Plant & Animal Organ Systems: Reproduction & Development

General Biology II: Plant and Animal Organ Systems and their Functions

• The study material examines reproduction, development, and nutrition in plants and animals.
• It compares these processes across both plant and animal kingdoms.

Plant Reproduction

• Flowering plant propagation via sexual and asexual reproduction is fundamental to agriculture.
• Plant life cycles feature alternating generations of haploid (n) and diploid (2n) stages.
• A diploid sporophyte plant creates haploid spores through meiosis.
• These spores undergo mitosis to produce haploid gametophytes.
• Gametophytes yield gametes, like sperm and eggs.
• Fertilization leads to diploid zygotes, which divide by mitosis, generating new sporophytes.

Flower Structure

• Angiosperm sporophytes' reproductive shoots, known as flowers, typically have four whorls of modified leaves termed floral organs.
• Floral organs are separated by short internodes.
• They are determinate shoots, ceasing growth after flower and fruit formation.

Floral Organs

• Flower parts, including sepals, petals, stamens, and carpels, attach to the receptacle.
• Sepals are green, leaf-like structures that protect the flower bud.
• Petals are colorful to attract pollinators.
• Stamens are the male parts, composed of a filament stalk and an anther, which produces pollen.
• Carpels or pistils are the female parts.
• The ovary contains ovules.
• The style is a long neck.
• The stigma serves as a sticky tip for pollen reception.
• The pistil can be a single carpel or multiple fused carpels.

Types of Flowers based on Whorl Presence:

• Complete flowers have sepals, petals, pistils, and stamens.
• Incomplete flowers miss at least one of these parts

Types of Flowers based on Reproductive Whorl Presence:

• Perfect or bisexual flowers possess both male and female reproductive structures on the same flower.
• Androecium is the whorl of stamens.
• Gynoecium is the whorl of carpels.
• Roses are an example.
• Imperfect or unisexual flowers lack either male or female structures.
• Staminate flowers are male.
• Carpellate/pistillate flowers are female.
• Examples include squashes, cucumbers, corn, and grasses.

Gametophyte Development and Pollination

• Sporangia within anthers and ovules are structures in which spores are created through meiosis.
• Pollen grains: Male gametophytes with a spore wall form in anther pollen sacs, or microsporangia.
• Embryo Sac is the female gametophyte formed inside the ovule.
• Pollination involves the transfer of pollen from the anther to the stigma.
• A pollen tube extends via the style to transport sperm to the embryo sac for fertilization.
• Fertilization occurs when sperm fertilizes the egg, generating a zygote that develops into an embryo.
• Seed Formation: An ovule develops into a seed.
• Fruit Development: The ovary becomes a fruit containing seeds.
• Seeds disperse via gravity, wind, or animals.
• Germination occurs when seeds grow into seedlings in suitable conditions.

What is Pollination?

• Pollination is the process where pollen grains, containing male plant gametes, are transferred from the stamen to the stigma.
• Pollination can be facilitated by wind, water, insects, birds, or other animals.
• Once pollen reaches the stigma, it germinates and fertilizes the ovule.
• Formation of seeds and fruits depend on this.
• Pollination is essential for plant reproduction and survival.

Types of Pollination

• Wind pollination involves ripe flowers that scatter pollen, which the wind carries to other flowers.
• Insect pollination involves pollen sticking to the insect's body before it flies to other flowers and deposits the pollen on the stigma.
• Self-pollination is from the anther of a flower to the stigma of the same flower.
• Cross-pollination is from the anther of a flower to the stigma of another flower on a different plant of the same type.
• Artificial pollination involves pollen taken from one flower and placed by hand onto the receptive stigma of another flower.

Double Fertilization

• Pollen tube forms when a pollen grain lands on a flower's stigma.
• One cell initiates pollen tube formation, which grows towards the ovary and carries the sperm-producing cell.
• Sperm Cell Production: the sperm-producing cell divides to produce two sperm cells.
• Two fusions of male and female nuclei: two sperm cells are released as it pushes its way into the embryo sac.
• One sperm cell fertilizes the egg cell.
• The other fuses with the central cell of the embryo sac.
• Endosperm and Zygote formation: The fertilized egg cell develops into a diploid zygote for embryo formation.
• The fusion of sperm and the central cell results in a triploid endosperm cell.
• With plant double fertilization, energy to produces a food source only happens when a zygote is produced.

From Ovule to Seed

• Cotton seed production occurs when the zygote undergoes mitosis, which results in the formation of proembryo and suspensor.
• The embryo develops seed coat, endosperm, shoot tip and cotyledons.

From Ovary to Fruit

• While the seeds are developing from ovules, the flower's ovary is developing into a fruit, protecting the enclosed seeds.
• Fertilization triggers hormonal changes causing the transformation.
• Fruit development occurs when the ovary wall becomes the pericarp which is the wall of the fruit.

Developmental Origin of Fruits

• Simple fruits come from one carpel or multiple fused carpels of a single flower.
• Examples include peas, lemons, and peanuts.
• Aggregate fruits develop from many separate carpels of one flower.
• Examples include raspberries, blackberries, and strawberries.
• Multiple fruits develop from many carpels of the many flowers that form an inflorescence.
• Pineapple and fig are examples.
• Accessory fruits are developed largely from tissues other than the ovary.
• The ovary is embedded in a fleshy receptacle, example is the apple.

Animal Reproduction

• Asexual reproduction creates new individuals through genes from a single parent, without fusing egg and sperm.
• Sexual reproduction is the creation of offspring by fusing haploid gametes to form a diploid zygote.
• The female gamete or unfertilized egg, known as an ovum, is relatively large and non-motile.
• The male gamete, sperm, is generally smaller and motile.
• Animals that reproduce sexually increase genetic variability by combining genes from parents, which enhances reproductive success.
• Asexual reproduction helps isolated animals reproduce and populate habitats quickly.
• Asexual reproduction is beneficial in stable environments as successful genotypes are preserved.

Mechanisms of Asexual Reproduction

• Fission involves the separation of a parent organism into two or more individuals of equal size.
• Budding involves new creatures originating from outgrowths.
• Fragmentation involves the body breaking into several pieces, which develop into adults.
• Regeneration includes regrowth of lost body parts, usually with fragmentation.

Types of Asexual Reproduction

• Binary Fission: A single cell splits into identical daughter cells (bacteria)
• Fragmentation: a parent body breaks into smaller parts to grow (Hydra)
• Regeneration: damaged cells or body parts are replaced (Starfish)
• Budding: A new organism grows from an outgrowth (Hydra)
• Vegetative Propagation: New plant grows from a fragment of its parent (Plants)
• Sporulation: Adult organisms produce spores that grow into adults (Bacteria)
• Parthenogenesis: development without fertilization (Reptiles)
• Apomixis: the asexual creation of seeds without meiosis and fertilization (Plants)

Mechanism of Sexual Reproduction

• Internal Fertilization: Male delivers sperm into female's body where it fertilizes the egg internally.
• Most terrestrial animals and some fish perform this.
• External Fertilization: Eggs and sperm are released simultaneously into the water.
• Many fish and amphibians perform this.

Some Reproductive Variations

• Metagenesis shows how animals switch between asexual and sexual generations, which happens in diploid organisms..
• Parthenogenesis is when an unfertilized egg develops into an adult animal, but happens in some species in order to maintain social order.
• Hermaphroditism is when an organism produces both eggs and sperm and may copulate with another organism.

Human Reproduction

• Consequences of pre-marital sex include unwanted pregnancy, STDs, affect schooling, social stigma, guilt, poverty
• Early pregnancy remains prevalent in the Philippines.
• Human reproduction is managed differently in males and females

Female Reproductive Anatomy

• The female reproductive system includes external structures which include the mons pubis, clitoris, labia majora/minora
• Internal reproductive organs include: The ovaries, oviducts (fallopian tubes), the uterus, the cervix and the vagina
• Functions of the female reproductive system: Sexual stimulation, protection, and lubrication.
• The inner vulva has a thin-walled chamber that serves as the birth canal and sperm repositor during copulation. Mammary glands are also present in both sexes and normally function only in women.

Male Reproductive Anatomy

• Male reproductive anatomy includes penis, scrotum, and testes.
• The testes consist of seminiferous tubules where sperm form and are surrounded by layers of connective tissue.
• The production of normal sperm cannot occur at normal body temperatures, held outside the abdominal cavity in the scrotum.
• From tubules, sperm pass into the epididymis.
• During ejaculation, sperm propels from the epididymis and ejaculatory ducts open into the urethra.

Human Sexual Response

• Two types of physiological reactions include:
• Vasocongestion is the filling of blood of increased blood flow to an area, and
• Myotonia is increased muscle tension of both skeletal and smooth muscles.
• The four phases of human sexual response include excitement phase, plateau phase, orgasm phase, and resolution phase.
• The human sexual response cycle includes arousal, plateau, orgasm, and resolution phases.

Contraception and its Types

• Contraception aims includes barrier methods, hormonal and surgical methods to avoid pregnancy
• Birth control options include sterilization, hormonal, and barrier methods.
• Abstinence remains as the only guaranteed way to avoid pregnancy and be safe.

Plant Development

• Plants capture sunlight energy for food storage and release.
• They compose over 99% of the planet's living matter.
• Tracheophytes contain leaves, stems, and roots.
• Development and the body plan are laid down before the seed leaves the plant

Seeds

• Gymnosperms: Means having naked seeds that aren't enclosed like conifers
• Angiosperms A plant that has flowers and produce seeds.
• Angiosperms divided into the monocots and the dicots on the basis of seed structure

Monocot Seed

• The Monocot include grasses and are surrounded by a protective seed coat called seed coat.
• Structure includes the aleurone layer that functions in as a digestive organ in seed germination.
• They consist of starchy endosperm and the embryo is demarked by a tough scutellum

Dicot Seed

• The dicot seed have two cotyledons.
• Also have food storage organs over endosperm and contain the radicle and the plumule
• The embryo and cotyledon is a product of of two distinct fertilizations, where structures above the cotyledons are called the hypocotyl and epicotyl

Seed Germination

• The embryo is then kept in a cycle called the dormancy, which is used to suspend the growth until Germination.
• Dormancy is broken down by releasing the gibberellin that diffuses through the seed to create enzymes that break down the stores of food for the seeds to grow.

Early Root and Emergence

• Microscopic examination of the root will disclose cap which is used to protect the tissues.
• The part of the root tip is known as the zone of divison and also has apical meristem a growing tip of embryonic.
• New cells are then sent by mitosis that continue indefinitely.

Meristems and Buds

• Primary Meristems give rise to the primary tissues that help develop different stems of the plant and grow.

Leaf Growth

• They Originate from the meristem and continue to grow.

Leaf Fall

• Leaves are in all plants and some cases may senesce and become old.

The Ecology of Abscission

The process in which plants shed one part of themselves and the absicission layer represents any adaptation that permits the loss of leaves.

Secondary Growth

• In dicots root and stem meristems give rise to any process of differentiation.

Secondary Growth

• Secondary growth usually doesn't occur in monocots but the tree such as bamboo tend to remain the same.

Animal Development

• The zygote is fertilized and is able to give cell types needed for development.
• The cytoplasm contains yolk and is able feed the developing embryo and does not contain yolk in in humans.

Cleavage: From One Cell to Many

• Rapid mitosis begins in the cleavage where 24 hours after the human fertilizations and there are 2 cells to start in mitosis.

The Blastocyst

Blastocysts, or blastulas, are hollow balls of cells surrounded by nutritive membranes that contain the embryo.

Implantation

• Implantation begins in the uterus lining of the seventh day and enzymes destroy tiny maternal capillaries present in the uterus.

Formation of Germ Layers

• Inner cell mass of the blastocyst form to make to layed disc.
• As well as the endoderm and the ectoderm and even the mesoderm.
• Which will become germ layers and give rise to the structures in the vertebrate embryos.

Stages in the Human Life Cycle

• Lists the different stages of human life such as infancy, childhood, adolescence, and older.

Plant Nutrition

• It contains water, carbon, oxygen, and hydrogen that allow plants to synthesize proteins from fats and what is needed for plants to stay alive.

Plant Nutrient Requirements

• An organism requires requirements for the maintenance to occur between these two which is essential for plant nutrient.

The Macronutrients

• Macrosutrient needed by plants in relative big amounts to benefit the plants.

The Macronutrients

• Potassium helps maintain the membrane potential.
• Phosphorus: essential for things such atp, nucleic acids, flowering, fruit, and development.

The Macronutrients

• Sulfur is an essential component of protein, sulfur comes in essential component of a amino acid.
• Is as well required for the action of many enzymes and is also needed in chlorophyll.

The Micronutrients

• Is as Vital as macronutrients but helps with the growth and all of these combined help maintain the plants health.

Routes for the Absorption of Water and Minerals Across Plant Roots:

• A. Symplast route – mineral absorbed through plasmodesmata
• B. Apoplast route - mineral absorbed along cell walls

Specialized Absorptive Structures

• A. Root hairs - used to extend the surface area that is available.
• B. Root Modules, localized swelling in roots.
• C. Mycorrhizae - Symbiotic interaction with fungus.

Nutritional Adaptation By Plants

• Symbolisis and interaction of plants and soil with the key components of the legumes.

Nutritional Adaptation by Plants

• Nutrient uptake and the symbilitctic process between fungi and nutrients

Nutritional Adaptation

• Some plants, such as the dodder, lack leaves and attach to the host using suckers that connect to its vascular system. These are holoparasites, parasites that are essential for the loss of leaves on the host.

Animal Nutrition

• A unit to indicates the amount of energy contained in food.

Nutritional Requirements of Animals

• There are three categories of animals such as carbohydrates, proteins and different components.

Essential Nutrients.

• Needed for the synthesis of any organisms and include different components that contain high levels of minerals.

Food Uptake in cells via the types of endocytosis

• Involves three process first the cell absorbs through phagocytosis, pinocytosis, and endocytosis.

Types of animals based on feeding Mechanisms

• Includes animals that live in these systems of four and are considered different feeds such as substrate, filter, fluid, and bulk.

Different Kinds of Digestive Compartments in Animals

• The three kinds of digestive compartments are food vacoules, gastrovascular activity and other complete digestive system

The Human Digestive System

• Consists of these different steps first and is used to ingest and use the other products used to digest the molecules.