What can be caused by direct or passive inhalation?
Options:
- (A) skin grafts
- (B) prolonged thirst
- (C) science
- (D) Toxicity
- (E) lung cancer
- (F) negative
- (G) friction
- (H) craters
--
Let's think first: Lung cancer is most often caused by exposure to tobacco smoke. Smoke Tobacco smoke , whether directly or passively inhaled, has been shown to worsen asthma. Lung cancer can be caused by direct or passive inhalation.... So the answer is [(E)]

What are single celled organisms that do not have a nucleus?
Options:
- (A) Most plants
- (B) nucleus
- (C) ferns
- (D) fossil fuels
- (E) bushes
- (F) Eukaryotes
- (G) leech
- (H) bacteria
--
Let's think first: Prokaryotes are single-celled organisms that lack a nucleus. Prokaryotes are usually microscopic and bacteria is an example of a prokaryote. Bacteria are single celled organisms that do not have a nucleus.... So the answer is [(H)]

What have varied life cycles?
Options:
- (A) bacteria
- (B) fungi
- (C) Variety.
- (D) Cycles.
- (E) plants
- (F) Plants.
- (G) insects
- (H) Life of air.
--
Let's think first: Algae have varied life cycles. Some, such as the green algae, are plants. Some plants have varied life cycles.... So the answer is [(F)]

Flukes, tapeworms, and turbell are
Options:
- (A) major threat to health
- (B) types of flat leeches
- (C) Plant growth is reduced
- (D) types of earthworms
- (E) competing for resources
- (F) types of snakes
- (G) types of flatworms
- (H) parasites
--
Let's think first: Flatworms belong to the phylum Platyhelminthes. Flatworms Flatworms or Platyhelminthes include flukes, tapeworms, and turbellarians. Types of flatworms are flukes, tapeworms, and turbellarians.... So the answer is [(G)]

What do many plants do to respond to the shorter days in fall?
Options:
- (A) go through a resting period
- (B) changing the phase
- (C) Release energy
- (D) Generating heat
- (E) produce more pollen
- (F) colder and wetter
- (G) grow taller
- (H) make more chlorophyll
--
Let's think first: Many plants respond to the days growing shorter in the fall by going dormant. Plants can be divided at any time, although the dormant or rest period is best. Many plants respond to the days growing shorter in the fall by going through a rest period.... So the answer is [(A)]

What happens as cells lose their ability to divide?
Options:
- (A) anemia
- (B) puberty
- (C) negative
- (D) radiation
- (E) getting old
- (F) replication
- (G) Dehydration
- (H) having a baby
--
Let's think first: Aging occurs as cells lose their ability to divide. Gerontology is the study of the aging process and old age. Getting old occurs as cells lose their ability to divide.... So the answer is [(E)]