Researchers looking for fossils of the earliest life forms face many hurdles. For example, few sedimentary rocks date back more than 3 billion years. Review what you learned about plate tectonics. Explain why so few remaining samples of these early rocks remain
What will be an ideal response?
Plate tectonics involves the constant movement of geologic plates on the surface of the Earth. These plates collide, and rise over or move under adjoining plates. Where plates are separating, molten material from the core of the Earth makes its way to the surface. Over such long geologic time (many billions of years), the plates have moved dramatically, eliminating the earliest sedimentary rocks from the surface of the Earth.
You might also like to view...
Which of the following is an accurate description of the plasma membrane?
A. One layer of phospholipids with a number of proteins embedded within B. Two layers of proteins with a few phospholipids embedded within C. Two layers of phospholipids with a number of proteins embedded within D. One layer of proteins with a few phospholipids embedded within
Which of the following would be a way of finishing this hypothesis about the function of the Golgi apparatus? If the Golgi apparatus is involved in packaging products for secretion, then
A. the Golgi apparatus would contain proteins. B. the Golgi apparatus must be part of the endomembrane system. C. vesicles must travel from the RER and SER to the Golgi apparatus. D. vesicles must travel from the Golgi to the cell surface. E. the Golgi apparatus must consist of 3 to 20 slightly curved sacs.
Explain the concept of selective toxicity.
What will be an ideal response?
Match the letter of each example from childbirth to the appropriate component of a positive feedback loop.A. Pituitary gland secretes oxytocin, which acts on the uterusB. Uterine contractions increaseC. Fetus is pushed against uterine openingD. Receptors detect stretchE. Brain receives and compares stretch informationStimulus
What will be an ideal response?