Classification of Living Things
This group of organisms absorbs nutrients from decaying materials instead of making its own food.
Fungi
This female reproductive organ produces egg cells.
Ovaries
These tiny air sacs in the lungs are the main sites of gas exchange.
Alveoli
This organ produces bile, which helps with the digestion of fats.
Liver
This respiratory disease causes inflamed and narrowed airways that may lead to wheezing and shortness of breath.
Asthma
An animal that has a backbone.
Vertebrates
This is the usual site of fertilization in the female reproductive system.
Fallopian Tube
This muscle contracts and moves downward during inhalation, helping expand the chest cavity
Diaphragm
This digestive process allows nutrients from digested food to enter the blood.
Absorption
This reproductive hormone is produced by the testes and plays an important role in male puberty.
Testosterone
A plant near a window gradually bends toward the sunlight. This shows that the plant can do this.
Response to its environment
This male reproductive structure stores sperm while they mature.
Epididymis
After running several laps, a student begins breathing faster. Explain why the body needs to increase its breathing rate.
Active muscles need more oxygen and produce more carbon dioxide that must be removed.
This organ absorbs much of the remaining water and helps form solid waste.
Large Intestine
A student inhales dusty air. What two protective features of the nasal cavity help trap particles before they travel deeper into the respiratory system?
Mucus and cilia
A mushroom grows on a fallen tree and absorbs nutrients from the decaying wood. Explain why it is classified as a fungus rather than a plant.
Because it absorbs nutrients from decaying matter instead of producing its own food through photosynthesis
A fertilized egg reaches the uterus. What must happen for pregnancy to become established?
The fertilized egg must implant in the uterine lining.
A student has damaged alveoli due to emphysema. Which important respiratory process will become less efficient?
The exchange of oxygen and carbon dioxide between the lungs and blood.
A student eats enough food but has a condition that prevents the small intestine from absorbing nutrients properly. Explain how this could affect the student's body.
The body may not receive enough nutrients for energy, growth, and tissue repair.
In a pond, algae are eaten by small aquatic animals, which are then eaten by larger fish. Predict what could happen to the small aquatic animals and larger fish if the algae population suddenly decreases.
Small aquatic animals may have less food, causing their population to decrease and leaving less food available for larger fish.
Scientists discover two organisms that look very different but have similar DNA. Explain why scientists should examine their DNA instead of classifying them based only on appearance.
DNA can reveal evolutionary relationships that physical appearance alone may not show
During the menstrual cycle, the uterine lining thickens in preparation for pregnancy. If pregnancy does not occur, what happens to this lining, and what is the process called?
The uterine lining is shed during menstruation.
Trace the path of air from the nose until it reaches the alveoli. Name the major respiratory structures in the correct order.
Nasal cavity → pharynx → larynx → trachea → bronchi → bronchioles → alveoli.
A piece of bread is chewed in the mouth and later broken down further in the digestive tract. Explain how mechanical and chemical digestion work together.
Mechanical digestion physically breaks food into smaller pieces, while chemical digestion uses substances such as enzymes to break food down into simpler substances.
A student runs a race. Explain how the respiratory and circulatory systems work together to supply the muscles with oxygen and remove carbon dioxide.
The respiratory system brings oxygen into the lungs, where it enters the blood through the alveoli. The circulatory system transports oxygen to the muscles and carries carbon dioxide back to the lungs for removal.