Flashcards in Cytological Basis of Inheritance Deck (14)
The ultimate units of inheritance
2 types of chromosomes
A constricted region of a chromosome where it separates the short and the long arm
What is mitosis?
A means of reproduction in lower forms of organisms and promotes growth and repair in multicellular organisms
One cell becomes two diploid, genetically identical cells
A period of growth and rest; non-dividing phase
Mitosis: The nucleus, cytoplasm, and organelles grow
Mitosis: DNA and histone proteins are synthesized
Mitosis: RNA and proteins are synthesized
What does the kinetochore do?
Joins the spindle fiber and the chromosomes and pulls them toward opposite poles
What are chromatins, chromosomes, and chromatids?
Chromatin - DNA and histone proteins
Chromosome - Tightly-packed chromatin with a centromere
Chromatid - Two joined chromosomes
What happens after meiosis?
The number of chromosomes is reduced by half.
One cell becomes four haploid, genetically unique cells
What are the phases of Prophase I?
Leptotene - Chromosomes are tender and long with many beadlike structure along their length
Zygotene - Chromosomes continue to shorten and thicken, pairing or synapsis of homologous chromosomes begins
Pachytene - Coiling and shortening of the chromosome continues, the pair chromosomes form a bivalent
Diplotene - Longitudinal separation of bivalents occurs, also known as crossing over
Diakinesis - Bivalents assume maximal contraction, nucleolus disappears, spindle fibers form
What is another term for a bivalent?