Bio 10 Flashcards
(43 cards)
cell division
after growth a cell divides into 2 daughter cells
DNA overload
when the molecules needed are too much for the amount of DNA there is too code for them
Why don’t cells just keep growing?
- DNA overload
- Material Transport
What problems to material transport does a large cell pose?
A too large cell has too much space to be efficient. Any molecules take a while to move from point a to point b
how is the SA/V ratio effected by size of cell
The larger the cell, the smaller the ratio
What are the main 4 phases of the cell cycle
G1- cell growth
S- replicate chromosomes
G2- preparefor mitosis
M- cell devision
What are the three types of of cell division and what kinds of cells use them?
- Procaryotic- Binary fission
- Eucaryotic- asexual reproduction-cell cycle
- Formation of Gametes- CHAPTER 11!!
True or False: DNA must be passed on during cell division
TRUE!!
Binary Fission
Cell division of prokaryotic cells
- Stage 1- DNA is copied
- Stage 2- Cell divides
Genes
segments of DNA coding for a specific thing
DNA
deoxyribonucleicacid
- nucleic acid containing thousands of genes
Chromosome
Structures of tightly wound DNA and histone proteins
CAN BE ONE OR TWO
Chromatids
One of the pair of strands making up a x chromosomes
two are called sister chromatids
Centromere
the point in the middle of a chromosome where the sister chromatids meet together
Interphase
G1, S, G2, where the cell grows and prepares for division
mitosis
the first phase of the M phase where the nucleus divides
When can you see chromosones
During cell divisions the chromosones condense and become visible
What are the 4 phases of mitosis
prohpase (longest)
metaphase
anaphase
telophase
How long does mitosis take?
between a few minutes and a few days
Prophase
The first phase of mitosis taking 50-60 % of time
- chromosomes condense
- centrioles move apart off of centrosome
- nuclear envelope dissolves
How are spindles formed and what happens to them after they are formed?
The spindles are structures made up of both centrioles and microtubules:
as the centrioles move off of the centrosome in the Prophase, the spindles are formed
After the chromosomes have been split the spindles dissolve into the cell.
centrosome
an area in the cell where centrioles usually rest
metaphase
2nd phase
Chromosomes line up in the middle of the cell at the equator/metaphase plate because spindles play “tug of war” with each sister chromatid
equator vs. metaphase plate
TRICK QUESTION!!
they are the same thing, they are the theoretical line where chromosomes line up during the metaphase