ch 10 & 11 (cell growth & division) Flashcards
what are the main reasons why a cell cannot get too big
- the larger a cell becomes, the harder it is for the cell to move enough substances through itself
- a large cell also puts more demands on DNA
what is meiosis
gamete production
what are the phases of the cell cycle and what happens in each one?
G1 phase- cell growth
S phase- DNA replication
G2 Phase-Preparing for mitosis
M phase- Mitosis and cell division
what is mitosis divided into
prophase, metaphase, Anaphase and telophase
what is mitosis
the division of the nucleus
what is cytokines
the division of the cytoplasm
what is cell division
the process by which a cell divides into 2 daughter cells
how dose cell division solve problems of increasing size
by reducing cell volume
centromere
the area where a pair of chromatin attach
what is the cell cycle
the series of events that a cell goes through as they grow and divide
what is the spindle
a fan-like micro tube structure that helps separate chromosomes
during meiosis 1 what happens in inter-phase 1?
cells undergo a round of DNA replication, forming duplicate chromosomes
during meiosis 1 what happens in phrophase 1
each chromosome pairs with its corresponding homologous chromosome to form a tetrad
during meiosis 1 what happens in metaphase 1
spindle fibers attach to the chromosomes
during meiosis 1 what happens in anaphase
the fibers pull the homologus chromosomes toward opposite ends of the cell
during meiosis 1 what happens in telophase and cytokinesis
nuclear membranes form. the cell separates into two cells
during meiosis 2 what happens in phrophase 2
meiosis 1 results in two haploid (N) daughter cells, each with half the number of chromosomes as the original cell
during meiosis 2 what happens in metaphase 2
the chromosomes line up in a similar way to the metaphase stage of mitosis
during meiosis 2 what happens in anaphase 2
the sister chromatids separate and move toward opposite ends of the cells
during meiosis 2 what happens in telophase 2 and cytokinesis
meiosis 2 results in 4 haploid (N) daughter cells.
2N
diploid
N
haploid
what are the two main stages of cell division
mitosis and cytokinesis
chromosomes
- passes genetic info. from a generation to another
- made of DNA bound to proteins
when a cell divides in the cell cycle what is formed
two genetically identical daughter cells
what happens in interphase during the cell cycle
the cell grows and replicates its DNA and centrioles
what happens in prophase during the cell cycle
the chromatin condenses into chromosomes. The centrioles separate, and a spindle begins to form. the nuclear envelope breaks down
what happens in metaphase during the cell cycle
the chromosomes line up across the center of the cell each chromosome is connected to a spindle fiber at its centromere
what happens in anaphase during the cell cycle
the sister chromatids seperates into individual chromosomes and are moved apart
what happens in telophase during the cell cycle
the chromosomes gather at opposite ends of the cell and lose their distinct shapes. Two new nuclear envelopes will form
what happens in cytokinesis during the cell cycle
the cytoplasm pinches in half. each daughter cell has an identical set of duplicite chromosomes
what are 3 different types cell cycle regulations
cyclins, INternal regulators,external regulators
cyclins,
regulate the timing of cell cycle in eukaryotic cells
iNternal regulators
proteins that respond to events inside the cell
external regulators
protines that respond to events outside the cell
cancer
uncontrolled cell growth
cells that do not respond to signals that regulate the growth of the cells
what are some causes of cancer
smoking tobacco
radiation exposure
viral infection
what gene is linked to cancer
p 53, which normally halts the cell cycle unti all chromosomes have been properly replicated
what are gamates, what are they specificly in male and females
sex cells
females- eggs
males-sperm
what are some other reasons why cells divide
growth
repair
asexual reproduction
diploid/2N
- fullest set of chromosomes
- contains two sets of homologous chromosomes
how many chromosomes doe a human cell have
46
where do you get your 46 chromosomes?
23 from mom
23 from dad
haploid/N
1/2 set of chromosomes
what cells are haploids in humans, how many chromosomes do they have
sex cells/gamates
23 chromosomes
what are the two stages of meiosis
meiosis 1 and meiosis 2
tetrad
a structure formed by chromosomes paring with is corresponding homologous chromosome
(paring of homologous chromosomes)
WHEN Chromosomes are normally visible
when the cell is undergoing the metaphase of cell division
what is crossing-over
when tetrads exchange portions of their chromatids
what are some similarities between mitosis and meiosis
- both processes begin with diploid cells
- both considered as cell division
what are some differences between mitosis and meiosis
mitosis
produces 2 genetically identical diploid cells,asextual reproduction,1 division
meiosis
produces 4 genetically different haploid cells, sextual reproduction, 2divisions
what is a homologous chromosome
chromosomes that are approximately the same size and contain same types of genes in the same locations
