Biology Quiz

• Study notes on key concepts in organismal biology: nutrition, digestion, reproduction, transport, respiration, excretion, nervous system, endocrine system, homeostasis, and plant hormones

Nutrition in Organisms

• Autotrophs produce their own food
• Photosynthetic nutrition is used by plants, algae, and certain bacteria use sunlight to prepare food via photosynthesis
• Green plants are photosynthetic
• Chemosynthetic nutrition is when some bacteria obtain energy by oxidizing inorganic substances like ammonia, sulfur, or iron
• Nitrifying bacteria practice chemosynthesis
• Heterotrophs depend on others for food
• Parasitic organisms live on or inside other living organisms
• Saprophytic organisms derive nutrition from dead organisms
• Holozoic organisms ingest food through mechanical and chemical breakdown

The Human Digestive System

• Digestion begins in the mouth, forming a bolus
• The esophagus moves food via peristalsis
• The stomach breaks down food with gastric juices
• The small intestine is responsible for nutrient absorption
• The large intestine absorbs water and forms waste
• Waste excretion occurs through the anus
• A bolus consists of a ball-like mixture of food and saliva that forms in the mouth during chewing
• Peristalsis involves wave-like muscle contractions that move food through the digestive tract

Reproduction

• Asexual reproduction involves a single parent producing identical offspring
• Binary fission example: Bacteria
• Budding example: Hydra
• Regeneration example: Starfish
• Vegetative propagation example: Plants
• Monoecious plants feature both male and female flowers on the same plant i.e. unisexual flowers
• "Mono-" means one, and "-oecious" refers to house
• Maize and coconut are monoecious plants
• Dioecious plants have male and female flowers on separate plants
• "Di-" means two, and "-oecious" refers to house
• Papaya and date palm are dioecious plants
• Sexual reproduction entails:
• In the male reproductive system, the testis, specifically the seminiferous tubules, produces sperm
• The epididymis matures sperm
• Sperm travels through the vas deferens, then the urethra, and finally the penis
• Sperm cells combine with seminal fluid to form semen
• In the female reproductive system, the ovary produces egg cells
• Fertilization occurs in the fallopian tube
• A fertilized egg implants and grows in the uterus (womb)
• Ectopic pregnancy refers to fertilized egg development outside the uterus, such as in the Fallopian tube

Transport Systems

• Plants have:
• Xylem conducts water and nutrients upward from roots through transpiration
• Phloem conducts sugars and nutrients downward from leaves through translocation
• Humans have a circulatory system with different types of blood vessels:
• Pulmonary arteries carry deoxygenated blood from the heart to the lungs
• Pulmonary veins transport oxygenated blood from the lungs to the heart
• Systemic arteries carry oxygenated blood to the body
• Systemic veins transport deoxygenated blood to the heart
• Capillaries facilitate gas exchange

Respiratory System

• Air travels: nose to pharynx to larynx to trachea to bronchi to bronchioles to alveoli, where CO2 and O2 exchange occurs
• The epiglottis prevents food from entering the trachea

Excretory System

• The path: kidney to ureter to urinary bladder to urethra
• The kidney's key functions include:
• Filtration of water and solutes
• Excretion of waste products such as creatinine
• Reabsorption of 100% of glucose and water

Nervous System

• The nervous system's primary function is to control and coordinate body functions and responses
• Brain parts, and their functions:
• The cerebrum handles voluntary/conscious activities
• The cerebellum coordinates movement and balance
• The brainstem connects the brain to the spinal cord
• Spinal cord:
• The spinal cord serves as the main communication link between the brain and body
• Reflexes are examples of quick, automatic responses to stimuli
• Sneezing and blinking are reflexes
• Neuron types paired with function:
• Unipolar (sensory) receives stimuli
• Multipolar (motor) controls muscle movement
• Bipolar (interneuron) bridges sensory and motor neurons
• The Peripheral Nervous System (PNS) splits:
• The Somatic Nervous System controls voluntary activities i.e. skeletal muscles
• The Autonomic Nervous System controls involuntary activities i.e. heart rate
• The Autonomic Nervous System subdivisions are:
• The Sympathetic Nervous System instigates "fight or flight" responses, increasing alertness, energy, and heart rate
• The Parasympathetic Nervous System enacts "rest and digest", returning the body to a calm state

Endocrine System

• Hormones are chemical messengers that regulate body functions
• Ovaries produce estrogen, stimulating the uterine lining and female traits
• Testes produce androgen, supporting sperm formation and male traits
• The pancreas produces insulin, which lowers blood sugar
• The pancreas produces glucagon, which raises blood sugar
• The pituitary produces vasopressin, responsible for water retention in kidneys

Homeostasis

• Homeostasis is the tendency of a system to resist change and maintain a stable environment as exemplified by:
• Temperature regulation through sweating and shivering
• Osmotic balance via water regulation in kidneys
• Glucose levels balanced by insulin and glucagon control blood sugar

Regulation of Life Processes in Plants (Phytohormones)

• Auxin stimulates stem cell elongation
• Gibberellin stimulates stem elongation and seed germination
• Cytokinin stimulates cell division and delays aging
• Abscisic Acid inhibits growth and closes stomata
• Ethylene stimulates fruit ripening

Test your knowledge of key biological concepts with these multiple-choice questions. Topics include nutrition, plant reproduction, human digestion, and the circulatory system. Evaluate your understanding of fundamental life processes.