Introduction to Zoology

• Zoology is the branch of biology focused on the study of animals.
• The study of Zoology involves the examination of animal structure, function, evolution, and classification.
• Zoology includes numerous subfields exploring varied aspects of animal life

Different Branches of Zoology

• Structural and Functional Zoology studies animal forms at different levels.
• Morphology is the study of form and structure.
• Anatomy is the study of the animal's body structure.
• Histology is the study of tissues.
• Cytology is the study of cells.
• Physiology is the study of the function of the body.
• Developmental Zoology includes;
• Embryology, the study of the development of the embryo
• Evo-Devo is the study of the genetics of development.
• Taxonomic Zoology deals with classification;
• Systematics establishes evolutionary relationships.
• Nomenclature assigns scientific names.
• Evolutionary and Ecological Zoology includes;
• Evolutionary biology, the study of the development of life.
• Ecology, the study of the environment.
• Biogeography, the study of species across geological space and time.
• Behavioral Zoology studies;
• Ethology is research on animal behavior.
• Sociobiology, the study of the genetics of animal interactions .
• Applied Zoology encompasses practical applications.
• Veterinary science ensures animal health.
• Animal husbandry manages domestic animals.
• Wildlife biology focuses on conservation.
• Entomology studies insects.
• Major Zoological Branches include;
• Parasitology studies parasites.
• Ichthyology studies fish.
• Herpetology studies reptiles and amphibians.
• Ornithology studies birds.
• Mammalogy studies mammals.
• Entomology studies insects.
• Malacology studies mollusks.
• Helminthology studies worms.

Famous Zoologists

• Aristotle, the "Father of Zoology," classified animals by characteristics and studied anatomy, reproduction, and behavior.
• Carl Linnaeus developed binomial nomenclature and the basis for modern taxonomy.
• He is also the author of Systema Naturae.
• Charles Darwin developed the theory of evolution by natural selection.
• He also authored On the Origin of Species.
• Gregor Mendel, "Father of Genetics," studied inheritance patterns in pea plants
• Provided the foundation for modern genetics.
• Thomas Henry Huxley, known as "Darwin's Bulldog," studied human-ape relationships
• He contributed to comparative anatomy and paleontology.
• Richard Dawkins proposed the Selfish Gene theory and is an advocate for evolutionary biology and zoological genetics.
• Jane Goodall, a primatologist and ethologist, researched chimpanzees in Tanzania
• She is an advocate for conservation and animal welfare.

Importance of Zoology

• Understanding biodiversity and animal conservation is aided by Zoology.
• Advancements in medical and pharmaceutical research are helped by Zoology.
• Ecological balance and wildlife management are maintained with its knowledge.
• Zoology plays a role in supporting advances in genetics, evolution, and biotechnology.

Plant & Animal Cells

• Objectives include describing a structure of a typical cell, locating and drawing visible parts of cells under a microscope, and comparing plant and animal cells.

Cell - Basic Structural and Functional Unit of Life

• Cytology is the field of biology focused on the study of cells.

Timeline in the Discovery of Cells

• Robert Hooke discovered cells in 1665 and observed tiny compartments in cork slices and called them "CELLS".
• Robert Brown described the nucleus as a constant component of cells in 1833
• Felix Dujardin discovered protoplasm, the substance filling the cell that is actively flowing or streaming, in 1835.
• Hugo von Mohl discovered and described chloroplasts in 1837.
• Albert von Kolliker discovered mitochondria in 1857.
• Matthias Schleiden examined plant parts and concluded that "all plants are made up of cells" in 1838.
• Theodor Schwann examined animal parts and concluded "all animals are made up of cells" in 1839.
• Rudolf Virchow discovered cell division and proposed that "cells come from the division of pre-existing cells" in 1855.
• Walther Flemming discovered asters and chromatins in dividing cells in 1878
• Pierre Joseph Van Beneden discovered meiosis, a type of cell division observed in the egg and sperm cells of worms, in 1883.
• Camillo Golgi discovered the Golgi apparatus while studying cross-sections of a spinal cord in 1898.
• Emilio Veratti discovered the endoplasmic reticulum while observing a striated muscle cell in 1902.
• Johannes Rhodin discovered microbodies from mouse kidney cells in 1954.
• Dr. Christian de Duve discovered the lysosome while studying liver cells in 1955
• Microbodies were isolated that function as peroxisomes, containing hydrogen peroxide-metabolizing enzymes, in 1965.

The Cell Theory

• All organisms are composed of cells.
• The cell is the basic unit of structure and function in living things.
• Cells come from pre-existing cells and can be cultured in vitro or in vivo.

Types of Cells Composing Living Things

• Unicellular organisms consist of only one cell, capable of performing all life processes.
• Multicellular organisms consist of multiple cells and can perform distinct life processes separately.

Unicellular vs. Multicellular Organisms

Prokaryotic vs. Eukaryotic Cells

• Prokaryotic Cells
• Lack membrane-bound organelles.
• Contain no bound neucleus.
• Usually unicellular.
• They range from isze 0.1-5 micrometers.
• Most have a cell wall.
• Primarily use asexual reproduction.
• Eukaryotic Cells
• Possess membrane-bound organelles.
• Contains true nucleus.
• Exhibit unicellular or multicellular forms.
• Ranges from 10-100 micrometers .
• Asexual and sexual Reproduction.

Cell Wall Structures

• A nonliving component of plant cells composed of cellulose (a polysaccharide).
• Its is for mechanical support and maintaining cell shape.

Plasma Membrane

• The plasma membrane is flexible and elastic.
• Double layers of phospholipids, proteins, carbohydrates and steroids.
• It regulates the entry/exit of materials through selective permeability.

Mitochondrion Structures

• Double-membrane structure with inner membrane folds (cristae).
• Is the "powerhouse of the cell"
• Provides energy in the form of ATP (adenosine triphosphate).

Organelles

• Small, membrane-bound structures carry out specific functions for life.
• They exist in various shapes and sizes
• Organelles are embedded or free-floating in the cytoplasm.

Organelles: Vacuole

• In animal cells, there are several small vacuoles
• Used for storage.
• Contain nutrients, water, or waste,
• Plant cells contain one large central vacuole.
• For storing water to push agains the cell wall
• Keeps the plant rigid.

Vacuole Structures

• covered membrane tonoplast
• compartment separated by a single membrane.

Vacuole Functions

• Stores water, food, or waste.

Cytoplasm Structures

• A complex fluid filling the cell
• Outer cytoplasm is gel-like; inner cytoplasm is fluid.

Cytoplasm Functions

• The matrix for different cell organelles.
• Allows distribution of materials because of cyclosis.

Nuclear Membrane Structures

• A doubled-layer membrane encloses the nucleus.

Nuclear Membrane Functions

• Seperates the nuclear contents from the cytoplasm.

Nucleolus Structures

• It has dense, spherical body inside the nucleus. Contains the nucleic acid RNA.

Nucleolus Functions

• Responsible for the RNA synthesis and ribosome production.

Nucleoplasm Structures

• Gel-like material fills the nucleus and functions as the matrix for chromosomes.

Nucleoplasm Functions

• Part of chromosomes nucleolus structure.

Chromosomes Structures

• Highly coiled structures that create a network over the nucleoplasm.

Chromosomes Funnctions

• Transmits hereditary characteristics via genes.

Endoplasmic Reticulum Structures

• Network of channels comprised of a single membrane.
• May be bumpy with ribosomes (Rough ER) or smooth (SER)

Endoplasmic Reticulum Functions

• Its is a double membrane structure that may be smooth or contain ribosomes.

Chloroplast Structures

• Double-membrane structure containing chlorophyll pigments.

Chloroplast Functions

• Chlorophyll, the green pigment, enables photosynthesis.

Lysosome Structures

• Single-membrane compartment containing hydrolytic enzymes
• Refered to as the "suicide bag of the cell"

Lysosome Functions

• Breaking down cellular waste

Centrioles Structures

• Two small rods at right angles
• Each rod has microtubules like the spokes of a wheel.

Centrioles Functions

• Forms spindle fibers during cell division
• Acts as an anchor for the cytoskeleton.

Ribosomes

• Attached to the endoplasmic reticulum
• Use RNA synthesized by the nucleolus to synthesize specific ammino acids
• Referred to as the "protein factories" of the cell.

Plant Cell vs Animal Cell

• Plant cells have a cell wall allowing them to have a fixed shape while animal celles don't
• Animal cell have numerous samll valcuoles wheil plant cells only have one larger
• Only plant cells have chloroplast
• Animal cells dont have chloroplast while, plant cells lack centroleso and lysomones.

Golgi Apparatus Structures

• It is the stack of single membranes that are connected to the plasma membrane and endoplasmic reticulum.

Golgi Apparatus Functions

• Functions in sorting, packaging and secreting materials; it is also involved in the processing and modification of proteins.

Historical Cell Structure Knowledge

• Robert Hooke used a microscope to view cells in 1665.
• He examined cork and the small boxes looked like cells.
• Hooke named them cells.

CELL STRUCTURE AND FUNCTION

• In 1673, Leeuwenhoek (a Dutch microscope maker), was first to view organism (living things)
• Leeuwenhoek used a simple, handheld microscope to view pond water & scrapings from his teeth
• In 1838, a German botanist named Matthias Schleiden concluded that all plants were made of cells.
• In 1839, German zoologist named Theodore Schwann concluded that all animals were made of cells.
• In 1855, German medical doctor named Rudolph Virchow observed, cell division
• Basic Cell Info

Parts and Function of Prokaryotic cells

• Pili is the outer hair like surface
• Capsules is the first of 3 layers followed by the cell wall
• The Cell wall is the layer that is in the middle, between the capsule and the plasma membrane.
• The Plasma Membrane is the most inside layer that protects the cytoplasm and other components.
• Ribosomes synthesize proteins.
• The Nucleotide is where DNA is located
• The plasmid id the small segment of DNA, that is not attached to the nucleotide region. Its the extra DNA
• Flagellum moves cells.

Parts and Function of Eukaryotic cells

• • It has three layers surrounding it, with a hydrophilic phosphate head facing out and a hydrophobic lipid tail facing in.

Mitocondria

• “power house of the cell”
• a membranous sac with many internal compartments
• Generate cellular energy
• Both plants & animal cells have mitochondria
• Site of CELLULAR RESPIRATION (burning glucose)

Endoplasmic Reticulum

• Site for protein synthesis, this is also called transport mechanism of the cell.

Two types of ER

• Rough endoplasmic reticulum (RER).
• Smooth endoplasmic reticulum (SER).

Ribosomes

• particles composed of protein and RNA.
• site for protein synthesis; this is the surface that attaches to the endoplasmic reticulum or free in the cytoplasm.

Nucleus

• Contains genetic material in the form and structure of DNA molecules that are organized into structure of DNA molecules that are organized into structure called chromosomes

Explore the fundamentals of zoology, its subfields like ethology and taxonomy, and its impact on society. Learn about cell biology including meiosis, tissues, and key organelles. Delve into the functions of animal bodies and wildlife management.