Levels of Organization
What are the four main levels of organization in living things?
Cells → Tissues → Organs → Organ Systems
What are the two main tubes in plants that transport water and food?
Xylem and phloem
Which organ filters blood?
Kidneys
Which system gives the body shape and support?
skeletal system
Who is known as the father of genetics?
Gregor Mendel
Which level of organization is the brain?
organ
What gas do humans inhale and what gas do they exhale?
Inhale oxygen, exhale carbon dioxide
What is the main function of the digestive system?
To break down food into nutrients the body can use
What is the main function of the muscular system?
movement
What is a trait?
A characteristic passed from parents to offspring
Give one example of a tissue in the human body.
Muscle tissue or nervous tissue
Explain the main function of the xylem and the phloem.
Xylem transports water and minerals; phloem transports food (sugar)
Describe the correct order of the four main stages of digestion and what happens in each.
Ingestion: taking in food → Digestion: breaking food down → Absorption: nutrients enter the blood → Elimination:removing undigested waste
How do bones and muscles work together to move the body?
Muscles contract and pull on bones acting as levers
What are alleles?
Different forms of a gene
Why do multicellular organisms need levels of organization?
To divide work and perform complex functions efficiently
How does the structure of alveoli in the lungs help in gas exchange?
Alveoli have thin walls and a large surface area surrounded by capillaries, allowing oxygen and carbon dioxide to diffuse efficiently.
Explain how the digestive and excretory systems work together.
Digestive breaks down food → nutrients enter blood → waste removed by excretory system
Give one example of a ball-and-socket joint and one example of a hinge joint.
Shoulder or hip = ball-and-socket; elbow or knee = hinge
What does it mean if an organism is heterozygous for a trait?
It has two different alleles for that gene (e.g., Tt)
Describe how cells in the human body are specialized for different functions.
They have unique structures (e.g., red blood cells carry oxygen, neurons transmit signals)
Compare how materials move in the human body and in plants.
Humans use circulatory and respiratory systems to move oxygen and nutrients through blood; plants use xylem and phloem to move water, minerals, and food.
What would happen if waste materials were not removed from the body?
Toxins would build up and damage organs
What is the difference between voluntary and involuntary muscles?
Voluntary muscles are controlled consciously (like skeletal muscles), while involuntary muscles work automatically (like the heart or stomach)
Explain the difference between genotype and phenotype.
Genotype = genetic makeup; Phenotype = physical appearance