1
Why do some species employ both mitosis and meiosis, whereas other species use only mitosis?
- They need meiosis if the cells are producing organs such as ovaries.
- They need only meiosis if they produce egg cells.
- They need both if they are producing plant gametes.
- They need only mitosis to make large numbers of cells such as sperm.
They need both if they are producing plant gametes.
Ex.
The production of gametes in plants is a function of both mitosis and meiosis. The form of cell division that produces animal gametes is meiosis, not mitosis.
2
A human bone marrow cell, in prophase of mitosis, contains 46 chromosomes.
- True
- False
True
3
Which of the following is true of kinetochores?
- They are sites at which microtubules attach to chromosomes.
- They are located at the center of the centrosome; their function is to organize tubulin into elongated bundles called spindle fibers.
- They attach to the ring of actin along the cytoplasmic surface of the plasma membrane, causing the actin to contract to form the cleavage furrow.
- They are the primary centromere structures that maintain the attachment of the sister chromatids prior to mitosis.
They are sites at which microtubules attach to chromosomes.
4
G1 follows cell division.
- True
- False
True
5
In some organisms, such as certain fungi and algae, cells undergo the cell cycle repeatedly without subsequently undergoing cytokinesis. What would result from this?
- a decrease in chromosome number
- division of the organism into many cells, most lacking nuclei
- a rapid rate of gamete production
- large cells containing many nuclei
large cells containing many nuclei