Cell Cycle: Mitosis, Interphase & Cytokinesis

• Study notes based on the provided text

Cell Cycle Stages

• Interphase includes G1, S, and G2 phases
• During the G1 phase, the cell grows and conducts normal functions
• DNA replication occurs in the S phase, preparing the cell for division
• The cell continues to grow and prepares for mitosis during the G2 phase

Mitosis

• Prophase involves: chromosome condensation, nuclear membrane dissolving, and spindle fibers forming
• During metaphase chromosomes align at the cell's center, also known as the equator
• Anaphase involves pulling sister chromatids apart to opposite sides of the cell
• Telophase involves the formation of new nuclear membranes around each set of chromosomes

Cytokinesis

• Involves the division of the cytoplasm and other cell contents, resulting in two daughter cells

Cell Specialization

• Specialization is when a cell develops specific structures and functions to perform a particular task
• Muscle cells contain numerous mitochondria for energy and are elongated for contraction
• Red blood cells lack a nucleus and contain hemoglobin for oxygen transport
• Nerve cells (neurons) are long and branched to transmit electrical signals

Apoptosis (Programmed Cell Death)

• Apoptosis is a controlled process where cells self-destruct preventing cancer or infection
• The cell receives signals that activate enzymes to break down its components
• The cell shrinks and is phagocytosed by neighboring cells without releasing harmful contents

Parts of Nephron and Function

• The renal corpuscle includes the glomerulus (a network of capillaries) that filters blood
• The renal corpuscle produces filtrate, which is a precursor to urine
• The proximal convoluted tubule reabsorbs water, glucose, and ions back into the blood
• The Loop of Henle creates a concentration gradient in the kidney for water reabsorption
• The distal convoluted tubule regulates electrolyte balance by selectively absorbing or secreting ions
• The collecting duct is the final part of the nephron which adjusts urine concentration and pH

Liver Function and Intestines

• The liver detoxifies harmful substances, metabolizes drugs, and produces bile for fat digestion
• The liver stores glycogen (energy) and converts excess glucose into fat
• The liver regulates blood clotting by producing clotting factors
• The small intestine is the main site for nutrient digestion and absorption
• The large intestine absorbs water and salts, forms, and stores feces

Xylem and Phloem

• Xylem transports water and minerals from roots to leaves through capillary action
• Xylem is made up of dead cells that form tubes (vessels) for water movement
• Phloem transports nutrients (mainly sugars) from leaves to other parts of the plant
• Phloem is made of living cells (sieve tubes) with perforated ends that allow sugar flow

Digestion Processes: Physical and Chemical

• Physical digestion is the mechanical breakdown of food into smaller pieces (e.g., chewing, stomach churning)
• Physical digestion increases surface area for enzyme action
• Chemical digestion breaks down large food molecules (proteins, carbs, fats) into smaller molecules (amino acids, glucose, fatty acids) via enzymes
• Chemical digestion mainly occurs in the stomach and small intestine

Enzymes for Digestion

• Amylase breaks down starch into maltose and is found in the mouth and small intestine
• Protease (e.g., pepsin) breaks down proteins into amino acids and is found in the stomach and small intestine
• Lipase breaks down fats into fatty acids and glycerol and is found in the small intestine

Malfunction in Cells Leading to Cancer

• Mutations in genes that regulate the cell cycle (oncogenes or tumor suppressor genes) can lead to cancer
• Uncontrolled cell division causes mutated cells to divide excessively, forming tumors

Sections of Blastocyst Relating to Stem Cells

• The inner cell mass forms the embryo and contains pluripotent stem cells, which can differentiate into any cell type in the body
• The trophoblast forms the placenta and helps in implantation in the uterus

Intrinsic and Extrinsic Pathways (Apoptosis)

• The intrinsic pathway is triggered by internal cellular damage, leading to mitochondrial release of pro-apoptotic proteins
• The extrinsic pathway is triggered by external signals, such as death ligands binding to cell surface receptors (e.g., TNF receptors)

Root and Shoot Systems

• The root system anchors the plant in soil and absorbs water and minerals
• The root system includes primary roots (taproot) and secondary roots (lateral roots)
• The shoot system supports leaves, flowers, and stems, involved in photosynthesis and reproduction

Excretory and Digestive System

• The excretory system removes metabolic wastes from the body via the kidneys and bladder
• The kidneys filter blood and regulate water and electrolyte balance
• The digestive system breaks down food into nutrients that can be absorbed and used by the body via the mouth, stomach, and intestines

Kidneys Relating to Size of Molecules

• Kidneys filter molecules based on size
• Small molecules (water, ions, glucose) pass through the glomerulus into the nephron
• Large molecules (proteins, blood cells) are retained in the bloodstream

Prokaryotic Binary Fission

• Binary fission is a form of asexual reproduction in prokaryotic cells (e.g., bacteria)
• During binary fission the cell replicates its DNA and divides into two genetically identical daughter cells

Peristalsis

• Peristalsis is the wave-like muscular contractions that push food through the digestive system (esophagus, intestines)
• Peristalsis involves smooth muscle contractions and relaxations

Plant Phyla

• Plant phyla are a classification of plants based on characteristics
• Bryophytes (mosses) are non-vascular and live in moist environments
• Pteridophytes (ferns) are vascular and reproduce via spores
• Gymnosperms (conifers) are vascular and produce seeds but not flowers
• Angiosperms (flowering plants) are vascular and produce seeds within flowers

Tissue Types in Plants and Animals

• Plant tissues include: meristematic, dermal, vascular, and ground
• Meristematic tissues are for growth and cell division (apical and lateral meristems)
• Dermal tissue is a protective outer layer (epidermis)
• Vascular tissues is for transport (xylem and phloem)
• Ground tissue is for photosynthesis, storage, and support
• Animal tissues include: epithelial, connective, muscle, and nervous
• Epithelial tissue covers body surfaces and organs
• Connective tissue provides structural support in the form of bone or blood
• Muscle tissue facilitates movement and can be skeletal, cardiac or smooth
• Nervous tissue transmits signals with neurons

Transpiration

• Transpiration involves water absorption by roots, movement through the plant, and evaporation from the leaves
• Transpiration is regulated by stomata and helps cool the plant

Adhesion and Cohesion

• Adhesion involves water molecules sticking to other substances, this is important in water movement through xylem
• Cohesion involves water molecules sticking to each other, and is important for forming water columns in xylem

Guard Cells

• Guard cells are found around stomata and regulate gas exchange and water loss by opening and closing the stomata
• Guard cells open during the day for photosynthesis and close at night to conserve water

Translocation

• Translocation involves the movement of nutrients and sugars through the phloem from source (leaves) to sink (roots, fruits, etc.)

Factors Affecting All of the Above

• Temperature affects enzyme activity, transpiration rate, and metabolic processes
• Water availability impacts plant growth, transpiration, and digestion
• Light influences photosynthesis and transpiration
• Concentration gradients drive diffusion and osmosis
• Genetic factors affect cell differentiation, function, and response to environmental stimuli