Questions and Answers
What are the three domains of life?
Who proposed the naming system that includes the three domains of life?
Which of the following statements about archaea and bacteria is true?
What is the role of parathyroid hormone in calcium regulation?
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Which characteristic is shared by both archaea and bacteria?
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Which type of bone marrow is responsible for producing blood cells?
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What is the function of the compact bone?
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In the biological taxonomic system, which level comes after 'Phylum'?
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What compound characterizes the cell walls of archaea?
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How are bones categorized based on their shape?
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What are the main functions of the axial skeleton?
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What does LUCA stand for in the context of biological classification?
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What is the first step in using a dichotomous key?
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Which of the following is NOT one of the levels of structural organization in the human body?
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What characteristic is unique to eukaryotes compared to Archaea?
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What type of tissue primarily covers and protects the body?
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Which type of bacteria is shaped like a spiral?
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Which of the following is NOT a type of extremophile found in Archaea?
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Which organ system is responsible for distributing oxygen and nutrients throughout the body?
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What is the main function of Methanobrevibacter smithii in the human gut?
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What is the basic unit of life in the organization of living matter?
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Which organ is primarily part of the nervous system?
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Which statement about the three domains of life is true?
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What key feature distinguishes bacteria cell walls from those of archaea?
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Which type of connective tissue is primarily responsible for cushioning the body?
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The taxonomic classification from broadest to most specific includes which of the following first?
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What is the function of muscle tissue?
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Which level of organization is the highest in the human body?
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Which kingdom includes multicellular, autotrophic organisms?
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What characteristic do all members of the domain Archaea share?
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What role does the cardiovascular system play in cellular function?
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What organelle in eukaryotic cells is responsible for enclosing DNA?
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Which molecule is NOT one of the four main macromolecules that make up cellular structure?
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What type of cells have a high number of mitochondria to support their energy needs?
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How many bones are there in the adult human skeleton?
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What is one function that bones do NOT perform?
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Which part of the integumentary system serves to regulate temperature?
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What function do tendons serve in relation to the bones?
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What component of the skeleton protects the spinal cord?
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Which glands are part of the exocrine glands in the integumentary system?
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What type of cell is primarily responsible for detoxifying the body in the liver?
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Study Notes
Biological Classification
- Biological taxonomy involves naming and classifying organisms based on characteristics.
- The system consists of eight hierarchical groups from broad to specific: Domains, Kingdoms, Phylum, Class, Order, Family, Genus, and Species.
Three Domains of Life
- The three domains are Archaea, Eukarya, and Bacteria, proposed by Carl Woese in 1977.
- Woese discovered archaea as a distinct group separate from bacteria, accepting it as a domain in 1990.
- Key differences between archaea and bacteria include:
- Ribosomal RNA sequences, where archaea differ.
- Enzyme composition: Archaea have three RNA polymerases; bacteria have one.
- Cell wall structure: Archaea use pseudopeptidoglycan; bacteria use peptidoglycan or lipopolysaccharide.
- Archaea are more closely related to eukaryotes than to bacteria.
Characteristics of the Domains
- Eukarya: Multi-cellular organisms with double-helix DNA and nuclei.
- Archaea: Single-celled, with RNA instead of DNA, a-cell wall of pseudopeptidoglycan, no nuclei, and include extremophiles.
- Bacteria: Single-celled organisms with nucleic acid, peptidoglycan cell walls, and vast environmental presence.
Extremophiles in Archaea
- Archaea thrive in extreme conditions, categorized into:
- Halophiles (saline habitats)
- Acidophiles (acidic environments)
- Thermophiles (high temperatures)
- Alkaliphiles (basic habitats)
Alternative Classifications
- Some scientists propose different classifications, such as:
- Ernst Mayr's theory suggesting a two-empire system merging Archaea and Bacteria.
- Thomas Cavalier-Smith's six-kingdom model, including Chromista and Archezoa.
- Radhey S. Gupta's classification based on Gram-negative and Gram-positive distinctions in prokaryotes.
Levels of Organization in the Human Body
- Human body's structural organization begins at atoms and progresses to cells, tissues, organs, organ systems, and finally, the organism.
- Key elements in living organisms include Carbon, Hydrogen, Nitrogen, Oxygen, Phosphorus, and Sulfur.
Human Body Organization Levels
- Cells (e.g., Cardiomyocyte)
- Tissues (types: Epithelial, Connective, Muscle, Nervous)
- Organs (e.g., Heart, Brain)
- Organ Systems (e.g., Cardiovascular, Nervous, Digestive)
- Organism Level (complete human body)
Organ Systems and Their Functions
- The cardiovascular system transports blood, heat, and nutrients; key organs include the heart and blood vessels.
- The nervous system enables electrochemical communication; key organs include the brain, spinal cord, and nerves.
Functions of Bones in the Human Skeleton
- Bones serve multiple roles: support, protection, movement, storage, and blood cell production.
- Humans possess 206 bones that provide structure and serve as attachment points for muscles.
Bone Functions Overview
- Support: Provides body structure and maintains upright posture.
- Protection: Shields internal organs (e.g., skull for the brain, rib cage for the heart).
- Movement: Work with muscles for physical activity, facilitated by tendons.
- Storage: Stores calcium and phosphorus, essential for bodily functions.
Integumentary System
- Comprises skin, hair, nails, and glands.
- Functions include protection, temperature regulation, and moisture maintenance.
Cellular Level of Organization
- Cells are the fundamental units of life, containing specialized organelles (e.g., mitochondria for energy production).
- Over 200 cell types exist in humans, each coded by DNA in the nucleus.### Calcium's Role in Muscle and Nerve Function
- Calcium is crucial for muscle contractions and nerve impulse transmission.
- Low blood calcium levels trigger the release of parathyroid hormone, promoting bone breakdown for calcium release.
- High blood calcium levels stimulate calcitonin release, which facilitates calcium absorption by bones.
Blood Cell Production
- Red bone marrow is primarily responsible for blood cell production.
- Consists of two types: red (produces blood cells) and yellow (stores fat).
- Decreased blood oxygen levels stimulate increased red blood cell production from red bone marrow.
Bone Structure and Types
- Bones contain living cells and various types of bone tissue: compact and spongy.
- Compact bone is the dense outer layer, containing osteons, osteocytes, canaliculi, and Haversian canals for blood vessel and nerve support.
- Spongy bone, found inside bones, contains trabecular lamellae and houses red bone marrow.
Layers of a Bone
- Bones have distinct layers: periosteum (outer membrane), compact bone, spongy bone, endosteum (inner membrane), and a central medullary cavity.
- Diaphysis refers to the bone's shaft; epiphysis indicates the bone's ends, where growth occurs via the epiphyseal line.
Types of Bones
- Bones are categorized by shape:
- Long bones: longer than wide (e.g., femur)
- Short bones: cube-shaped, equal length and width (e.g., carpals)
- Sesamoid bones: found within tendons (e.g., patella)
- Flat bones: thin and curved (e.g., skull)
- Irregular bones: complex shapes (e.g., vertebrae)
Bone Cells
- Three types of bone cells exist:
- Osteocytes: mature bone cells maintaining bone structure.
- Osteoblasts: cells responsible for bone formation.
- Osteoclasts: large cells that break down bone tissue.
The Skeleton's Structure
- Human skeleton comprises 206 bones, categorized into axial and appendicular sections.
Axial Skeleton
- Forms the body's central axis, including the skull, vertebrae, and thoracic cavity.
- Protects brain, spinal cord, and vital organs, facilitating side-to-side movement.
Appendicular Skeleton
- Comprises limbs and girdles (pelvic and pectoral).
- Facilitates movement, supports posture, and aids blood cell production.
Muscular System Overview
- The muscular system is essential for body movement and connects to bones.
- Functions include posture maintenance, blood transport, and heat generation.
- Muscles consist of origins (stationary bone) and insertions (moving bone).
Muscle Classification
- Muscles classified as:
- Agonists: primary movers.
- Antagonists: opposing muscles.
- Synergists: assist primary movements.
Types of Muscle Tissue
- Three muscle tissue types:
- Visceral (smooth): non-striated and involuntary.
- Cardiac: striated and involuntary, found in the heart.
- Skeletal: striated and voluntary, attached to bones.
Motor Units
- Composed of neurons that control muscle movements, affecting various body parts.
Circulatory System Overview
- Composed of the heart, blood, and vessels, functioning in two main circuits:
- Pulmonary circuit: moves deoxygenated blood to lungs for oxygenation.
- Systemic circuit: delivers oxygenated blood to body tissues.
Circulatory Functions
- Delivers oxygen, removes carbon dioxide, transports nutrients, and supports homeostasis.
- Can be affected by conditions like atherosclerosis and high blood pressure, leading to symptoms such as fatigue and muscle cramps.
Respiratory System Overview
- Functions to bring oxygen into the body and expel carbon dioxide.
- Comprises organs like the lungs, trachea, bronchi, and diaphragm.
Respiratory Functions
- Ensures oxygenation of blood and carbon dioxide removal, working alongside the cardiovascular system.
- Breath regulation is controlled by brain responses to blood gas levels.
Respiratory Conditions
- Common conditions include asthma, cystic fibrosis, emphysema, and COPD, affecting airflow and gas exchange.
- Cellular respiration is the reverse of photosynthesis, facilitating energy production.
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Description
Test your knowledge on the biological taxonomy of humans. This quiz covers the hierarchical classification system ranging from domains to species. Discover the eight groups that define the organization of living organisms based on their characteristics.
