Biology Chapter on Development and Nutrition

Report Assignments

• Students will be exempted from the periodical exam if they get 25 points
• Students will be exempted from the summative exam if they get 24 points
• The time allotted per reporter is 10 minutes

Reproduction and Development

• Development is a series of changes in a multicellular organism from a single cell
• Animal development includes stages like zygote, eight cells, blastula, gastrula, larva, and adult
• Plant development includes stages like zygote cells, two 8 celled embryo, "globular" embryo, "heart" embryo, "torpedo" embryo and mature plant
• Four key processes underlie development: Determination, Differentiation, Morphogenesis, and Growth
  • Determination sets the fate of a cell(e.g., muscle, fat)
  • Differentiation creates specialized cells from unspecialized ones
  • Morphogenesis organizes and arranges cells to form tissues and organs
  • Growth increases size via cell division and expansion

Nutrition

• Nutrients are substances essential for growth and maintenance, categorized into:
  • Autotrophs make their own food (plants/chemosynthetic bacteria)
  • Heterotrophs consume other organisms for energy (animals/fungi)
• Plant nutrition requires: water, carbon dioxide, and essential nutrients (macronutrients above 0.5% and micronutrients in trace amounts).
• Macronutrients examples of C,H,O,N,K,Ca,Mg,P,S
• Micronutrients examples of CI,Fe,B,Mn,Zn,Co,Mo

Animal Nutrition

• A Calorie is a unit of energy measuring the heat required to raise 1kg of water by 1 degree Celsius
• Carbohydrates (4 Calories/gram) are a major energy source from grains, fruits, and vegetables.
• Proteins (4 Calories/gram) are building materials (muscles, tissues, enzymes) from dairy, poultry, fish, meat, and grains.
• Fats (9 Calories/gram) are building materials (cell membranes and hormones), energy storage from oils, margarine, butter, meats, and processed foods.
• Essential nutrients include essential amino acids (8 for humans) and essential fatty acids like linoleic acid.
• The main stages of food processing are: ingestion, digestion, absorption, and elimination

Animal and Plant Reproduction

• Reproduction, the process creating offspring of either plant or animal.
• Plant reproduction, development, nutrition, gas exchange, transport/circulation, regulation of body fluids, chemical and nervous control, sensory and motor mechanisms

Gas Exchange

• Crucial for survival, unicellular organisms use diffusion for gas exchange.
• Multicellular organisms use complex systems.
• In plants, stomata, leaves, and transpiration play key roles
• Stomata open and close to permit the flow of carbon dioxide and oxygen for photosynthesis and respiration (respectively)
• In animals, gases are exchanged with the external environment across moist membranes
• Terrestrial arthropods have spiracles and trachea
• Aquatic animals use gills.

Transport and Circulation

• Plants have xylem (water/solutes) and phloem (food) transport systems.
• Plants have adaptations to reduce excessive water loss (e.g., cuticle, needle-shaped leaves)
• Animals have open or closed circulatory systems
• Open systems (many invertebrates) circulate blood into body cavity
• Closed systems (vertebrates) use blood vessels for circulation (pulmonary and systemic)
• Pulmonary circulation transports blood to the lungs to unload carbon dioxide and load oxygen
• Systemic circulation carries oxygenated blood to the body tissues

Regulation of Body Fluids

• Osmosis is the movement of solvent molecules through a semipermeable membrane from an area of lower solute concentration to an area of higher solute concentration
• Osmoregulation is the regulation of water and electrolyte balance in organisms

Chemical and Nervous Control

• Animal behavior is controlled by the nervous system which has nerve cells called neurons
• Sensory receptors detect stimuli such as light, sound, temperature, touch, and chemicals; and convert it into electrical signals.
• Sensory transduction is the process of converting a stimulus into an electrical signal
• Different types of sensory receptors detect various stimuli: mechanoreceptors, thermoreceptors, chemoreceptors, photoreceptors, and pain receptors.

Sensory and Motor Mechanisms

• Sensory receptors are crucial for learning about the environments around or internal body state, and the conversion of stimuli into nervous signals
• Specialized cells: photoreceptors, mechanoreceptors, thermoreceptors, and chemoreceptors, are examples of structural receptor types and how they respond to stimuli such as pressure, light, heat, and chemicals. Interoceptors detect changes within the body, for example, blood pressure
• Proprioceptors monitor body position and movement.
• Sensation is the activation of sensory receptors, while perception is interpreting those signals
• Receptor types include photoreceptors (retina), mechanoreceptors (skin, ears), thermoreceptors (skin), chemoreceptors (tongue, nose), and pain receptors.

Immune System

• Immune systems are divided into innate (immediate) and adaptive (specific) responses
• Innate immunity includes physical barriers (skin), chemical responses, and cellular attacks
• Adaptive immunity is a slower but targeted response involving antigen-specific immune cells

Functional Receptor Types

• Chemical stimuli are detected by chemoreceptors
• Physical stimuli (pressure, vibration, sound, body position) are detected by mechanoreceptors
• Thermoreceptors detect temperature changes (heat and cold)

Plant Responses

• Plants respond to environmental stimuli like light, gravity, touch, and chemicals.
• Plant tropisms are directional growth responses (e.g., phototropism, geotropism)
• Plants also experience daily and seasonal responses (e.g., opening/closing of leaves, dormancy)
• Plants have responses to diseases.

Homeostasis and Temperature Control

• Homeostasis is dynamic equilibrium in the body. Systems are in balance as they constantly respond to changes in internal and external stimuli
• A negative feedback loop (e.g., regulation of blood temperature) causes a response in a direction opposite to the stimulus.
• A positive feedback loop (e.g., blood clotting) accelerates a response in the same direction as the stimulus.

Types of Eyes

• Flatworms have eye cups
• Insects have compound eyes
• Humans have single lens eyes

This quiz covers key concepts related to the development of multicellular organisms and the essentials of nutrition. It includes stages of animal and plant development as well as the four critical processes that underlie growth and differentiation. Test your knowledge on these foundational topics in biology.