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concepts to know for exam 2: ch 9

Terms in this set (11)

Describe the bonds present in RNA and DNA.
- polymers of nucleotides are held together by covalent phosphodiester bonds
- the bases are held together by hydrogen bonds
- hydrogen bonds are much more weak
Explain biological needs for binary fission or mitosis
mitosis is necessary for growth, repair, remodeling, and differentiation
Define stem cell, self-renewal, potency, differentiation.
stem-cell- can divide and self renew and are potent
potency- multiple differentiable cell types
differentiation- a process where a cell becomes specialized in order to preform a specific task
Describe what happens to cause cells to differentiate, and thus organisms to develop
occurs through gene expression*****
Describe binary fission in prokaryotes and Contrast binary fission with mitosis
binary fission occurs in prokaryotic cells while mitosis occurs in eukaryotic cells
5 steps to binary fission:
- the prokaryotic chromosome is attached to the plasma membrane at one point
- the DNA replicates and the resulting two chromosomes attach to the plasma membrane at near by points.
- new plasma membrane is added between the attachment points, pushing the two chromosomes farther apart
- the plasma membrane grows inward at the middle of the cell
- the parent cell divides into two daughter cells
Describe eukaryotic chromosome structure in an uncondensed and condensed state. Describe
the role of histones. Label telomere, centromere, gene, locus, allele
- chromosomes are separated from the cytoplasm by a membrane bound nucleus
- contain multiple linear chromosomes
- 10-50 times more DNA the pro. chromosomes
- the double helix winds around histone proteins making the DNA more condensed
telomere- the end of the chromosome
gene- segment of DNA
locus- the position of a gene on a chromosome
Explain how the terms gene, DNA, chromosome, genome, genotype, allele, and mutation fit
together
- they all have to do with mitosis, and chromosomes
Define cell cycle. Identify stages and substages and Describe the relative time spent in each
cell cycle- consists of interphase and mitotic cell division
- the cell spends much more time in interphase
interphase
G1- acquisition of nutrients and growth to proper size
S- when the DNA is replicated
G2- completion of cell growth and preparation for division of the cell into daughter cells
mitotic cell division
Prophase- chromosomes condense and shorten
late prophase- the nucleolus disappears, the nuclear envelope breaks down, some spindle microtubules attach to the centromere
metaphase- all the chromosomes line up
anaphase- sister chromatids separate and move to opposite poles
telophase- one set of chromosomes reaches each pole, nuclear envelopes start to form, microfilaments pinch around the equator
cytokinesis- each daughter cell receives one nucleus and half the cytoplasm
Describe the cellular structures involved in the process of mitosis and their role.
spindle fibers
centrioles
centromeres
Recognize and Explain chromosome arrangement during mitosis and how it differs from meiosis
in mitosis during metaphase the chromosomes are lined up, and in meiosis there are two next to each other, one maternal, and one paternal
Explain the example signaling pathway involved in cell cycle control
- growth factors bind to receptors in the cell
- signal transducers relay information
- activate transcription factors to turn gene transcription on
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