Asexual vs Sexual Reproduction

• Asexual Reproduction is a mode of reproduction that does not involve gametes or sex cells
• Sexual Reproduction includes the use of gametes or sex cells
• Gametes are an organism's reproductive or sex cells, with the female having egg cells and the male having sperm cells
• Offspring are reproductive processes of an animal or plant
• Nutrients are substances for the growth and maintenance of an organism
• Autotrophs are organisms that get energy from sunlight and chemicals to produce their own food
• Heterotrophs cannot make their own food and obtain energy from other organisms

Plant Asexual Reproduction via Vegetative Propagation

• Plants can reproduce asexually through vegetative propagation
• Runners or Stolons refers to long, slender stems that grow along the surface of the soil, such as gabi, strawberries, and water lilies
• Suckers are roots that can give rise to new plants, like bamboos, bananas, and cherries
• Rhizomes are underground stems that grow horizontally and produce new plants at nodes, such as grasses, ginger, and sedges
• Corms, Bulbs, and Tubers are modified stems that store food reserves and produce new plants from buds within the structure, like potatoes, yams, onions, and tulips
• Sporulation is the production of specialized asexual reproductive cells called spores, exemplified by ferns
• Tissue Culture (Protoplast Fusion) is growing plant cells in a laboratory setting
• Protoplast fusion merges two plant cells' protoplasts to create a hybrid plant

Animal Asexual Reproduction

• Binary Fission splits a parent organism into two daughter organisms and is common in prokaryotic organisms and some invertebrates, such as cyanobacteria
• Budding reproduces an organism by forming an outgrowth, or a bud, from the parent organism's body as seen in Hydra
• Fragmentation reproduces an organism from a detached body part of its parent, exemplified by some species of sea stars
• Parthenogenesis develops an embryo from an unfertilized egg, as seen in some insects, reptiles, and fish

Sexual Reproduction in Animals

• External fertilization is common among aquatic organisms
• Internal fertilization is more common on land in vertebrates
• External Fertilization involves eggs and sperm meeting outside the female's body and occurs in fishes
• Internal Fertilization involves eggs being fertilized inside the female's body and embryonic development can occur through oviparity, ovoviviparity, and viviparity
• Oviparity means eggs are fertilized internally and deposited outside the mother's body to complete development, like with birds and reptiles
• Ovoviviparity means eggs are retained inside the mother to complete their development, with the embryo getting nourishment from the yolk, such as in some species of snakes and sharks
• Viviparity means the young develop inside the mother through the umbilical cord and not from the yolk, which is common in almost all mammals

Stages of Mammalian Animal Development

• Fertilization refers to the fusion of the egg and sperm that results in the formation of a zygote
• Cleavage occurs when the zygote undergoes rapid cell division, forming a ball of cells called a blastula
• Gastrulation occurs when the blastula undergoes cell movements, forming three germ layers: ectoderm, mesoderm, and endoderm
• The three germ layers give rise to all the tissues and organs of the developing organism
• Organogenesis is when cells from the three primary layers interact to form specific tissues and organs

Pollination

• Self-Pollination occurs when pollen is transferred between the anther and stigma of the same flower
• Cross-Pollination occurs when pollen is transferred between the anther and stigma of different flowers of the same plant or different plants of the same species

Gas Exchange

• Gas exchange occurs in the lungs
• Oxygen is absorbed into the bloodstream and carbon dioxide is removed
• Breathing is an involuntary process that occurs simultaneously with blood circulation
• The Respiratory system is the network of organs and tissues that help with breathing
• External respiration is the exchange of gases between the atmosphere and the lungs
• Internal respiration is the exchange of gases between cells and blood
• Blood Vessels are channels through which blood is distributed to body tissues
• Capillaries are tiny blood-containing structures that connect arterioles to venules, and are also the smallest and most abundant form of a blood vessel in the body
• Lungs are a pair of spongy, air-filled organs located on either side of the chest
• The Heart pumps blood through the network of arteries and veins
• Arteries are thick-walled vessels that allow the passage of oxygenated blood with the exception of the pulmonary artery
• The Aorta carries oxygenated blood from the heart to the rest of the body
• Veins are thin-walled vessels compared to arteries, carry non-oxygenated blood towards the heart with the exception of the pulmonary vein
• Blood carries nutrients and oxygen to the cells of the body and carries away carbon dioxide and nitrogenous waste from the body cells
• Valves prevent the backward flow of blood
• The Pulmonary Valve is located between the right ventricle and the pulmonary artery
• The Tricuspid Valve is located between the right atrium and the right ventricle
• The Mitral Valve is located between the left atrium and the left ventricle
• The Aortic Valve is located between the left ventricle and the aorta

Heart Chambers

• Chambers works together in a continuous and coordinated effort to keep oxygen-rich blood circulating
• The Right Atrium receives blood from the veins and pumps it to the right ventricle
• The Right Ventricle receives blood from the right atrium and pumps it to the lungs
• The Left Atrium receives oxygenated blood from the lungs and pumps it to the left ventricle
• The Left Ventricle is the strongest chamber and pumps oxygen-rich blood to the rest of the body, it's vigorous contractions create our blood pressure
• Systole occurs when the heart contracts to pump blood out
• Diastole occurs when the heart relaxes after contraction
• Xylem transports water from roots to stems and leaves, and also transports nutrients and water from roots
• Phloem transports the soluble organic compounds made during photosynthesis and transports food from leaves
• Turgor pressure forces within the cell that pushes the plasma membrane against the cell wall

Human Respiratory System

• Air enters through the nostrils, leading to the nasal passages in the Nose
• Air is cleaned, moistened, and warmed
• Hairs filter dust, and mucus traps bacteria, while cilia sweep the mucus and trapped particles out
• The Pharynx (Throat) is the passageway for both food and air
• The epiglottis closes off the airway during swallowing, and opens during breathing
• The Larynx (Voice Box) is located at the top of the trachea and contains the vocal cords
• The Trachea (Windpipe) is a tube that carries air to the lungs
• It is lined with mucus and cilia
• The Bronchi splits the trachea into two branches, each leading to a lung
• Lungs are spongy organs filled with tubes that branch into smaller and smaller tubes
• Bronchioles end in tiny air sacs called Alveoli, surrounded by blood vessels for the exchange of gases

Human Urinary System

• Kidneys filter blood, reabsorb essential substances, and produce urine and contain nephrons
• Nephrons are the functional units of the kidney
• The Renal Corpuscle filters blood and produces protein-free filtrate, including the Glomerulus and Bowman's Capsule
• The Glomerulus is a capillary network where filtration occurs
• Bowman's Capsule surrounds the glomerulus and collects the filtrate
• The Tubules are part of the Nephron, including the Proximal Convoluted Tubule, Loop of Henle, Distal Convoluted Tubule, and Collecting Tubules
• The Proximal Convoluted Tubule reabsorbs most water, nutrients, and ions
• The Loop of Henle concentrates the filtrate by reabsorbing water
• The Distal Convoluted Tubule regulates ion balance and is influenced by hormones
• The Collecting Tubules regulate water reabsorption
• Antidiuretic hormone (ADH) helps the kidneys manage the amount of water
• Ureters transport urine from the kidneys to the bladder
• The Bladder stores urine
• The Urethra carries urine from the bladder to the outside of the body
• Urination occurs when urine is released from the bladder through the urethra
• The external sphincter relaxes voluntarily, while the internal sphincter is controlled by the autonomic nervous system

Urethra Differences

• Males: Longer, extending from the bladder to the tip of the penis, carrying both urine and semen
• Females: Shorter, located behind the symphysis pubis, carrying only urine

Types of Immunity

• Inborn immunity is a genetic predisposition where immunity comes from ancestors
• Acquired immunity with a natural or artificial source progresses the moment a person is born
• Naturally acquired immunity occurs when a person is exposed to a live pathogen, develops the disease, and becomes immune
• Artificially acquired immunity is introduced through a vaccine
• Antibodies or immunoglobulins recognizes and bind to an antigen which then could result in their destruction

Nervous System

• The Nervous System controls all the activities of the body and is made of billions of nerve cells called Neurons
• Neurons transmits impulses to the different parts of the body
• The Central Nervous System (CNS) consists of the brain and the spinal cord
• The Peripheral Nervous System (PNS) consists of nerves and receptors
• Unipolar Neurons are sensory neurons
• Multipolar Neurons (Motor Neuron) are connected to muscles
• Bipolar Neurons (Interneurons) are interneurons that bridge and process messages from sensory neurons to motor neurons

Human Brain and Central Nervous System

• The Cerebrum is the largest part of the brain and has numerous folds or wrinkles
• It is the center of sensory, perception, memory, thought, and personality, and is divided into two symmetrical hemispheres
• The Right Cerebral Hemisphere controls the left side of the body
• The Left Cerebral Hemisphere controls the right side of the body
• The Cerebellum, also called the hindbrain, controls motor functions
• The Brain Stem joins the brain and the spinal cord, and includes the midbrain, the pons, and the medulla oblongata
• The Midbrain is associated with vision, hearing, alertness, sleep wake patterns, and temperature regulations
• The Pons relays signals to the thalamus, and it is associated with sleeping and dreaming
• The Medulla Oblongata is responsible for involuntary movements
• The Spinal Cord extends from the medulla oblongata and sends signals from the brain to the rest of the body

Peripheral Nervous System (PNS)

• This consists of nerves arising from the brain and the spinal cord
• There are afferent sensory pathways, and the efferent motor pathways that act on the stimuli
• Sensory organs and their functions:
• Eyes: detect light
• Ears: detect sound and maintain balance
• Nose: detect odors
• Tongue: detect taste
• Skin: detect touch, pain, temperature and pressure

Sensory Receptors

• Photoreceptors: detect light (eyes)
• Mechanoreceptors: detect pressure, vibration, and stretch (skin, ears)
• Chemoreceptors: detect chemicals (nose, tongue)
• Thermoreceptors: detect temperature (skin)
• Nociceptors: detect pain (skin)

Plant Response

• Tropism is a biological mechanism that enables the plant to move toward (positive tropism) or against (negative tropism) the source of a stimulus Geotropism/gravitropism: growth in response to gravity Hydrotropism: growth towards water

Plant Hormones

• Auxins influence cell division, cell elongation, cell differentiation affecting apical dominance, tropisms, flowering, abscission and senescence
• Gibberellins increase elongation growth
• Ethylene promotes ripening of fruits and abscission
• Cytokinins regulate cell division
• Abscisic Acid inhibits other hormones, promoting dormancy in plants and seeds

Feedback Mechanism

• Ectotherms are animals that do not have internal control of their body and absorbs heat from the surroundings
• Endotherms maintain a constant body temperature
• Thermoregulation maintains a steady internal body temperature despite changes in external conditions
• Osmoregulation maintains salt and water balance across membranes within the body

Homeostasis

• Homeostasis resists change and maintains a stable internal environment
• Negative Feedback reduces an excessive response and keeps a variable within the normal range like Body temperature regulation and control of blood glucose
• Positive Feedback intensifies a response until an endpoint is reached: Blood clotting and childbirth
• Blood Glucose Regulation maintains blood glucose levels
• Blood Clotting responds to a wound by clotting the blood and stopping blood loss