Hypostome and mouth/anus are surrounded by the tentacles
Cnidocytes, stinging cells, function in defense or capturing of prey
Cnidocytes contain nematocysts, which are known as the stinging cells
lack a digestive system and have intracellular digestion
digest food inside their individual body cells through phagocytosis, or the infolding of the cell membrane
Water circulates the food, oxygen, and waste removal, which goes out through the ostia, into the spongocoel, and out the osculum
possess a gastrovascular cavity and have extracellular digestion
digest food in their gastrovascular cavity, which is a single opening that serves as the mouth and anus
gastrovascular cavity is a significant advancement because it allows larger food particles to be digested, compared to the intracellular digestion of sponges
Body Advances Sponges Cnidaria Symmetry Absent Radial Digestive System Absent Gastrovascular Cavity Support Endoskeleton Hydrostatic Skeleton Nervous System Absent Nerve Net Tissues Absent Present Germ Layers Absent Two
The sponges lack symmetry, tissues, and both a digestive and nervous system. The little support they have is through an endoskeleton. Cnidarians have symmetry (radial), a digestive system (gastrovascular cavity), a nervous system (nerve net), and tissues. The nerve net is the most basic nervous system, consisting of neurons without a central control organ, which sends messages to muscle cells. They also have better support than the sponges in the form of a hydrostatic skeleton, which is a fluid-filled body cavity that is surrounded by muscles. Cnidarians also possess two embryonic germ layers made up of ectoderm and endoderm.
Eye Spots Auricle * Pharynx and gastrovascular cavity not visible
Planaria have three germ layers present: ectoderm, endoderm, and mesoderm, compared to Hydra, who only have ectoderm and endoderm. The mesoderm that planaria possess allows for more sophisticated organs to develop. planaria also possess an incomplete digestive system with one opening that serves as both the mouth and anus. Digestion occurs in the gastrovascular cavity, which is reached through the pharynx. The incomplete digestive system of planaria is an evolutionary advancement because it prevents continuous feeding from occurring. Another advancement is the excretory system, which consists of protonephridia, which are lateral canals, with branches that are capped by flame cells. This particular excretory system allows for osmotic balance between the planaria and their surroundings. Finally, planaria exhibit sensory cells in their auricles and light sensitive eyespots, which lead to a more centralized nervous system, serving as the early development of a brain. The brain consists of cerebral ganglia, which receives messages from the sensory cells, and leads to nerve cords that run laterally along the body.
Epidermis Pharnyx & Gastrovascular Cavity
Planaria have a pharynx that leads to the gastrovascular cavity. The gastrovascular cavity splits into branches, enabling nutrients to be distributed throughout the entire body. These sections are therefore that branched parts of the gastrovascular cavity.
Planaria lack a respiratory or circulatory system meaning they must obtain oxygen by diffusion. Earthworms on the other hand have a closed circulatory system and blood with hemoglobin in order to transport oxygen.
Movement is due to segmentation.
Earthworms have longitudinal and circular muscles, which compact and contract. Each segment elongates as it contracts against the hydrostatic skeleton.
Earthworms possess long and circular muscles that contribute to their movement. The circular muscles in a segment contract, elongating the segment. When the longitudinal muscles in a segment contract, the segment compacts. The muscle contraction of the circular, then longitudinal muscles enable movement in an earthworm. These muscular contractions differ from planaria, which move in a gliding motion due to the movement of cilia on their ventral surface.
Planaria have an incomplete digestive system, while earthworms have a complete digestive system. Planaria have a digestive system, which consists of multiple parts of the gastrovascular cavity because it splits into branches. As a result of the split branches, nutrients reach all parts of the body. In contrast, earthworms have only one section of digestive tract because of their complete, unsegmented digestive system. The digestive system in an earthworm consists of the mouth, pharynx, esophagus, crop, gizzard, intestine, and anus, while planaria digestive system solely consists of the pharynx and gastrovascular cavity.
Digestive tract *Reproductive Structures: not shown
Annelids move forward by using peristaltic contractions of the circular muscle and turn by contracting the longitudinal muscles. Roundworms move using a thick layer of obliquely arranged muscle fibers just under epidermis, they lack circular muscles so motion is always undulatory. Annelid Roundworm Body cavity Coelom Pseudocoelom Segmentation Present Absent Circulatory System Closed Absent Excretory System Metanephridia Excretory gland cells Nervous System Brain, ventral nerve cord Brain, nerve cord
Annelids have a coelom, which is a fluid-filled body cavity, and segmentation, due to their circular and longitudinal muscles. They also possess a closed circulatory system and an excretory system composed of metanephridia. Annelids also have a central nervous system (brain) that is made up of ganglion and connects to a large ventral nerve cord that runs down the entire length of the body.
Roundworms have a pseudocoelom, which is a coelom that isn’t completely lined by tissue from the mesoderm. Their pseudocoelom is acts as both a hydrostatic skeleton and a circulatory system. Roundworms have a tough cuticle, made of collagen, which covers the body. They also possess only longitudinal muscles, but no circulatory muscles. As a result of no segmentation, roundworms thrash. Their excretory system is made up of gland cells, and their nervous system composes of a central nervous system (brain) and nerve cords.
Exoskeleton Legs Segments (13)
Exoskeleton is scale-like
Legs are very small, protected by body
Behavior & Movement:
Movement occurs through the few small, short legs of the sow bug that are attached to the segments.
Exoskeleton Legs Segments (3)
Six legs and two antennae
Exoskeleton covering the body
Divided into three segments:
Head, abdomen, and thorax
Behavior & movement:
Movement occurs through the six legs of the tenebrio beetle, one pair per segment.
Segmentation becomes more specialized from earthworms to sow bugs to tenebrio beetles.
Earthworms exhibit circular and longitudinal muscles in each segment.
Sow bugs have less, more specialized segments and small appendages.
Tenebrio beetles have the most specialized segmentation, consisting of three segments known as the head, abdomen, and thorax.
Segments head exoskeleton
Head Mouth parts segments exoskeleton
gonads Digestive glands
Stomach Radial canal Ring canal (underneath stomach) ampullae
Eukaryotic organisms that are heterotrophic
Majority of species grow as multicellular filaments called hyphae forming a mycelium
Sexual and asexual reproduction of the fungi is common through spores often producing fruiting bodies
Yeasts, molds, and mushrooms are examples of fungi
fungi are more closely related to animals than plants
Mycelium Culture Medium Sporangia
Many strands of clear hyphae
Hyphae are the clear strands that make up the organism, together they are form a structure known as the mycelium
Sporangia are abundant at the ends of many hyphae
Sporangia are the fruiting bodies that are produced, in this case, asexually by the Rhizopus
Mating Strain Hyphae Zygospore Sporangia
Fungal Hyphae Top of Lichen Algal Cells
Ascus and spores ascocarp
Hyphae Nematode Trap
Plants most likely evolved from green algae
Both groups have chlorophylls a and b and betacarotene as their photosynthetic pigments
Both store reserve food as starch
Both have cellulose containing cell walls
The Plantae kingdom includes mosses, ferns, conifers, and flowering plants
Nearly all plants produce their own organic molecules through photosynthesis
Alternation of generations
Plants cycle between diploid sporophyte and haploid gametophyte stages
The earliest plants in the evolutionary timeline are Bryophytes (nonvascular plants) which include mosses and liverworts
require a constantly moist environment
dominant gametophyte structure in plant
stay small and close to the ground
lack true stems, leaves and roots
Then came the vascular plants which can be divided into two categories, seedless and seed plants
Vascular plants developed a root system
Phloem and xylem (transport water/nutrients)
Seedless vascular plants include club mosses, horsetails, and ferns
Seed plants developed a more extensive root system, a more efficient vascular system, and a new adaptation in which the reproductive structure in which the gametophyte is protected inside sporophyte tissue (the seed)
Seed plants can be further separated into two groups,
Naked seed plants (such as conifers) known as gymnosperms
These leaves only have stomata on the upper surface because this leaf comes from a water lily that floats on the top of ponds. Therefore, there are no stomata on the bottom of the leaf to ensure they do not open and let water into the leaf.
The vascular tissue is reduced in the hydrophytic leaf due to the plant being surrounded by water. Because of this, the hydrophytic leaf does not need water to be sent to it from the roots but rather water diffuses into them. The mesophytic leaf on the other hand is surrounded by air causing a need for water to be transmitted from the roots up to the leaves.
Xerophytic leaf comes from plants that are native to arid environments.
To combat the lack of water available, xerophytic leaves adapt by making their epidermis and cuticle thicker, while obtaining stomata in pits. As a result of these adaptations, xerophytic leaves reduce water loss, allowing them to survive in droughts.