Bio Life G Explained

The nephron is the structural and functional unit of the kidney. It filters blood, forms urine, and maintains water and salt balance. Alveoli are in the lungs, villi are in the small intestine, and neither is part of the kidney.

Nephrons filter metabolic waste products like urea, excess salts, and water from the blood to form urine. The heart pumps blood, the digestive system digests food, and red blood cells transport oxygen.

In the kidneys, blood pressure forces water, urea, and small solutes out of the glomerular capillaries and into Bowman’s capsule. This process is called filtration. Respiration is gas exchange, absorption occurs in the intestine, and circulation is blood flow.

The kidneys adjust urine output based on the body’s water balance and hydration level. If you drink more water, urine output increases; if you are dehydrated, urine becomes concentrated and volume decreases. Blood group, weather alone, or age alone are not the primary factors.

The kidneys regulate water balance by excreting excess water as urine. The lungs remove carbon dioxide, the heart pumps blood, and the liver detoxifies chemicals but does not remove excess water.

Excretion is the biological process of removing metabolic waste products such as urea, carbon dioxide, and excess salts from the body. Respiration releases energy, nutrition is food intake, and transport moves substances.

The kidneys are the primary excretory organs for nitrogenous wastes like urea and uric acid. The lungs excrete only carbon dioxide, while veins and arteries are blood vessels that transport blood, not excrete wastes.

Plant cells have large central vacuoles that store harmful metabolic wastes such as tannins, alkaloids, and calcium oxalate crystals. The nucleus controls cell activities, the cell wall provides support, and the cytoplasm is for cellular processes.

Gums and resins are waste products that accumulate in old or dead xylem vessels and ducts in plants. Roots absorb water, leaves are for photosynthesis, and phloem transports food.

Many plants store waste products in old leaves. When these leaves fall off, the wastes are removed from the plant body. Dialysis and sweating occur in animals, and blinking is a reflex action of eyes.

Movement in living organisms includes not just visible locomotion but also internal movements such as blood circulation, cytoplasmic streaming, and peristalsis. Growth alone or visible motion alone does not fully define movement.

Respiration, excretion, and circulation are universal life processes found in almost all living organisms. Germination is a specific process that occurs only in plants during seed growth, not in animals or other living beings.

Life processes such as nutrition, respiration, transportation, and excretion are essential for maintaining life. Without these, an organism cannot survive. Growth and repair are outcomes of survival, not the primary necessity.

Nutrition is the process that includes the intake (ingestion) of food, its digestion, absorption, and utilization by the body. Respiration is energy release, circulation is transport, and excretion is waste removal.

Respiration is a biochemical process that breaks down glucose inside cells to release energy in the form of ATP. Breathing is only the physical exchange of gases, not the entire process of respiration.

ATP (adenosine triphosphate) is the energy currency of the cell. The energy released from the breakdown of glucose is captured and stored in the high-energy phosphate bonds of ATP. DNA and RNA are genetic materials, and enzymes are proteins that speed up reactions.

ATP is synthesized during cellular respiration when glucose is oxidized. Digestion breaks down food but does not produce ATP directly. Growth uses ATP, and destruction is not a process that produces ATP.

ATP powers every cellular function including muscle contraction, protein synthesis, nerve impulse conduction, cell division, active transport, and many others. It is not limited to muscles, digestion, or breathing alone.

Respiration can occur in the presence of oxygen (aerobic respiration) or in the absence of oxygen (anaerobic respiration). Aerobic produces more ATP, while anaerobic produces less ATP and occurs in organisms like yeast or in human muscles during intense exercise.

Aerobic respiration completely oxidizes glucose into carbon dioxide and water, producing about 36-38 ATP molecules per glucose. This is much more energy than anaerobic respiration, which produces only 2 ATP per glucose.

Anaerobic respiration takes place in the absence of oxygen. It occurs in some bacteria, yeast (fermentation), and in human muscle cells during strenuous exercise when oxygen supply is insufficient.

Autotrophs like green plants use sunlight as the energy source to convert carbon dioxide and water into glucose through photosynthesis. They do not use animals, oxygen alone, or protein to make their food.

Autotrophic nutrition uses simple inorganic substances like carbon dioxide, water, and minerals to synthesize organic food. Meat, blood, and milk are organic materials used by heterotrophs, not autotrophs.

Green plants contain chlorophyll and can produce their own food through photosynthesis, making them autotrophs. Heterotrophs, saprophytes, and parasites depend on other organisms for food.

Heterotrophs cannot synthesize their own food, so they directly or indirectly depend on autotrophs (plants) for organic nutrients. Water, soil, and oxygen are needed but are not the source of food.

Both animals and fungi are heterotrophs because they obtain ready-made organic food from other sources. Animals ingest food, while fungi absorb nutrients from decaying matter. They are not autotrophs or producers.

The inner lining of the small intestine has millions of finger-like projections called villi that absorb digested nutrients like glucose, amino acids, and fatty acids into the blood. The stomach digests food, the colon absorbs water, and the liver processes nutrients.

After absorption in the small intestine, nutrients enter the bloodstream. The blood then transports these nutrients to all cells of the body. Nerves carry impulses, lymph helps but is not the main transporter, and air does not carry nutrients.

The transport system (circulatory system) in humans consists of the heart (pump), blood (fluid), and blood vessels (tubes). The brain controls the body, lungs exchange gases, and kidneys excrete wastes.

The heart is the central organ of the circulatory system. It continuously contracts and relaxes to pump blood throughout the body. The brain controls functions, the liver processes nutrients, and the kidneys filter blood.

Blood transports digested food (nutrients) from the small intestine, oxygen from the lungs to tissues, carbon dioxide and urea (wastes) from tissues to excretory organs, and hormones. It carries all these substances simultaneously.

Vascular tissue in plants is composed of xylem (transports water and minerals) and phloem (transports food). Cortex, pith, cambium, and epidermis are other plant tissues but not vascular tissues.

Xylem is a plant tissue that transports water and dissolved minerals absorbed by roots upward to the leaves and other parts. Food and sugars are transported by phloem, not xylem.

Phloem transports the products of photosynthesis, mainly sucrose (sugar), from leaves (source) to other parts like roots, fruits, and growing buds (sink). Water and minerals move through xylem.

Plants have a much lower metabolic rate and energy demand compared to animals. They do not need rapid transport because they are not highly active. Xylem transport is passive (driven by transpiration pull), and phloem transport is slower than animal circulation.

Nephrons filter nitrogenous wastes like urea and uric acid from the blood. Carbon dioxide is removed by the lungs, oxygen is carried to tissues, and glucose is normally reabsorbed back into blood, not removed.

Urea is a nitrogenous waste produced in the liver from protein breakdown. The kidneys filter urea from the blood and excrete it in urine. The lungs remove carbon dioxide, the heart pumps blood, and the stomach digests food.

Plants do not have specialized excretory organs. They store waste products like tannins, resins, and calcium oxalate in vacuoles, old leaves, bark, or xylem. Urine, dialysis, and sweating are animal or artificial processes.

When plants store wastes in old leaves, those leaves eventually fall off, effectively removing the wastes from the plant body. Digestion, circulation, and respiration are not methods of waste removal in plants.

During photosynthesis, plants split water molecules and release oxygen as a byproduct or waste product. Respiration consumes oxygen, while digestion and circulation do not produce oxygen as a waste.

All living organisms exhibit some form of movement, whether visible (walking, flying) or internal (blood flow, cytoplasmic streaming). Movement requires energy (ATP) and is a defining characteristic of life. Dead organisms do not show movement.

Life processes such as nutrition, respiration, and excretion work together to maintain homeostasis, which is the stable internal order of the body. They do not maintain clothes, hair growth alone, or the external environment.

Digestive enzymes break down large, complex macromolecules (starch, proteins, fats) into simple, soluble molecules (glucose, amino acids, fatty acids and glycerol) that can be absorbed into the blood. Digestion does not produce larger units or only water.

Glucose is broken down during cellular respiration to release energy, which is stored as ATP. Nutrition is the intake of food, transport moves substances, and growth uses energy but does not release it from glucose.

ATP is the correct abbreviation for adenosine triphosphate, the energy currency of the cell. It consists of adenosine (adenine + ribose) attached to three phosphate groups. The other options are incorrect expansions.

Aerobic respiration uses oxygen to completely break down glucose into carbon dioxide and water, producing about 36-38 ATP molecules. Anaerobic respiration produces only 2 ATP. Digestion and transport do not release significant energy.

The kidney’s primary function is to filter nitrogenous waste, mainly urea, from the blood. Sugar and protein are normally reabsorbed and not excreted in urine. Oxygen is carried by blood, not removed by kidneys.

Plant cells have large central vacuoles that store waste products such as tannins, alkaloids, and calcium oxalate crystals. Animal cells have small temporary vacuoles but not for long-term waste storage. Bacteria and viruses lack such vacuoles.

In humans, excess nitrogen from protein breakdown is converted into urea in the liver and excreted in urine. CO₂ is carbon waste, oxygen is a gas, and starch is a carbohydrate storage molecule, not a nitrogen waste.

Life processes such as nutrition, respiration, circulation, and excretion work together to maintain the body’s internal environment, repair damage, provide energy, and ensure survival. They are not for decoration, movement alone, or sleeping.