
- Fehling’s Test: Similar to Benedict’s test, Fehling’s reagent is used to detect reducing sugars. Fehling’s reagent consists of two separate solutions: solution A (aqueous copper(II) sulfate) and solution B (sodium potassium tartrate dissolved in sodium hydroxide). When mixed with the sample and heated, reducing sugars react with the copper ions in solution A, forming a red-brown precipitate of copper(I) oxide.
Tests for Non-Reducing Sugars:
- Hydrolysis followed by Benedict’s or Fehling’s Test: Non-reducing sugars, such as sucrose (table sugar), can be hydrolyzed into their constituent monosaccharides (e.g., glucose and fructose), which are reducing sugars. This can be achieved by adding dilute acid (e.g., hydrochloric acid) to the sample and heating it to hydrolyze the glycosidic bonds. After hydrolysis, the resulting solution can be tested using Benedict’s or Fehling’s test to detect the presence of reducing sugars.
- Tollen’s Test (Silver Mirror Test): Tollen’s reagent, which contains silver ions in an alkaline solution, is added to the sample and heated. Non-reducing sugars, such as sucrose, do not react directly with Tollen’s reagent. However, if the non-reducing sugar is first hydrolyzed into reducing sugars (e.g., glucose) using acid hydrolysis, the reducing sugars formed can react with Tollen’s reagent to reduce the silver ions, resulting in the formation of a silver mirror on the inside of the test tube.
Erepsin
Erepsin is an enzyme involved in the digestion of proteins and peptides in the small intestine. Here are some key points about erepsin:
1. Location: Erepsin is primarily found in the brush border membrane of the epithelial cells lining the small intestine, particularly in the jejunum and ileum. 2. Function: Erepsin is responsible for the final stage of protein digestion, specifically the hydrolysis of peptide bonds. It catalyzes the breakdown of small peptides into individual amino acids, which can then be absorbed by the intestinal epithelial cells and transported into the bloodstream for use by the body. 3. Specificity: Erepsin is highly specific for peptide bonds involving specific amino acids, such as those containing basic or aromatic amino acids like lysine, arginine, and phenylalanine. 4. Optimal pH: Erepsin functions optimally at a slightly alkaline pH, typically around pH 7 to 8, which is the pH range found in the small intestine. 5. Role in Absorption: By breaking down peptides into individual amino acids, erepsin plays a crucial role in facilitating the absorption of nutrients in the small intestine. Once absorbed, amino acids can be used for protein synthesis, energy production, and various metabolic processes throughout the body. 6. Cooperation with Other Enzymes: Erepsin works in conjunction with other digestive enzymes, such as pepsin (in the stomach) and pancreatic proteases (from the pancreas), to ensure the efficient digestion and absorption of dietary proteins.
Overall, erepsin is an essential enzyme involved in the final stages of protein digestion, contributing to the breakdown of peptides into absorbable amino acids in the small intestine.
Proteins is converted to peptones
Pepsin
Peptones converted to polypeptides
Trypsin
Endospermous seed
Key Points:
Endospermous seeds are seeds that contain an endosperm, a tissue rich in nutrients that serves as a food reserve for the developing embryo. Here are some key points and examples of endospermous seeds:
1. Nutrient Storage: Endosperm serves as a storage tissue for nutrients such as carbohydrates, proteins, and lipids, which are essential for the growth and development of the embryo. 2. Triploid Tissue: In most angiosperms, the endosperm is triploid, meaning it contains three sets of chromosomes. It is formed by the fusion of a sperm cell with two polar nuclei during double fertilization. 3. Absorption by Embryo: As the embryo develops, it absorbs nutrients from the endosperm to fuel its growth and development until it can photosynthesize or obtain nutrients from the environment independently. 4. Variability: Endosperm composition can vary among different plant species and even within the same species, depending on factors such as seed size, nutrient requirements, and germination conditions.
Examples of Endospermous Seeds:
Examples of Endospermous Seeds:
1. Maize (Corn): Maize seeds contain a large endosperm that provides nourishment to the developing embryo. The endosperm is primarily composed of starch granules and proteins. 2. Wheat: Wheat seeds also have endospermous seeds, which are rich in starch and gluten proteins. These seeds are widely used for making flour, bread, pasta, and other food products. 3. Rice: Rice seeds contain endosperm that is rich in carbohydrates, particularly starch. It is the primary source of nutrition for the developing rice embryo. 4. Coconut: Coconut seeds have a thick, liquid endosperm known as coconut water, which provides nourishment to the developing embryo. The endosperm solidifies as the coconut matures, forming the white flesh that we commonly eat. 5. Barley: Barley seeds have a starchy endosperm that is used in brewing beer and making malt extracts. The endosperm contributes to the flavor, color, and fermentable sugars in the final product.
Fibrous Joints:
Fibrous Joints:
• These joints are connected by dense fibrous connective tissue.
• Examples include:
• Sutures: Found in the skull, where adjacent bones are tightly fused together.
• Syndesmoses: Found between the radius and ulna in the forearm and the tibia and fibula in the lower leg, where ligaments connect the bones.
Cartilaginous Joints:
• These joints are connected by cartilage.
• Examples include:
• Synchondroses: Found in the growing long bones of children, where hyaline cartilage connects the epiphysis to the diaphysis.
• Symphyses: Found between the vertebrae in the spine and the pubic symphysis, where fibrocartilage connects the bones.
Synovial Joints:
• These joints are characterized by a joint cavity filled with synovial fluid and surrounded by a joint capsule.
• Examples include:
• Hinge Joints: Found in the elbow and knee, allowing movement in one plane (flexion and extension).
• Ball-and-Socket Joints: Found in the shoulder and hip, allowing movement in multiple planes (flexion, extension, abduction, adduction, and rotation).
• Pivot Joints: Found between the radius and ulna in the forearm and between the atlas and axis in the neck, allowing rotational movement.
• Gliding Joints: Found between the carpal and tarsal bones, allowing sliding or gliding movements.
• Saddle Joints: Found in the thumb, allowing movement in two planes (flexion, extension, abduction, adduction, and opposition).
Succession refers to the gradual and predictable process of change in the composition and structure of biological communities over time. Here are key points about succession:
- Primary Succession: This occurs in an area that has not been previously colonized by living organisms, such as bare rock, lava flows, sand dunes, or newly formed land surfaces like volcanic islands or glacial moraines.
- Secondary Succession: This occurs in an area that has been previously inhabited by living organisms but has undergone disturbance, such as forest fires, floods, hurricanes, or human activities like logging or agriculture.
Diagram of flower
Cocci
Cocci (Spherical):
• Cocci are spherical or round-shaped bacteria.
• Examples include Streptococcus, Staphylococcus, and Neisseria species.
• Cocci can occur singly, in pairs (diplococci), in chains (streptococci), or in clusters (staphylococci).
• Cocci are often associated with diseases such as pneumonia, meningitis, and urinary tract infections.
Transverse section of dicot root
Transverse section of dicot root
Transverse section of monocot root
