Bio Flashcards
What is biodiversity?
Variety of life on Earth, includes the range of species, genetic variations, and ecosystems
Crucial for the ecosystem’s stability and resilience
What is genetic diversity?
Variety of genes within a species; allows populations to adapt to changing environments, resist diseases, and maintain overall health
What is species diversity?
Range of different species in a given area; includes number of species (richness) and their relative abundance (evenness)
What is ecosystem diversity?
Variety of ecosystems within a given region, each having its own unique community of organisms and processes
What are the main threats to biodiversity?
- Habitat Loss
- Climate Change
- Pollution
- Invasive Species
- Overexploitation
What defines a species according to the species concept?
Species are groups of interbreeding populations, defined by distinct physical traits and evolutionary history
Who discovered the cell and in what year?
Robert Hooke in 1666
What did Anton Van Leeuwenhoek contribute to cell theory?
First to study magnified cells, naming them animacules in 1674
What is the Cell Theory?
- All known living things are made up of cells
- A cell is the structural and functional unit of all living things
- Cells come from pre-existing cells
What is mitosis?
Most common form of cell division in somatic eukaryotic cells, primarily for growth, repair, and development
What happens during the interphase of mitosis?
Period between two consecutive mitoses; majority of time cells perform regular functions
What occurs during prophase of mitosis?
Nuclear envelope starts to break down, chromatin condenses into chromosomes, and centrosomes duplicate
What is the metaphase stage of mitosis?
Chromosomes align at the metaphase plate, and microtubules attach to each centromere
What happens during anaphase of mitosis?
Identical chromosomes are pulled apart towards opposite poles of the cell
What is cytokinesis?
Last step in mitosis, involves the physical separation of cytoplasm, creating two daughter cells
What is meiosis?
Form of cell division for sexual reproduction, forming sex cells in reproductive organs
What occurs during prophase 1 of meiosis?
- Chromosomes condense
- Homologous chromosomes pair (synapsis)
- Crossing over occurs
What is the end product of Meiosis I?
2 cells with half of the original chromosomes, each with 2 non-identical sister chromatids
What is the final product of meiosis II?
4 haploid cells, each with unique DNA
What is glycolysis?
Process where a glucose molecule is broken down into 2 molecules of pyruvate in the cytoplasm
What is the Krebs Cycle?
Final pathway of oxidation of glucose, fats, and amino acids, occurs in the mitochondrial matrix
What is the electron transport chain?
Final stage of aerobic respiration, located on the inner mitochondrial membrane
What are the two types of transport mechanisms?
- Passive Transport
- Active Transport
What is osmosis?
Diffusion of water across a membrane
What is anabolism?
Building of molecules from simple to complex; requires energy
What is catabolism?
Breaking down of molecules from complex to simple; releases energy
What is epithelial tissue?
Covers all body surfaces, lines body cavities and hollow organs, and is the major tissue in glands
What are the types of epithelial tissue shapes?
- Squamous
- Cuboidal
- Columnar
- Pseudostratified Columnar
What are the main functions of connective tissue?
- Binds structures together
- Supports organs
- Stores fat
- Transports substances
- Protects against diseases
- Helps repair damaged tissue
What is muscular tissue responsible for?
Movement, support, protection, heat generation, and blood circulation
What is nervous tissue responsible for?
Coordinating and controlling body activities such as stimulating contraction and detecting environmental changes
What is the function of the circulatory system?
Supplies oxygen and nutrients, carries wastes and carbon dioxide out, and transports hormones
What is the difference between open and closed circulatory systems?
- Open: Blood pumped into hemocoel
- Closed: Blood pumped through vessels
What is the heart’s primary function?
To pump blood throughout the body
What are the chambers of the heart?
- Atria
- Ventricles
What is the role of valves in the heart?
Separates chambers and prevents backflow of blood
Fill in the blank: The process of ‘cell eating’ is known as _______.
Phagocytosis
Fill in the blank: The process of ‘cell drinking’ is known as _______.
Pinocytosis
What are the upper chambers of the heart called?
Atria (Atrium)
Receives blood coming into the heart and pumps it into ventricles
What are the lower chambers of the heart called?
Ventricles
Pumps blood out of the heart
What is the function of the heart valves?
Separates the chambers of the heart and prevents the backflow of blood
Which valve is located between the right atrium and right ventricle?
Tricuspid Valve
Which valve is located between the left atrium and left ventricle?
Bicuspid (Mitral) Valve
What do pulmonary arteries carry?
Deoxygenated blood to the lungs from the heart
What do pulmonary veins carry?
Oxygenated blood to the heart from the lungs
What is coronary circulation?
Supplies blood to all the cells of the heart
What is the flow of deoxygenated blood through the heart?
Vena Cava - Right atrium - Tricuspid Valve - Right Ventricle - Pulmonary Valve - Pulmonary Artery - Lungs
What is the flow of oxygenated blood through the heart?
Pulmonary vein - Left atrium - Mitral Valve - Left Ventricle - Aortic Valve - Aorta - Body
What is the role of the circulatory system?
Transporting oxygen, nutrients, and wastes throughout the body
What are the components of the human respiratory system?
Trachea, Lung, Bronchi, Bronchioles, Alveoli, Diaphragm, Nasal & Oral cavity, Pharynx, Larynx
What is the function of the diaphragm?
Contracts & flattens to allow chest expansion for breathing
Fill in the blank: The process of gas exchange occurs in the _______.
Alveoli
What is the function of the nervous system?
Controlling, regulating, and communicating in the body
What is the primary function of the brain?
Responsible for responses, sensation, movement, emotions, communication, thought processing & memory
What do sensory neurons do?
Take sensory information from the environment and send it to the brain
What is the role of motor neurons?
Communicate information from the brain to tissues and other organs
What is the function of the spinal cord?
Sends motor commands from the brain to the body and sensory commands from the body to the brain
What is the role of the excretory system?
Remove wastes from the body such as CO2, water, nitrogen, salts, and heat
What are the primary elements that make up living beings?
- Carbon
- Hydrogen
- Nitrogen
- Oxygen
What are the four types of organic biomolecules?
- Carbohydrates
- Lipids
- Proteins
- Nucleic Acids
What is the basic unit of heredity?
Gene
What does DNA stand for?
Deoxyribonucleic Acid
What is the process of copying DNA called?
Replication
Fill in the blank: The observable physical trait of an individual is known as its _______.
Phenotype
What is Mendel’s Law of Segregation?
Each organism carries two alleles for each trait, which segregate during gamete formation
What is the difference between dominant and recessive alleles?
- Dominant: Expressed
- Recessive: Only expressed in absence of dominant
What is a mutation?
Changes in DNA sequence that can lead to alterations in proteins
What are microorganisms?
An organism that is microscopic, can be bacteria, fungi, archaea, protists, algae, or viruses
What is the classification of bacteria by shape?
- Cocci: Spherical
- Bacilli: Rod-shaped
- Spirochetes: Spiral-shaped
What is the difference between gram-positive and gram-negative bacteria?
- Gram-Positive: Show blue or purple, have thick cell walls
- Gram-Negative: Show pink or red, have thin cell walls
What are cylindrical or rodlike bacteria called?
Bacteria
Cylindrical or rodlike bacteria are commonly referred to as bacilli.
What shape do spirochetes have?
Spiral-shaped
Some spirochetes are serious pathogens for humans, causing diseases such as syphilis and Lyme disease.
What are bacteria that need oxygen called?
Aerobes
Aerobes require oxygen for their metabolic processes.
What are bacteria that do not need oxygen called?
Anaerobes
Anaerobes can grow in environments devoid of oxygen.
What color do Gram-positive bacteria show after gram-staining?
Blue or purple
Gram-positive bacteria have thick cell walls that retain the dye.
What color do Gram-negative bacteria show after gram-staining?
Pink or red
Gram-negative bacteria have thinner cell walls and do not retain the dye.
What is the function of the cell wall in bacteria?
Provides structural support and protection
The cell wall is composed of a peptidoglycan mesh-like structure.
What are pili?
Small hairlike projections
Pili assist in attaching to other cells and surfaces.
What is the role of ribosomes in bacteria?
Translates genetic code to amino acids
Bacterial ribosomes are smaller than those of eukaryotes.
What is the function of the capsule in bacteria?
Keeps the bacterium from drying out and protects it from phagocytosis
The capsule is made of polysaccharides.
What is the cytoplasm in bacteria responsible for?
Cell growth, metabolism, and replication
The cytoplasm contains no membrane-enclosed nucleus.
What is the nucleoid?
Region of cytoplasm where chromosomal DNA is located
The nucleoid does not have a membrane-bound nucleus.
What occurs during the lag phase of bacterial growth?
Bacteria adjust to environment and metabolize
This phase may be very short if nutrients are abundant.
What characterizes the log or exponential phase of bacterial growth?
Rapid bacterial multiplication
This phase includes binary fission, where one bacterium splits into two.
What happens during the stationary phase of bacterial growth?
Bacterial growth dwindles due to waste accumulation
If transferred to a new culture, rapid growth may resume.
What is the death phase in bacterial growth?
Bacteria lose ability to reproduce
This phase can occur quickly after growth ceases.
What temperature conditions do bacteria thrive in?
Extreme heat or cold
Bacteria have varied temperature preferences for growth.
What are acidophiles?
Bacteria that grow best at pH values near 3
They thrive in acidic environments.
What are alkaliphiles?
Bacteria that grow best at pH values above 9
They thrive in alkaline environments.
What are viruses classified based on?
Size and shape, chemical composition, structure of the genome, and mode of replication
This classification helps in understanding their behavior and treatment.
What is a capsid?
Protein shell surrounding viral nucleic acid
Some viruses also have an outer envelope composed of lipids and proteins.
What is the first step in the life cycle of a virus?
Viral entry
This involves recognition of viral receptors by a virus particle.
What is the role of attachment factors in viral entry?
Facilitates interaction between virus particles and entry receptors
They help hold virus particles to the cell surface.
What are the two methods of penetration for enveloped viruses?
- Direct fusion
- Receptor-mediated endocytosis
These methods allow the virus to enter the cytoplasm.
What is uncoating in the viral life cycle?
Viral genome exposure to cellular machinery
This occurs during the virus’s approach to the replication site.
What is the exit process for viruses?
Capsid assembly, release, maturation
Viral particles are released via cell lysis.
What is symbiosis?
Close and long-term biological interaction of different species
It can encompass mutualism, commensalism, and parasitism.
What is mutualism?
Relationship where both species benefit
This type of symbiosis enhances survival for both organisms.
What is parasitism?
Relationship wherein one benefits at the expense of the other
This often leads to harm for the host organism.
What is the role of microorganisms in biogeochemical cycles?
Contributes to ecosystem sustainability
They play key roles in nutrient cycling.
What is asepsis?
Methods to prevent contamination by pathogens
Aseptic techniques are crucial in medical and laboratory settings.
What is the purpose of culturing microorganisms?
Growing microorganisms in controlled conditions
This is essential for studying their properties and behaviors.
What does immunology study?
The immune system’s protection against pathogens
It encompasses various aspects of immune responses.
What is immunity?
The body’s ability to recognize and eliminate foreign substances
Immunity can be innate or acquired.
What are the three lines of defense in host defense mechanisms?
- 1st Line: Skin & Mucous membranes
- 2nd Line: White blood cells and inflammatory response
- 3rd Line: Active immune response
These lines provide varying levels of defense against pathogens.
What is the first line of defense in the immune system?
Skin & mucous membranes
These act as physical barriers against pathogens.
What is the function of phagocytes?
Engulf foreign materials
Macrophages and neutrophils are the most important phagocytes.
What is fever in the context of immune response?
Raising body temperature to slow down pathogens
It is induced by pyrogens and plays a role in the immune response.
What are interferons?
Proteins that protect against viral infections
They are secreted by infected cells to warn neighboring cells.
What does the complement system do?
Enhances the immune response
It comprises approximately 30 proteins that participate in immune functions.
What are the three types of T-Cells?
- Helper T-Cells
- Cytotoxic T-Cells
- Memory T-Cells
Each type has distinct roles in the immune response.
What are antigens?
Foreign organic substances that stimulate antibody production
Antigens can be found on the surface of bacteria and viruses.
What are antibodies?
Proteins called immunoglobulins that participate in immune reactions
They help neutralize foreign substances.
What is humoral immunity?
Involves the production of antibodies to recognize and destroy microbes
It is also known as antibody-mediated immunity.
What is cell-mediated immunity?
Involves T-Cells attacking infected cells directly
It does not involve antibodies.
What is immunological memory?
Persistence of memory B and T cells for faster response to pathogens
This allows for a more effective immune response upon re-exposure.
What is natural acquired immunity?
Immunity gained through exposure to pathogens
This occurs naturally when the body encounters a pathogen.
What is artificial acquired immunity?
Immunity acquired through vaccination or antibody transfer
This is a deliberate method to enhance immune protection.
What are vaccines?
Materials that can artificially induce immunity to an infectious disease
They stimulate the immune system without causing the disease.
What are the properties of an ideal vaccine?
- Contains sufficient antigenic determinants
- Minimal side effects
- Does not cause disease
These properties ensure effective and safe vaccination.
What are monoclonal antibodies?
Identical antibodies produced from a single clone of B cells
They are used in diagnostics and therapies.
What is genetic engineering?
Manipulates DNA for various applications
It includes the production of monoclonal antibodies.
What can happen during organ transplants regarding the immune system?
Rejection of foreign tissue
Immunosuppressive drugs are often used to reduce this risk.
