Kingdom Animalia Exam Cram Notes

Kingdom Animalia and General Animal Characteristics

• Eukaryotic:
  • Animal cells have nuclei.
  • Complex cells.
• No Cell Walls:
  • Animal cells lack a cell wall, contributing to their mobility.
• Multicellular:
  • All animals are multicellular organisms.
• Heterotrophic:
  • Animals consume food to harness energy.
• Motile:
  • All animals are motile at some point in their life cycle, even if sessile as adults (stuck in one place).

Differences Between Animals and Plants

• Mobility:
  • Plants are generally immovable, except for growth movements like phototropism (leaning towards the sun) or thigmotropism (growth through touch).
  • Animals can move from place to place at some point in their life.
• Food Production:
  • Plants produce their own food through photosynthesis (autotrophs).
  • Animals are heterotrophs and must consume food for energy.
  • Plants have chloroplasts and chlorophyll, which animals lack.
• Mitochondria:
  • Both plants and animals have mitochondria for cellular respiration.
  • Plants break down sugars to make ATP.
• Cell Walls:
  • Plants have cell walls; animal cells do not. This affects mobility and structure.
• Multicellularity:
  • Both plants and animals are multicellular.

Evolution of Animals from Protists

• Protists as Ancestors:
  • Plants evolved from plant-like protists (e.g., single-celled algae).
  • Animals evolved from animal-like protists (e.g., amoeba).
  • Fungi evolved from fungi-like protists (e.g., mildew).
• Animal-Like Protists:
  • Amoebas are single-celled protists that are movable, lack cell walls, and are heterotrophic.
  • These eventually evolved into multicellular animals.

Body Symmetry in Animals

• Asymmetrical:
  • Absence of symmetry (e.g., sponges, corals).
  • No consistent shape or structure.
• Radial Symmetry:
  • Can be cut in multiple ways around the center, and each part will be similar (e.g., hydra, jellyfish).
  • Allows for sensing the environment in all directions.
• Bilateral Symmetry:
  • If cut in half from top to bottom, the right and left sides are fairly equal (more complex animals).
• Cephalization:
  • Concentration of nervous tissue (brain, sensory organs) at one end of the body (the head).
  • Example: Earthworms have a brain and eye spots at the anterior end.

Anatomical Positions for Bilaterally Symmetrical Animals

• Quadrupedal Animals (Walk on Four Legs):
  • Anterior: Head end.
  • Posterior: Tail end.
  • Dorsal: Back.
  • Ventral: Belly.
• Bipedal Animals (Walk on Two Legs):
  • Ventral (belly side) is the same as anterior (front).
  • Posterior (rear end) is the same as dorsal (back).

Homeostasis

• Definition:
  • The body's ability to maintain a stable internal balance.
• Involvement of Body Systems:
  • Body systems work together to maintain homeostasis.
• Example: Blood Sugar Regulation:
  • High blood sugar involves the digestive system (food intake) and circulatory system (sugar absorption).
  • Nervous and endocrine systems recognize the imbalance.
  • The nervous system signals the pancreas (endocrine).
  • Pancreas releases insulin (hormone).
  • Insulin tells cells (muscle, liver) to take sugar out of the blood for storage.
  • This lowers blood sugar back to a normal set point.

Macromolecules and Digestion

• Breakdown to Subunits:
  • Macromolecules (polymers) are broken down into their smallest subunits (monomers) before absorption.
• Proteins:
  • Broken down into amino acids.
• Carbohydrates:
  • Broken down into monosaccharides.
• Lipids:
  • Broken down into fatty acids (still relatively large).
• Nucleic Acids:
  • Broken down into nucleotides.

Mechanical vs. Chemical Digestion

• Mechanical Digestion:
  • Involves physical movement to break down food.
  • Examples: chewing, churning in the stomach, segmentation in the intestines (muscle movements).
• Chemical Digestion:
  • Uses chemicals (enzymes) to break down food into the smallest subunits.
  • Enzymes catalyze hydrolysis reactions to break polymers into monomers.

Role of Enzymes in Digestion

• Enzymatic Hydrolysis:
  • Enzymes break down large molecules into smaller molecules by adding water (hydrolysis).
  • Enzyme + Substrate \rightarrow Products

Types of Consumption

• Filter Feeding:
  • Water flows through the organism, and they filter out tiny nutrients (e.g., sponges).
  • Often sessile organisms.
• Suspension Feeding:
  • Organisms keep their mouths open and filter nutrients from the water (e.g., baleen whales).
• Substrate Feeding:
  • Organisms eat as they move through a substrate, like soil or leaves (e.g., caterpillars, earthworms).
• Fluid Feeding:
  • Organisms suck fluids from other organisms (e.g., mosquitoes).
• Bulk Feeding:
  • Organisms eat large quantities of food and then digest it internally.

Role of the Epiglottis in Digestion

• Function:
  • The epiglottis is a flap of cartilage in the throat that prevents food from entering the trachea (windpipe) during swallowing.
• Mechanism:
  • When swallowing, the epiglottis closes over the trachea opening, directing food into the esophagus.

Peristalsis

• Definition:
  • A series of involuntary smooth muscle contractions that move food through the digestive tract.
• Occurrence:
  • Occurs throughout the entire digestive system, starting in the esophagus.
  • Also occurs in the stomach, small intestine, and large intestine.

Digestion and Absorption in the Small Intestines

• Most Digestion and Absorption:
  • The small intestine is the primary site for digestion and absorption.
  • Releases digestive enzymes to break down molecules into smaller components.
• Villi:
  • The small intestine is lined with villi (finger-like projections) that increase surface area for absorption.
  • Villi contain capillaries for nutrient absorption into the bloodstream.

Digestive Enzymes

• Pepsin:
  • Enzyme in the stomach that breaks down proteins.
• Amylase:
  • Enzyme that breaks down complex sugars (carbohydrates) into smaller sugars.
  • Salivary amylase (mouth) and pancreatic amylase (small intestine).
• Lipase:
  • Enzyme that breaks down lipids.
  • Gastric lipase (stomach) and pancreatic lipase (small intestine).
• Nuclease:
  • Enzyme that breaks down nucleic acids.
  • Released in the small intestine.

Excretory Systems

• Urinary System:
  • Gets rid of nitrogenous waste through urine; filters blood.
• Digestive System:
  • Gets rid of solid waste from undigested and unabsorbed food.
• Respiratory System:
  • Gets rid of gaseous waste (carbon dioxide).
• Integumentary System:
  • Gets rid of excess water and salts through sweat.

Structures of the Urinary System

• Kidneys:
  • Filters blood to remove waste.
• Ureters:
  • Tubes that carry urine from the kidneys to the bladder.
• Bladder:
  • Muscular organ that stores urine.
• Urethra:
  • Tube through which urine is released from the bladder.

Respiratory and Circulatory Systems

• Site of Gas Exchange in the Lungs:
  • Alveoli are tiny air sacs in the lungs where gas exchange occurs.
  • Alveoli are covered by capillaries.
  • Oxygen diffuses from the alveoli into the bloodstream; carbon dioxide diffuses from the bloodstream into the alveoli.

How Respiratory and Circulatory Systems Work Together

• Respiratory System:
  • Takes in oxygen.
• Circulatory System:
  • Transports oxygen to body tissues.
  • Oxygen is picked up in the lungs (alveoli) and diffuses into the bloodstream.
  • Arteries carry oxygenated blood from the heart to the body.
  • Blood picks up carbon dioxide (waste) from body tissues.
  • Veins carry deoxygenated blood back to the heart, which pumps it to the lungs to be exhaled.

Types of Blood Vessels

• Arteries:
  • Carry blood away from the heart.
• Veins:
  • Carry blood toward the heart.
• Capillaries:
  • Small vessels connecting arteries and veins.
  • Site of perfusion (exchange of materials between blood and tissues).

Perfusion

• Definition:
  • Exchange of materials between the blood and surrounding tissues, occurring at the capillaries.
• Examples:
  • Gas exchange in alveoli (oxygen into blood, carbon dioxide out).
  • Exchange of materials in nephrons within the kidneys.

Oxygenated vs. Deoxygenated Blood

• Oxygenated (Oxygen-Rich) Blood:
  • Bright red color.
  • Normally found in arteries, except for pulmonary arteries.
• Deoxygenated (Oxygen-Poor) Blood:
  • Dark maroon color.
  • Normally found in veins, except for pulmonary veins.
  • Blood is always red (not blue) because hemoglobin is red.

Open vs. Closed Circulatory Systems

• Open Circulatory System:
  • Blood is not always contained in vessels.
  • Heart pumps blood into open-ended arteries; blood douses organs and tissues.
  • Heart sucks deoxygenated blood back up.
  • Found in many insects.
• Closed Circulatory System:
  • Blood is always contained in vessels (heart, arteries, capillaries, veins).
  • Found in earthworms and humans.

Reproduction and Animal Development

• Inheritance of Mutations:

  • Asexual Reproduction: Offspring have the exact genetics of the parent, including any mutations.
    Mutation \rightarrow Offspring
  • Sexual Reproduction: Mutations must be in the sperm or egg to be passed on.

• Types of Asexual Reproduction:

  • Fragmentation: An animal can be cut up, and each piece grows into a new animal (e.g., flatworms).
    Fragment \rightarrow New \ Animal
  • Budding: A small offspring grows off the adult and detaches to grow independently.
    Bud \rightarrow Offspring
  • Parthenogenesis: The female chemically fertilizes her own egg to produce offspring.

• Types of Sexual Reproduction Patterns:

  • External Fertilization: Eggs and sperm unite outside the body (in water).
  • Internal Fertilization: Sperm fertilizes the egg inside the female.
  • Hermaphrodites: Organisms that make both eggs and sperm and can fertilize their own eggs. Common in sessile animals like coral.

• Structures of the Female Reproductive System:

  • Cervix: Entryway into the uterus that dilates during childbirth.
  • Uterus (Womb): Muscular organ where the fertilized egg attaches and grows.
  • Ovaries: Reproductive glands where eggs and hormones (estrogen, progesterone) are produced.
  • Fallopian Tubes: Tubes that catch ovulated eggs and transport them to the uterus.
  • Vagina: The female sex organ, also called the birth canal.

• Ovulation:

  • The monthly release of a mature egg from the ovary.

• Fertilization:

  • The union of sperm and egg, forming a zygote/fertilized egg.
  • Naturally occurs in the fallopian tube.

• Peristalsis in Reproductive Systems:

  • Involuntary smooth muscle contractions.
  • Female: Moves the egg through the fallopian tube to the uterus.
  • Male: Moves sperm up the vas deferens.

• Stages of Animal Embryonic Development:

  • Fertilization:
    • The fusion of sperm and egg
  • Cleavage:
    • Cell division (keeping cells attached).
    • Cell \ Division
  • Morula:
    • Solid ball of cells (16+ cells).
    • Solid \ Ball \ of \ Cells
  • Blastula:
    • Single layer of cells with a fluid-filled center.
    • Single \ Layer \ of \ Cells + Fluid \ Filled \ Center
  • Gastrulation:
    • One side of the blastula caves inward, forming a two-layered structure (gastrula).
    • Cave \ Inward \ Two \ Layered

• Three Germ Layers:

  • Ectoderm: Outer layer of cells.
    • Becomes skin and nervous tissue (brain, nerves).
  • Endoderm: Inner layer of cells (formed during gastrulation).
    • Becomes the digestive tract, respiratory, excretory, and reproductive tracts.
  • Mesoderm: Middle layer of cells (forms between ectoderm and endoderm).
    • Becomes the skeletal, muscular, and circulatory systems.
    • Skeletal + Muscular + Circulatory \ Systems

• Protostomes vs. Deuterostomes:

  • Protostomes: The blastopore (opening formed during gastrulation) becomes the mouth first.
  • Deuterostomes: The blastopore becomes the anus first, and the mouth forms later.