Biology: Plant and Animal Reproduction

• General Biology 2 covers heredity, variation, diversity of living organisms, structure, function, and evolution.
• There are list of activities to be completed with Raw scores totaling 290
• The grading system is based on 50% performance check , 30% enabling assessment activity and 20% quarterly examination.

Reproduction and Development in Plants and Animals

• Reproduction is a biological process where organisms produce offspring, improving species, and enhancing survival traits.
• Reproduction in plants and animals can be either asexual or sexual.

Plant Reproduction

• Asexual reproduction involves one parent with no sex cells; classification bases on organ involvement.
• In vegetative reproduction, a plant part reproduces another, producing adventitious shoots and roots.
• Humans also came up with artificial propagation like cutting, grafting, layering, and tissue culture.
• Sexual reproduction involves sperm and egg cells combining, inside or outside the body.
• All plants exhibit a diplohaplontic reproductive life cycle with alternating sporophyte (spore production) and gametophyte generations (which produces gemetes).
• In this life cycle, spores, produced by meiosis, are the first cell of the haploid gametophyte generation
• Gametes fuse during fertilization, forming a zygote that doubles the chromosome number, initiating the diploid sporophyte generation.
• Sporophyte and gametophyte generations can be heteromorphic (unalike) or isomorphic.
• In flowering plants, the flower is the site of spore formation, containing male and female gametophytes.
• Flowering plants undergo double fertilization where a pollen tube grows to the embryo sac.
• One sperm nucleus fuses with the egg nucleus (making a diploid zygote)
• The other sperm nucleus fuses with the diploid fusion nucleus (making a triploid endosperm nucleus); and the tube nucleus, synergids and antipodals all degenerate.
• Flower structures include spore-forming carpels and stamens.
• Sterile structures (petals and sepals) aren't directly involved in spore production.

Reproductive Traits

• Plants and animals use color displays for reproduction, but fertilization in flowering plants relies on pollination through wind, water, or animals.
• Animal Reproduction

Asexual Reproduction

• Does not involve gametes, and is observed in lower animal forms.
• Types of asexual reproduction:
• Budding: An organism forms an outgrowth (bud) from its body.
• Fragmentation: Occurs when a new organism grows from a detached body part.
• Binary Fission: An organism splits into two daughters (prokaryotes/invertebrates)

Sexual Reproduction

• Exhibited by the diplontic life cycle of higher beings
• Haploid cells are gametes
• Sperm and egg fuse for generic diversity, creating a zygote, eventually becomes the embryo

Animal Gametogenesis

• Reproductive cells are produced in gonads (reproductive organs), called gametogenesis.
• Spermatozoa (male) created in the testes
• Ova (female) created in ovaries
• Spermatogenesis: genetic content halve and substances are prepared for fertilization.
• Oogenesis: halving genetic content and preparing yolk reserve in egg cytoplasm.
• Fertilization involves egg activation and fusion of egg and sperm nuclei (amphimixis).
• External fertilization sheds egg and sperm in the water, while internal fertilization puts sperm in the female tract.

Development

• Development involves sequential steps of transforming a zygote into a mature individual.
• Plants and animals evolved differently; molecularly dissimilar genes makeup their structure.
• Plant Development
• Plant development is rooted: cells are stationary during unicellular and growth stages
• Body plans are highly environmentally regulated.
• Plants exhibit alternation of generations and open development with meristematic tissues.
• Seed plant development divides into maturation, seed germination, and seedling maturity, with the zygote undergoing cell division to form the embryo.
• Flowering plants seed are contained within the fertilized ovule, where the it is associated with the development of the fruit.

Animal Development

• Animal development is programmed and unchangeable
• Three stages: pre-embryonic, embryonic, and post-embryonic.
• The egg develops into animal and vegetal hemispheres
• Fertilization via amphimixis, and sometimes parthenogenesis (development without sperm).
• Embryonic development features cell division and growth, morphogenesis, and differentiation.
• Post-embryonic: organs becoming fully functional.

Lesson 2: Nutrition, Gas Exchange, and Circulation in Plants and Animals

Nutrition

• Nutrition is the process of obtaining food for energy, survival, and growth.
• Autotrophic Organisms
• Synthesize inorganic materials
• photoautotrophs get energy from the sun
• chemoautotrophs use chemicals
• Heterotrophic Organisms
• cannot make food, they digest organic matter
• saprophytic obtain nutrients from dead organic matter
• parasitic take food from another organism (host inside/out)
• holozoic ingest solid/liquid food, types include; herbivorous (plants only), carnivorous (animals only), and omnivorous (both plants and animals)

Gas Exchange

• Gas exchange is a process to required for metabolic reactions to occur.
• It includes using oxygen releasing carbon dioxide.
• Gas Exchange in Animals
• Animals exchange carbon dioxide and oxygen in varying ways
• Examples include; their membranes, skin, gills, tracheal systems and lungs.

Gas Exchange in Plants

• In plants, gas exchange occurs mainly in the leaves
• Plants have different mechanisms to perform this process, with specialized pores called stomata with surrounding guard cells

Transport/Circulation

• Organisms transport molecules in bodies and remove waste via circulatory systems for breathing, nutrition, and sustaining internal environment.
• Plants circulate by :
• Xylem transports nutrients
• Pholem transports sugars
• Animals circulate blood with vessels and heart,

Lesson 3: Regulation of Fluids, Chemical and Nervous Control, Immune System, and Sensory and Motor Mechanism in Plants and Animals

Regulation of Fluids

• Plants and animals regulate fluids for bodily functions.
• In plants, water is vital for photosynthesis.
• Plants regulate water via osmosis (movement across membranes), transpiration (water evaporates through stomata)
• Water can move upward via adhesion to xylem, cohesion keeps all the water together (capillary action).
• Animals need fluids as well; the concentration is regulated based on the environment theyre in

Chemical and Nervous Control

• Higher animals have intricate nervrous control
• Nerve nets in animals and root/apex in plant counterpart
• Controls the activities through cell and muscles
• Plants dont have nervous control instead, their strands act like nerves that supply water
• Both use hormones which act like chemical control

Immune Systems

• Immune system protects organisms from diseases
• Animals can become immune
• Specialized cells (lymphocytes) destroy foreign bodies
• Plants lack immune/circulatory systems; cells independently respond to pathogens, triggering cell wall changes, antimicrobial compound production, and even cell death.

Sensory and Motor Mechanism

• Controlled by nervous systems in animals that can respond to stimuli; physical stimulus initiates sensation, transduction into electrochemical impulses, transmission via sensory neurons, and interpretation.
• Plants respond to stimuli liek light, chemicals (tropism) where tropism is the ability to be affected by particular stimulus

Lesson 4: Feedback Mechanism

Feedback Mechanism

• Feedback mechanisms happen when body systems are regulated to maintain balance.
• Homeostasis maintains internal environment, allowing the body to function well
• Homeostasis involves feedback mechanisms controlling temperature, fluids, gas, blood, and glucose.
• Semipermeable cell membranes use signal receptors to detect steady-state disruptions, signaling the nervous and endocrine systems.
• Processes include: stimulus-response, negative and positive feedback
• Maintaining constant internal temperature for metabolic processes
• Balanced levels carbon dioxide and oxygen needed inside the body