Chapter 5+5.5: Cell Division Flashcards
What are the factors that limit cell growth?
- demands on DNA
2. exchange of materials
How do materials move within the cell?
diffusion
How are materials transported across the cell membrane?
diffusion from a higher concentration to a lower concentration
How are the surface area and volume ratios related?
the cell can no longer act efficiently once it reaches a certain point, so it must divide
What are the advantages of sexual reproduction?
- diverse offspring
- adaptability
- can live in different environments
What are the disadvantages of sexual reproduction?
- time-consuming
- genetic malfunction
- imbalances the ecosystem
What are the advantages of asexual reproduction?
- quick process
- many organisms are produced
- energy-efficient
What are the disadvantages of asexual reproduction?
- lack of diversity
- unable to adapt to changing environments
- risk of overpopulation
What are the stages of the cell cycle?
- G1
- S
- G2
- M phase
What happens in each stage of the cell cycle?
G1: cell growth and DNA assessment
S: cell replication and chromosome replication
G2: DNA replication and assists in production of organelles and molecules specific to cell division
cyclins
proteins that regulate the timing of the cell cycle in eukaryotic cells
What are the parts of a chromosome?
- sister chromatids
2. centromere
sister chromatids
2 identical chromosomes
centromere
a region of microtubules where the spindle attaches
What are the phases of mitosis?
- prophase
- metaphase
- anaphase
- telophase
What occurs in each phase of mitosis?
prophase: breakdown of the nuclear membrance; centrioles separate and spindles start to form
metaphase: chromosomes line up at the equator of the cell; spindles attach to the centromere of chromosomes
anaphase: chromatids separate from each other; chromosomes migrate along the spindles to opposite ends of the cell
telophase: chromosomes reach opposite ends of the cell and distend into chromatids
What do spindle fibers do?
separate chromosomes
When are chromosomes shown in a cell?
during metaphase
Are parent cells and daughter cells identical?
yes
What does mitosis in plant cells do?
forms a cell plate between the new cells that will eventually develop into a cell wall
What does mitosis in animal cells do?
produces identical copies of a cell
cancer
a cell that do not respond to the signals that regulate growth throughout most cells
What are the causes of cancer?
- smoking
- radiation exposure
- viral infection
- chemical exposure
tumor-supressor gene
p53 stops the cell cycle until chromosomes have been properly regulated
