Chapter 2 Flashcards
What is the basic unit of life?
The cell
What is cell division in prokaryotes?
A process called Binary Fission, DNA Replication, growth, new plasma membrane and cell wall, 2 new genetically identical cells.
What are Prokaryotes?
-Unicellular, no membrane-bound organelles.
-Prokaryotic DNA doesn’t exist in the highly ordered and packed arrangement, chromosome is circular.
-Made up of bacteria and archaea
- Divide rapidly through binary fission.
What are Eukaryotes?
- Both unicellular and
multicellular with
membrane-bound
organelles - Genetic material is
surrounded in a nuclear
envelope to form a nucleus - Linear DNA is closely
associated with histones to
form tightly packed
chromosomes - Have more DNA
- Multiple linear chromosomes
- More complex division (meiosis/mitosis)
What are viruses?
Neither prokaryotic nor eukaryotic. Outer protein coat
surrounding nucleic acid
(DNA or RNA). Obligate intracellular parasites.
What is a diploid cell?
Cells that carry two sets of genetic information on
homologous pairs of chromosomes.
What is a haploid cell?
Cells that carry one set of genetic information.
What are polyploid cells?
Cells that carry more than two sets of genetic
information.
How many chromosome pairs do humans have?
23 pairs.
What is a Gene?
Represents a region of DNA on a chromosome that codes for something (like hair and eye color).
What is an Allele
Represents a version of that gene (like brown or blue eye color)
What is a Homologous chromosome?
Have the same genes, but may have different alleles.
What is a Sister Chromatid?
Should be genetically identical to each other. Occurs when the DNA has replicated, and the cell is getting ready to divide
What is a histone?
A protein that provides structural support for a chromosome (helps form tightly packed chromosomes)
What are the three parts of a eukaryotic chromosome?
- The Centromere- attachment point for spindle microtubules (kinetocore: protein complex for attachment to spindle fibers at
centromere). - The Telomere- tips of a linear chromosome.
- Origins of Replication-
not easily observed, but needed for
DNA synthesis to begin.
*Sister chromatids also important