Mr. Mateki second test Flashcards
Why do cells not keep growing infinitely, and reproduce instead?
In regards to the species as a whole
To reduce the possibility that an entire species fails, because if there is only 1 huge cell and it dies, there goes the species
Why do cells not keep growing infinitely, and reproduce instead?
In regards to DNA
The larger a cell becomes the more demands it has on its DNA. If a cell grew too large, the result would be “information overload”
Why do cells not keep growing infinitely, and reproduce instead?
In regards to surface area/volume.
The volume of a cell grows faster than its surface area. Therefore, a large cell has trouble moving enough food in and enough waste out.
Cell division (mitosis) definition
when a cell divides into two new daughter cells.
- copy of DNA is made
Asexual reproduction
a process by which a single parent reproduces by itself
- offspring have the same genetic information as the parent
(can be done by single or multicellular organisms)
Advantages of asexual reproduction
Much simpler and faster than sexual reproduction
Disadvantages of asexual reproduction
lack of genetic diversity can become a disadvantage
Sexual reproduction(Meiosis)
a process by which two cells from different parents fuse, or join together, to produce the first cell of a new organism
Advantages of sexual reproduction
produces genetic diversity
Disadvantages of sexual reproduction
takes more time than asexual reproduction
Male gamete
sperm
Female gamete
egg/oocyte
Chromosomes
each molecule of DNA is packaged into a chromosome
How do chromosomes help with cell division
Chromosomes make it possible to separate DNA precisely during cell division
P arm definition
The short arm of a chromosome
Q arm definition
The long arm of a chromosome
Centromere definition
The center of a chromosome
Nucleotides (bases)
code for genes
DNA sequence
every DNA sequence corresponds to one of the 20 amino acids. The sequence is different in every person.
Prokaryotic Chromosomes
Usually, their genetic material is contained in a single, circle shaped chromosome. The DNA molecules of Prokaryotes are found in the cytoplasm.
Eukaryotic Chromosomes
because eukaryotes have much more DNA than prokaryotes, the cells in our body have 46 chromosomes. These are contained in the nucleus.
Chromatid
the condensed form of DNA.
When does DNA condense
DNA condenses when it is associated with histones.
Chromatin
short sequence that makes up chromatid
Spindle fibers
help separate duplicated chromosomes
Histones definition and how many
there are 8 histones. Allow DNA to coil in a systematic and organized way.
Active transport
when we actively pump something out. Takes energy.
What happens to animals if they are put in a different environment
They will die
What is humanities biggest strength?
the ability to adapt
G1 phase of interphase in the eukaryotic cell cycle
cell growth. Proteins are made.
S (synthesis) phase of mitosis in the eukaryotic cell cycle
DNA replication. DNA is doubled
G2 phase of interphase in the eukaryotic cell cycle
preparation for mitosis. Organelles are doubled.
Mitosis definition in the eukaryotic cell cycle
Cell division, both cells are identical. Starts with a diploid cell and ends up with 2 diploid cells.
Prophase in the eukaryotic cell cycle
Nuclear envelope is dissolved. Ends with DNA floating in cytoplasm. Centrioles are formed, and centrioles migrate to opposite sides
Metaphase in the eukaryotic cell cycle
Centrioles have finished migrating. Chromosomes line up in the middle.
Anaphase in the eukaryotic cell cycle
Individual chromosomes are pulled to either side by the centrioles.
Cytokinesis
when the cells actually separate
External regulators
proteins that respond to events outside the cell
Growth factors
important external regulators
What type of proteins control the cell cycle when you have an injury?
Growth factor proteins control the cell cycle when you have an injury.
Internal regulators
proteins that respond to events inside the cell. They control stages of the cell.
What controls the cell cycle
The cell cycle is controlled by regulatory proteins, both inside and outside the cell
Cancer
a disorder that shows what happens when cell growth is not controlled
What causes cancer
damage to a cell’s DNA
Tumor definition
A mass of cancer cells.
Treatments for cancer
Doctors can remove tumors with surgery if they are found early
They can also use chemotherapy, which treats cancer with chemical compounds
