Abeka Biology chapter 22
Briefly describe the overall structure of the nucleus. What purpose does the nucleus serve?
*The nucleus is a spherical body often located near the center of the cell; it is separated from the rest of the cell by a double membrane (the nuclear envelope). Within the nucleus is a distinct region called the nucleolus. *The main purpose of the nucleus is to store and maintain the cell's DNA "blueprints" and to retrieve information from the DNA as the cell needs it.
Describe mitosis in detail beginning with the preparations during interphase.
*interphase - During the S phase, the chromosomes are replicated to produce two attached copies of each chromosome, each copy is a chromatid. In human and animal cells, the centrosomes also replicate. *prophase - The cell packages the chromosomes into tightly packed structures that are visible through a microscope. The nucleolus is dismantled, and the centrosomes move to the poles of the cell and begin to form the spindle apparatus. At the end of prophase, the cell dismantles the nuclear membrane. *metaphase - The spindle apparatus attaches to the centromere of each replicated chromosome and pulls the chromosomes until they are aligned along the equatorial plane of the cell. *anaphase - The chromatids in each replicated chromosome separate from each other and begin to move apart. The spindle apparatus drags the chromatids toward opposite ends of the cell. (Usually, cytokinesis also begins during this stage.) *telophase - The nuclear membrane reforms in each daughter cell; DNA is uncoiled; and a nucleolus forms in each daughter cell. (Usually, cytokinesis is completed during or just after this stage.)
What are some processes that a cell must carry out continually in order to maintain life?
Answers should include some of the following ideas: *taking in food to power its systems and ridding itself of waste products *pumping ions in and out to balance its osmotic pressure and its pH *replacing or refurbishing worn-out machinery
How does cellular respiration allow a cell to produce ATP?
In cellular respiration, chemical substances such as glucose are broken down to release energy. This energy is used to synthesize ATP.
Identify Three scientists whose work led to the formulation of the cell theory
Robert Hooke, Matthias Schleiden, Theodore Schwann
What is the purpose of rough and smooth endoplasmic reticulum.
Rough endoplasmic reticulum processes proteins; smooth endoplasmic reticulum produces fat and breaks down toxins and wastes.
How do the Golgi apparatus and the cytoskeleton work together to transport proteins from one region of the cell to the other?
The Golgi apparatus receives proteins from thr endoplasmic reticulum, packages them, and ships them to their final destinations. The cytoskeleton and asociated motor proteins haul the protein-containing vesicles to their destinations.
Identify three main parts of every living cell
cell membrane, cytoplasm, nucleus
Identify the large protein molecules that carry out the chemical activities of the cell.
enzymes
Identify four main chemical elements of the cell
oxygen, carbon, hydrogen, nitrogen
