Animal and Plant Reproduction

Animal & Plant Reproduction

• Sexual reproduction requires 2 parents and produces a hybrid with gametes.
• Asexual reproduction requires 1 parent and produces a clone without gametes.

Animal Reproduction

• Animals have one type of generation with a full set of chromosomes (2n).
• Gametogenesis is the creation of sex cells.
• Fertilization is the union of sperm and egg to form a zygote.
• Cleavage is multiple rounds of mitosis, resulting in a blastula.
• Gastrulation forms germ layers for bodily tissues and organs.
• Organogenesis is the development of organs.
• Maturity is the stage where the organism can repeat the reproductive cycle.

Plant Reproduction

• Plants can alternate generations, using haploid (1n) and diploid (2n) cells.

Plant Gametogenesis and Fertilization

• Gametogenesis is the creation of sex cells, specifically sperm and ovule.
• Pollination transports sex cells via wind or animals.
• Double fertilization involves two sperm and one egg.
• One sperm fuses with the egg to form the zygote.
• The other sperm forms the endosperm, which provides nutrients to the zygote.
• Embryogenesis involves continued mitosis in the zygote, which is encased in a seed.
• The seed continues to grow into a plant.
• Plant ovaries develop into fruits, which contain seeds.

Animal & Plant Transport Systems

• Plants are autotrophs, producing their own food through photosynthesis.
• Animals are heterotrophs, ingesting organic molecules for sustenance.

Gas Exchange in Animals

• Single-celled organisms exchange gases through the cell membrane via diffusion.
• Amphibians breathe through their skin/epidermis, also releasing CO2, known as cutaneous respiration.
• Fish use countercurrent respiration to breathe through gills.
• Blood flow is counter to the water current.
• Insects take in oxygen through the trachea and release CO2.
• Oxygen is transported through some liquid.
• Humans take in oxygen through the pharynx and release CO2 through the larynx.
• Transportation occurs alveoli/air sacs and capillaries.

Gas Exchange in Plants

• Plants take in carbon dioxide for photosynthesis through stomata.
• Stomata close at night to prevent water loss through transpiration.
• Lenticels are holes that facilitate gas exchange.

Fluid Regulation in Humans

• Circulation involves the heart pumping blood through blood vessels, carrying red and white blood cells, platelets, plasma, nutrients, and oxygen.

Fluid Regulation in Plants

• Xylem transports water and minerals.
• Phloem transports food in the form of glucose.

Animal vs Plant - Nervous System

• Senses process information through:
• Presence of a physical stimulus
• Transmission of action potentials in sensory neurons
• Interpretation of the stimulus by the CNS
• Transduction of the stimulus into impulses in sensory receptors

Animal Nervous System

• Nerve cells are the basic unit,.
• Electrical impulses move away from the cell body (soma) towards the axon.
• The axon communicates with the body/other nerves and has branches that sense stimuli.
• Sensory neurons go to the brain.
• Motor neurons go out of the brain.
• Interneurons link sensory and motor neurons.

Central Nervous System

• The brain processes information from sense organs, controls emotions, intelligence, and homeostasis.
• The spinal cord sends information to and from the brain and nerves.

Peripheral Nervous System

• This system includes nerves in the limbs and body.
• The Somatic Nervous System has nerve endings connected to muscles for deliberate movement.
• The Autonomic Nervous System controls involuntary movement connected to organs.
• The Sympathetic Nervous System controls the "fight or flight" response.
• The Parasympathetic Nervous System controls "rest and digest" functions.
• Animals lacking a defined body/head have nerve nets throughout their body (e.g., Cnidarians).

Plants - Response and Survival

• Plants respond to stimuli by growing toward or away from them.
• Plants survive harsh conditions by changing their shape.

Plant Tropisms

• Plant tropisms indicate direction where Positive = Towards and Negative = Away and are non-reversible.
• Phototropism: response to sun/photons
• Hydrotropism: response to water
• Geotropism: response to gravity
• Thigmotropism: response to touch

Nastic Movements

• Nastic movements are reversible processes that are non-directional.
• They may or may not be growth-dependent.
• Thigmonasty: response to touch
• Seismonasty: response to movement
• Nyctinasty: response to time/night or day
• Thermonasty: response to temperature

Homeostasis

• A self-regulating process maintains internal stability while adjusting to external conditions.
• The body regulates constantly.
• Positive feedback amplifies and enhances to support a system.
• Negative feedback makes a change and controls.

Positive vs. Negative Feedback

• Positive feedback is rare compared to negative feedback.
• Childbirth: The fetus's head pushes on the cervix, stimulating a nerve impulse to the brain.
• Blood clotting: Substances are released to initiate clotting, accelerated by platelets.

Feedback Loops

• Receptors are the sensors that detect changes in the body.
• The Control Center monitors the body and signals effectors if something is wrong; often the hypothalamus, specifically the Medulla Oblongata.
• Effectors carry out the necessary actions.
• Communication is usually through hormones or nerves, where actions are translated.

Feedback Loops - Function, Receptors, Effectors, and Methods of Communication

• Regulation of body temperature adjusts to hot or cold situations through skin thermoreceptors, vasodilation/diaphoresis (for heat), or vasoconstriction/shivering (for cold).
• Regulation of body fluids is self-explanatory, using osmoreceptors, baroreceptors, and the RAAS system to control the kidney, adrenal glands, and brain via ADH/hormones.
• Regulation of gas concentration occurs when the body needs more oxygen
• Chemoreceptors (peripheral & chemoreceptors), inspiratory & expiratory respiratory muscles cause signals to be sent to the brain, prompting a process.
• Glucose regulation occurs when blood sugar increases or decreases from the normal using GPCRs, Glucagon Receptor, GLP-1 receptor which affects the pancreas and liver by regulating glucose levels.
• Blood pressure flows too fast or too slow in response to Baroreceptors (high & low pressure, Cardiopulmonary receptor) affecting the Sympathetic Nervous System & RAAS System causing baroreceptors to sense a change and send signals to the brain to cue effectors to initiate regulation.

Renin-Angiotensin-Aldosterone System (RAAS)

• Renin comes from the kidney.
• Angiotensin comes from the liver and is translated into angiotensin I and II by renin and lungs.
• Aldosterone comes from the adrenal gland.

Temperature Regulation

• It's negative feedback.
• The hypothalamus uses nerve cells to detect if hot/cold.
• HOT Vasodilation increases blood cell size and lowers blood pressure.
• HOT Diaphoresis(sweating) causes cooling via evaporation.
• COLD Vasoconstriction decreases blood cell size increasing blood pressure.
• COLD Shivering involves muscle movement that heats up and regulates temperature.

Bodily Fluids Regulation

• Decreased blood volumes and water level are detected by osmoreceptors and baroreceptors, which increases thirst.
• The brain releases ADH (antidiuretic hormone).
• The pituitary keeps ADH. Hypothalamus produces it.
• ADH controls renin release and tells the kidneys to absorb water and produce concentrated urine.
• The brain signals to drink water.

Gas Concentration Regulation

• Peripheral and central chemoreceptors in the brain sense high CO2 concentration.
• The brain adjusts respiratory or breathing rate.
• The Medulla Oblongota tells respiratory muscles to move
• Inspiratory muscles(diaphragm, etc) expand to breathe in. Expiratory muscles compress, while exhaling

Glucose Regulation

• Increased blood glucose causes increased osmolarity.
• When insulin is irregular, cells may struggle with glucose intake.
• Excessive insulin causes cells to take in too much glucose(low blood sugar).
• Brain stimulates the pancreas to produce glucagon
• glucagon tells the liver to breakdown stored glycogen back into glucose, and release it into the bloodstream.
• Insufficient insulin blocks glucose intake, increasing blood sugar.
• The brain tells the pancreas to release more insulin

Blood Pressure Regulation

• Baroreceptors in blood vessels detect irregular blood pressure, signaling the hypothalamus.
• Low blood pressure:
• Heart rate increases and pumps more blood.
• Kidneys release renin, producing angiotensin II, a vasoconstrictor that narrows blood vessels and raises pressure.
• High blood pressure:
• The heart rate decreases
• Vasodilation occurs.

Explore the fascinating world of animal and plant reproduction. Learn about the differences between sexual and asexual reproduction, gametogenesis, fertilization, and the development stages in animals. Discover plant reproduction through gametogenesis, pollination, and double fertilization.