Chapter 12 Flashcards
Do cells spontaneously appear, or do they arise through preexisting cells?
Preexisting cells
What is cell division that results in asexual reproduction in bacteria called?
binary fission
What is the circular DNA in prokaryotes called specifically?
Nucleoid
What are the two types of cell division found in eukaryotes? Explain both.
1) Meiosis- produces genetically different gametes (eggs and sperm) that are haploids
2) Mitosis- produces all other cell types referred to as somatic cells
What is mitosis (and cytokinesis) significant for? (Hint: There are 3 major functions.)
Growth, Replace damaged cells, Asexual reproduction.
How is DNA packaged in chromosomes?
DNA wraps around his tone proteins and packaged as chromosomes.
Define chromatid.
Each of the DNA copies in a replicated chromosome
Define sister chromatids.
Chromatids from the same chromosome
What is the structure where sister chromatids join together called?
Centromere
How many chromosomes are there when there are 2 sister chromatids? (Hint: Chromosome looks like an X in shape.)
1 chromosome 46
Define chromatin.
The material that makes up eukaryotic chromosomes, consists of a DNA molecule complexed with his tone proteins
Define kinetochore.
The structures on sister chromatids where microtubules attach
What is the microtubule-organizing center called?
Centrosome
What are the cylindrical structures that make microtubules called?
Centioles
What are the two phases of the cell cycle? Explain both.
Explain what occurs during the G1 phase.
Explain what occurs during the S phase.
Explain what occurs during the G2 phase.
Name the phase that nondividing cells stay in. Give an example of a cell type that is in this stage.
What criteria must the cell meet to pass the G1 checkpoint?
What criteria must the cell meet to pass the G2 checkpoint?
What criteria must the cell meet to pass the M-phase checkpoints?
What induces mitosis in all eukaryotes? (Hint: It is found in the cytoplasm of eukaryotic cells.)
What are the two subunits that comprise MPF? Explain both.
Does Cdk’s concentration change? Does cyclin’s concentration change?
When is Cdk considered active?
If Cdk has ONE phosphate attached it is: active/inactive? If Cdk has TWO phosphates attached it is :active/inactive?
Once MPF is activated, mitosis is triggered by? (Hint: There are 2 points to the answer.)
List the five sub phases in mitosis, in order.
Summarize what occurs in prophase.
What are microtubules composed of?
What is the function of microtubules?
What happens to the nuclear envelope during prometaphase?
What do the microtubules do during prometaphase? Where do they attach specifically?
Summarize what occurs in metaphase.
The imaginary plane formed by metaphase is called the _________ ?
How is it that the sister chromatids separate in anaphase?
Where does depolymerization occur? The + or - end of the kinetochore microtubule?
Summarize the events of telophase.
Define cytokinesis.
What creates the cell plate found in plants?
What are the filaments called that cause a pinch in the cell membrane? What is this pinch called? (Hint: This “pinch” occurs in animals.)
What is the tumor suppressor protein? And what does it do?
Uncontrollable division of one or more cells in a multicellular organism leads to ______?
What are the two types of defects that cancerous cells can have?
Compare the difference between benign tumors and malignant tumors.
What occurs during metastasis?
