Cell Cycle
Somatic cells
List the reasons for organisms undergo mitosis
Growth
Repair
Maintenance
Asexual reproduction
What kind of cells are produced by meiosis?
Gametes: eggs and sperm
Free space: what does RNA stand for?
Ribonucleic acid
What is the central dogma of biology?
DNA -> RNA -> Protein
What 3 things occur during the mitotic phase of the cell cycle?
1. DNA is condensed into chromosomes
2. Chromosomes moved to opposite side of the cell
3. 2 nuclei are formed
What is the difference haploid and diploid number? Explain how it relates to chromosomes.
The haploid number (n) is the base number of chromosomes an organism has. The diploid number (2n) the base chromosomes plus an identical homologous pair for each.
Humans n=23 2n=46
What two things from the basis of genetic diversity? Explain
Independent assortment: because chromosome in a homologous pair is unique there are many possible chromosome combinations for an gamete.
Crossing over: During meiosis the chromosomes in homologous pairs trade genes to make completely unique chromosomes (frakin-chromosomes ;)
What is a gene?
It is a section of DNA that codes for a single protein.
What is the basic unit of information in DNA and RNA?
How is the DNA replicated in S phase?
The DNA double helix is unzipped (splint) down the middle (two strands)
DNA polymerase copies the DNA by creating the bonds between the bases of the new strands
2 new stands are formed on each half of the original DNA
What are the benefits for asexual reproduction over sexual reproduction? What are the negative?
It is faster and requires less energy
There is no gain of genetic diversity
Explain how the chromosome count proceeds in meiosis. Use "n"
A 2n (diploid) germ line cell duplicates it DNA to 4n. The cell splits into two 2n daughter cells. Each daughter cell splits into two n (haploid) daughter cells. End result: Four n (haploid) gametes.
Explain alternative splicing for RNA and how it diverges from the central dogma.
The central dogma tell us that 1 gene codes for 1 protein.
Alternative splicing is when a different combination exons allows for more than 1 protein to be coded from the same gene.
What happens during mRNA processing?
Introns are cut out of the mRNA strand (and stay in the nucleus) while exons remain part of the strand. A 5 prime cap and a poly a tail are added.
List the checkpoints in the cell cycle and what they do.
G1 checkpoint: Large enough, growth factors, enough nutrients, is division necessary?
G2 checkpoint: Was the DNA replicated properly?
Metaphase checkpoint: are all chromosomes attached to microtubules?
Explain how bacteria reproduce
Cell division occurs in two step:
1. Replication: the circular DNA is copied
2. Binary fission: the cell wall is split
Why is sexual reproduction a challenge to Darwinism?
Because a special kind of cells, special structures to produce those cells, special organs, and mating behaviors would all have to be developed in two individual organisms and them same time for sexual reproduction to evolve. This is highly unlikely with to occur under the ideas of gradualism.
What does it mean that the DNA code is unambiguous and degenerate?
Unambiguous: each codon only codes for a single amino acid
Degenerate: more than 1 codon can code for the same amino acid
1. Initiation: promoters and transcription factors
2. Elongation: process continued
3. Termination (stop codon)
List the stages of the cell cycle
G0
Interphase
-G1
-S
-G2
Mitosis
Cytokinesis
Explain how the chromosomes count proceeds in mitosis. Use "n" to explain
1 somatic 2n (diploid) parent cell replicates its DNA to 4n. After mitosis and cytokinesis the cell is split into two 2n (haploid) daughter cells.
Explain the red queen hypothesis
Sexual reproduction produces genetically varied offspring each generation. The random genetic diversity from one generation to the next is just enough for a population to adapt to a changing environment.
Give an example of a gene mutation and how it effects a proteins primary structure.
Point mutations
Base deletions, substitution, and insertions. When a base if changed then the meaning of the code is changed which will result in a completely incorrect chain of amino acids.
List the step of transcription and translation in order.
Transcription:
DNA is unzipped
RNA polymerase creates an mRNA strand from the DNA code
The mRNA is processed
Translation:
The mRNA runs through the ribosome (rRNA) while tRNA brings amino acids based on the mRNA sequence.