Chapter 10: Why Do Cells Reproduce? Flashcards
Prokaryotic Genomes
Contained in a singular, circular DNA molecule
Eukaryotic Genomes
Divided into multiple linear chromosomes.
Chromosome
A threadless structure of nucleic acids and protein found in the nucleus of most living cells, carrying the genetic information in the form of genes.
Genes
A unit of heredity, which is transferred from a parent to offspring and is held to determine some characteristics of the offspring.
Traits
A genetically determined characteristic.
Difference between Somatic and Gametes
Somatic (body) cells contain 46 chromosomes (23 pairs) and are identical to the parent cell.
Gamete (sex) cells contain 23 chromosomes and are varied from the parent.
Difference between Haploid and Diploid cells
Haploid cells contain only 1 set of chromosomes (n). Meiosis
Diploid contains 2 sets of chromosomes (2n). Mitosis
Chromosomes Compaction
The long strands of DNA are condensed into compact chromosomes for protection during cell division.
3 Stages of Interphase
- G1 phase = cell growth
- S phase = DNA synthesis
- G2 phase = cell growth
Key Events that occur during Mitosis
- Interphase
- Propose
- Metaphase
- Anaphase
- Telophase
Prophase
Break down of nuclear envelope
Chromatic condenses into chromosomes
Mitotic spindle forms
Cross over happens in Meiosis Prophase 1.
Metaphase
Line up @ equator
Spindles attach to chromosomes
Anaphase
Cell elongates
Sister chromatids separated in Mitosis and Meiosis 2
Homologous pairs separated in Meiosis
Telophase
Cleavage furrow
Nuclear envelope reforms
Cytokinesis
Separation of cytoplasm during cell division
G1 gate
Checks for proper cell size
Delays if not proper cell size
G2 gate
Checks to make sure replicated chromosomes are all there.
M gate
Checks for mitotic spindle.
Positive regulators
Growth hormones - increase cell division
Negative regulators
Tumor suppressor genes that slow down cell division to prevent out of control replication.
Three genetic mutations that can cause cancer
- Oncogenes - excessive growth factor
- BRCA1 and BRCA2 failure
- Epigenetic (p53) - mutations that happen around the DNA
Describe out cancer is cause by uncontrolled cell growth
Mutation is tumor suppressor genes that result the cells to divide faster than can be regulated properly.
Protooncogene vs. Oncogene
Protooncogene is a normal cell.
Oncogene cells prevent cell death. Resulting in uncontrollable replication of mutated cells.
How do tumor suppressors function?
They delay the cell division.
Repair DNA damage if possible.
Initiate cell death - Aptosis - if repair is not possible.
