Cell Division - 16.1 Flashcards
Does the volume of the cytoplasm of cell grow faster than surface area?
Yes
Where do cells absorb nutrients and excrete waste?
The plasma membrane
What is the problem with the volume of cell increasing?
If the cell grew to much, the plasma membrane would be to small to meet the metabolic needs (cell must stop growing at a certain size)
What is spontaneous generation?
Living organisms can arise from non living matter
Who forced published the idea of cell division and when?
Rudolph Virchow - 1855
Which type of cells are replaced frequently?
Skin cells and Blood cells
Which cells do not divide frequently or at all?
Nerve cells
What is the single cell cycle define as?
The sequence of events from one cell division to the next
How can growing organisms develop properly?
New cells must carry the same function as the original cell
How do synthetic dyes work?
- Dye is used to stain a specimen
- Chromatin in the nucleus picks up the stain
What is the function and the structure of a cell determined by?
The genetic material
What is the genetic information of a cell contained in?
DNA (Deoxyribonucleic acid)
Where is DNA found?
Found in each chromosome of a cell
What is a chromosome?
Length of DNA and its associated proteins
Where are the chromosomes found in the eukoryotic cells?
In the nucleus
What material does DNA compact within the cell?
Histones (proteins)
What forms when threads of chromatin condense?
Chromosomes
What is the constricted region in a condensed chromosome called?
Centromere
How many chromosomes are in a human somatic cell?
46 chromosomes
What are autosomes?
22 pairs of homologous chromosomes
Will the two sex chromosomes always be homologous?
No
What are the X and Y chromosomes called?
Sex chromosomes
What makes chromosomes homologous?
- Carry the same genes (alleles of the genes) at the same location
- Same length and size
- Same banding
What does it mean to be diploid?
Pairs of homologous chromosomes
What does it mean to be haploid?
Unpaired chromosomes
What does it mean to be polypoid?
To have more than two homologous chromosomes
How do autosomes differ from one another?
- Vary in length
- Locations at the centromere
- Staining properties
What is a picture of all the autosomes?
Karyotype
How is a karyotype created?
- collecting a cell sample and use chemicals to stop the cycle
- stain cells help identify individual chromosomes
- Photographed stained chromosomes transfer images onto a new background
- Images are organized into a series of homologous pairs
What are the two main stages of the cell cycle?
Growth stage and division stage
What is the growth stage called?
Interphase
What happens in interphase?
Cells carries out metabolic functions and prepares for its next division
What are the three phases in interphase?
- G1 phase
- Interphase
- G2 phase
What happens in G1 phase?
Cell grows quickly during this phase - important growth processes are occuring
What happens in the S phase?
- Cells DNA is copied exactly
- DNA in the chromatin replicates to create a second set of identical chromatin
- Two identical sister chromatids are joined at the centromere
- New genetic material is synthesized
What happens in the G2 phase?
- Cell rebuilds its reserves of energy to prepare for cell division
- Cell manufactures proteins and other molecules
What does interphase end?
When the cell begins its process of nuclear division (mitosis)
What are the two main processes in cell division?
- Mitosis
- Cytokenesis
What is mitosis?
- Division of genetic material
- Contents of the nucleus are separated into complete and separate cells
What is cytokeneis?
The division of the cytoplasm and the organelles into separate cells
