Simple Animals - Biology 11 - Sekulovich

What is an animal? (What Traits do they All Share)

Eukaryotic - Have nucleus and organelles

NO CELL WALL - Gotta move around gang

Multicellular - Many different and SPECIALIZED cells

Heterotrophs - CONSUME/ feed on other organisms

Describe "eukaryotic."

Their cells have a nucleus and many small parts called organelles.

Why do animal cells lack cell walls?

Because animals need to move around.

What does "multicellular" mean in the context of animals?

They are made of many different, specialized cells.

Heterotroph (Animals)

Animals don't make their own food; they have to eat other organisms.

Cell Specialization

It's when each specialized cell has a special shape, structure, and internal parts that suit its job.

Division of Labour

To be efficient, animals share out important tasks among their specialized cells to survive.

What are the 7 things animals need to do to survive?

Feeding, Respiration, Internal Transport Systems, Excretion, Response, Movement, and Reproduction.

Herbivores

They eat plants (like roots, stems, leaves, flowers, seeds, or fruits).

Carnivores

They eat other animals (like fat, muscle, bone marrow, or blood).

Parasites

They live inside or attached to another organism and feed on it (can cause disease, but sometimes helps the host).

Filter Feeders

They are water animals that strain tiny floating plants and animals from the water around them.

HUMPACK WHALES

Detritus Feeder

They eat rotting (detritus) plants and animals (they are decomposers).

WORMS

Respiration

It's the process of taking in oxygen and giving out carbon dioxide.

What is the chemical equation for respiration?

Glucose + O2 → CO2 + H2O + ATP

How do small and large animals respire?

Small animals can breathe through their skin.

Large animals need lungs/ gills with INTERNAL TRANSPORT SYSTEMS

Internal Transport System

They are systems that move oxygen, carbon dioxide, nutrients, and waste through a complex organism.

EXAMPLE: The circulatory system delivers oxygen to all body cells through blood vessels.

What is Hemoglobin?

It's a substance in mammal blood that uses iron to carry oxygen.

What is Hemocyanin?

It uses copper (Cu) to carry oxygen

What is Excretion?

It's how the body gets rid of toxins that are produced during bodily processes.

How do small/ large animals excrete waste?

Small animals rely on diffusion to get rid of waste from their tissues into the water around them.

Larger animals need special systems to remove wastes from their bodies.

Why do animals need a "Response" system?

Animals need to spot danger (predators), find food, and recognize others of their own kind.

How do animals use specialized sensory cells?

They use special sensory cells linked to the nervous system. Eyes and ears collect information from the environment by reacting to light, sound, movement, and other signals.

Sessile

They live their entire lives in one spot.

Motile

They have the ability to move around.

How do most animals move? (Systems and Tissue)

Most animals move using their muscles and bones (muscular and skeletal systems). Along with Nerves

How do Insects (Arthropods) move?

Insects don't have an internal skeleton; they move using their outer skeleton (exoskeleton).

What kind of skeleton do Reptiles, birds, and mammals have?

An internal skeleton (endoskeleton).

Asexual Reproduction.

One organism produces offspring without needing another partner.

Sexual Reproduction.

Involves combining genetic material from two parents.

Internal Fertilization

When fertilization happens inside the body.

External Fertilization

When fertilization happens outside the body.

Direct Development

Eggs hatch into tiny versions of the adults that just get bigger without changing their overall shape.

Indirect Development

Eggs hatch into larvae that look completely different from the adults. T

hey then go through metamorphosis, where they change shape dramatically (like a caterpillar becoming a butterfly).

Metamorphosis

A process where larvae drastically change shape to become adults (e.g., caterpillar to butterfly).

Embryogenesis

The process of how an embryo forms and develops.

Blastula

A hollow ball of cells formed early in embryo development.

Blastopore

An opening that forms in the blastula during gastrulation.

Gastrulation

The process during embryo development where cells move inward to form germ layers.

One-way digestive tract

If during gastrulation, cells move all the way through and create an opening at the other end.

HUMANS

Two-way digestive tract

If during gastrulation, cells do NOT completely open at the other end (like in sponges and cnidarians).

Mouth and ass same thing

Germ Layers?

Groups of cells that act as a single unit during the early stages of embryo development.

Name the three primary Germ Layers.

Ectoderm, Endoderm, and Mesoderm.

What does the Ectoderm develop into?

Skin (epidermis), nervous system, sensory parts (eyes, ears, nose tissues), glands, lower anal canal, urethra end, and tooth enamel.

What does the Mesoderm develop into?

Most muscles (except skin and iris muscles), blood, connective tissue, bone, urinary and reproductive systems (except bladder, prostate, urethra), gonads, part of the adrenal gland, teeth (except enamel), spleen, heart, and blood.

What does the Endoderm develop into?

Lining of the gut, respiratory tract cells, bladder & urethra, inner ear (tympanic cavity & auditory tube), liver ducts, thyroid gland, and pancreas.

Radial Symmetry?

Where you can draw many imaginary lines through the center of the animal, and it will be symmetrical.

Animals that do radial symmetry DO NOT HAVE A HEAD

EXAMPLE: Sea star, jellyfish, sea anemone.

Asymetry

No symmetry at all.

Bilateral Symmetry?

Where one side is a mirror image of the other.

Anterior

Front.

Posterior

Back.

Dorsal

Upper.

Ventral

Lower.

Why do animals with bilateral symmetry often have a "head"?

Animals with bilateral symmetry move forward with their front (anterior) end first. This was favored by natural selection, helping the animal survive.

Cephalization

It's when sense organs gather at the front (anterior) of the animal.

NERVE CELLS also collect there because their job is to "decide" what the animal should do.

Cephalization becomes more noticeable as animals get more complex.

Why do animals have a brain?

Brains process information and react to things in the environment. Nessacary for survival

Ganglia

Small groups of nerve cells. Primitive Brain. If a cluster big enough, then its a brain

Invertebrates

Animals without a backbone. 95% of all animals are invertebrates

What are the first evolved invertebrates?

Porifera.

Phylum Porifera

Sponges.

Are adult sponges sessile or motile?

Sessile; they are anchored to the ocean floor as adults.

How do sponges feed?

They are suspension/filter feeders.

How do sponges reproduce sexually?

Most are HERMAPHORDITES, meaning each individual functions as both female and male (producing both egg and sperm).

What type of symmetry do most sponges exhibit?

Mostly asymmetric (some show radial symmetry).

Acoelomates

They do not have a body cavity. (Fluid-Filled space that houses organs)

Do sponges have true body systems?

No, they don't have any true body systems, but they do have specialized cells. (Primitive Systems)

Why are sponges considered important in understanding early life forms?

They are among the earliest multicellular life forms, providing information about the "blueprints" of early life.

Ecological Role of Sponges

They can provide food and shelter for other organisms and have symbiotic relationships with bacteria and plant-like protists.

Name the three classes of Porifera (Sponges)

Class Calcarea, Class Hexactinellida, Class Demospongiae.

Class Calcarea

They have a CaCO3​ (calcium carbonate) skeleton, live in marine environments, are dull in color, and are less than 4 mm.

Class Hexactinellida.

Their skeleton is made from "glass" (their six-rayed spicules are made of Silicon).

Class Demospongiae.

They make up 90% of all sponges, are the largest and brightly colored, and include bath sponges and 150 freshwater species.

Osculum

A large opening where water flows out of the sponge.

Mesohyl

A thin, jelly-like space between the two cell layers of the sponge, containing a protein matrix, some cells, and spicules.

Pinacocytes

These are the "skin cells" of sponges; they are epidermal cells that form the outer lining of the sponge body wall. They are thin, leathery, and tightly packed.

Choanocytes

These cells line the inner body walls and have a central flagellum surrounded by a collar of microvilli. Their flagella beat to pump water through the sponge, and the collar is where nutrients are primarily absorbed. In some sponges, they can develop into gametes.

Archaeocytes

These are versatile cells that can change into all other types of sponge cells. They eat and digest food caught by choanocytes and transport nutrients to other cells. In some sponges, they also develop into gametes.

Sclerocytes

Cells that secrete spicules, which are structural elements of the sponge.

Myocytes and Porocytes

Myocytes and Porocytes surround canal openings. Poriferans don't have muscle cells, so their movement is limited.

T`hese cells can contract like muscle cells to control water flow through the sponge.

Spicules

These are hard structures embedded in the sponge's body wall that provide support.

Collar cells

These cells line the internal cavity and have flagella used to catch food particles.

Describe the Simple (asconoid) Canal System.

Water enters the central cavity (spongocoel) through small pore cells. The cells lining the spongocoel absorb nutrients and oxygen, and the remaining water is expelled through the osculum.

Describe the Advanced (Synconoid) Canal System.

The body wall is folded, which allows for more pores without increasing the overall size of the sponge.

Describe the Complex (Leuconoid) Canal System.

This canal system is extensively branched and more complex than the others.

How do sponges undergo asexual reproduction?

They can reproduce asexually by producing buds called gemmules.

Describe sponge sexual reproduction.

Sperm cells are released and engulfed by a choanocyte (flagella things) in another sponge.

Fertilization occurs, forming an embryo, which develops into a planktonic amphiblastula larva. This larva then settles and attaches to a surface to grow into a new sponge.

Economic Importance of Sponges

Historically, there was a large market for natural sponges in bathrooms and kitchens due to their absorbency. However, synthetic sponges have mostly replaced this industry, though real sponges are still sold to a lesser extent.

Phylum Cnidaria

JELLYFISH!! SO W

They are acoelomates (no body cavity or complex organs),

Radial symmetry, TWO germ layers (ectoderm and endoderm), two body types (polyp and medusa),Gastrovascular cavity, and a simple nervous system called a nerve net. They can reproduce sexually or asexually by budding.

What are the two germ layers in Cnidaria?

Ectoderm (for protection and movement) and Endoderm (for inner lining and digestion).

What are the two main body types in Cnidaria?

Polyp and Medusa.

Polyp

Polyps are sessile (stay in one spot), have tentacles that face up, and usually reproduce asexually (except sea anemones). Examples include sea anemones, coral, and hydra.

Medusa

Medusae are motile (can move to hunt, escape, or find mates), have tentacles that face down, and reproduce sexually. Jellyfish and sea wasps are examples.

Name the four main classes of Cnidaria.

Cubozoa (Box Jelly), Scyphozoa (Moon Jelly, Purple Jelly), Anthozoa (Coral, Anemone), and Hydrozoa (Hydra, Portuguese Man O' War).

Gastrovascular Cavity (Cnidaria)

This is the inner cavity that handles digestion, circulation, respiration, and excretion.

Unlike more complex animals, these bodily functions are not separated into specialized systems.

Mesoglea

A jelly-like layer located between the two germ layers (ectoderm and endoderm) in cnidarians.

It allows nutrients and oxygen to spread (diffuse) to all cells.

Nematocysts

Special stinging structures usually found at the ends of tentacles.

They are made of special cells called cnidocytes that contain toxic organelles (cnidocysts). When triggered, a barbed needle is released, injecting toxins into flesh. They are used to defend against predators or to attack prey.

BASICALLY STAB VENOM

Sea Anemone (Class Anthozoa) reproduction

Sea anemones (polyps) can form new polyps by budding off, which then break away (asexual reproduction) and settle on the ocean floor to form new anemones. Competing groups can attack each other, creating a "no-man's-land" between them.

Jellyfish reproduction

Jellyfish have both a polyp and a medusa stage in their life cycle. The top part of the polyp buds off to become a medusa. Polyps can reproduce asexually. The medusa then produces eggs and sperm, which are fertilized by another medusa to develop into a new polyp.

Ecological roles of Cnidarians

They filter and clean water. Corals are very important because if they die (due to increased water temperature), the ecosystems they support also die. They also form symbiotic relationships with other ocean life.

Symbiotic relationships involving Cnidarians.

Clownfish and anemones have a symbiotic relationship where clownfish clean the anemone in exchange for safety. Corals also live in symbiosis with many types of algae.