Characteristics of Life
Which observation provides the strongest evidence that an object is nonliving?
A. It increases in size
B. It cannot perform metabolic processes
C. It responds to changes in temperature
D. It contains organic molecules
B. It cannot perform metabolic processes
Which organelle is the site of photosynthesis?
A.Mitochondrion
B.Ribosome
C.Chloroplast
D.Lysosome
Which class of biological molecules speeds up chemical reactions?
A.Lipids
B.Proteins
C.Carbohydrates
D.Nucleic acids
B.Proteins
Which term describes maintaining relatively stable internal conditions?
A.Synthesis
B.Homeostasis
C.Reproduction
D.Digestion
B.Homeostasis
Which compound is inorganic?
A.Glucose
B.Carbon Dioxide
C.Protein
D.Starch
B.Carbon Dioxide
Which life activity involves obtaining and processing materials needed for survival?
A. Respiration
B. Excretion
C. Nutrition
D. Reproduction
C. Nutrition
Which organelle is primarily responsible for releasing usable energy from nutrients during cellular respiration?
A.Nucleus
B.Mitochondrion
C.Vacuole
D.Golgi apparatus
B.Mitochondrion
The function of an enzyme is most directly influenced by its:
A.Color
B.Mass
C.Physical shape
D.Location in the body
C.Physical shape
After a carbohydrate-rich meal, blood glucose rises. Which hormone helps return it toward normal?
A.Glucagon
B.Adrenaline
C.Insulin
D.Melatonin
C.Insulin
Which practice is safest when heating a solution in a test tube?
A.Seal the test tube with a stopper.
B.Point the opening toward a partner.
C.Wear safety goggles.
D.Hold the test tube with bare fingers.
C.Wear safety goggles.
Which life process is NOT necessary for the survival of an organism?
A. Respiration B. Nutrition C. Synthesis. D. Reproduction
D. Reproduction
Which structures are found in every living cell?
A.Cell wall and nucleus
B.Chloroplasts and mitochondria
C.Plasma membrane and cytoplasm
D.Nucleus and vacuole
C.Plasma membrane and cytoplasm
Salivary amylase acts on starch but not protein. This demonstrates that enzymes:
A.Are chemically specific
B.Are used up in reactions
C.Function at all temperatures
D.Contain starch molecules
A.Are chemically specific
Which situation best illustrates an organism maintaining homeostasis?
A.A snake enters a cool burrow on a hot day.
B.A shark swims into polluted water.
C.A plant root grows away from moisture.
D.A polar bear loses fur during winter.
A.A snake enters a cool burrow on a hot day.
A scientist identifies a structure made of a group of similar cells performing a common function. Name this level of organization and explain how it differs from an organ.
It is a tissue. A tissue is a group of similar cells with a common function, while an organ contains multiple tissue types working together.
Arrange from smallest to complex:
organ, cell, organism, organelle, organ system, tissue
A muscle cell contains significantly more mitochondria than another type of cell. State ONE inference about the muscle cell and explain your reasoning.
The muscle cell has a high energy demand because mitochondria release usable energy through cellular respiration.
A person develops a fever of 105°F. Explain how this unusually high temperature could affect enzyme activity.
High temperatures may alter enzyme shape, including its active site, causing activity to decrease or stop. This is called denaturation.
Explain how remaining in the shade or underground during hot daylight hours helps a desert lizard maintain homeostasis.
The behavior reduces exposure to environmental heat, helping prevent excessive increases in body temperature.
Which of the following statements best describes the relationship between organelles in a cell?
A) Each organelle functions independently of the others.
B) All organelles perform the same function.
C) Organelles work together to carry out cellular activities.
D) Organelles function only when homeostasis is disrupted.
C) Organelles work together to carry out cellular activities.
An icicle grows larger over time. Explain why this does not make the icicle a living organism. Include two characteristics of living organisms in your explanation
An icicle may increase in size, but it does not perform metabolism or maintain homeostasis through cellular processes. It is not made of living cells
Explain how TWO different organelles work together to help a cell function. Identify each organelle and describe its role.
Example: The nucleus contains genetic instructions for proteins, and ribosomes use those instructions to synthesize proteins. Their coordinated activities support cell functions.
Explain another factor that could impact enzyme activity in full
Changing the pH (from acid to base) could alter the shape and function
Provide an example of POSITIVE AND NEGATIVE feedback. A DETAILED EXPLANATION!
Positive- Childbirth- the body releases oxytocin until the baby is completely delivered - Intensifies the stimulus.
Negative Feedback- brings the body back to normal- sweating when hot.
A student is conducting an experiment involving enzymes. The student accidentally places an enzyme solution in boiling water for several minutes. Afterward, the enzyme no longer speeds up its usual chemical reaction.
Another student suggests adding more substrate to make the enzyme work again.
Using your knowledge of enzymes, explain why adding more substrate would likely NOT restore the enzyme's activity.
Boiling water can cause the enzyme to denature, changing the shape of its active site. Because the substrate can no longer fit properly into the active site, adding more substrate will not restore the enzyme's original shape or function.