Flashcards in Biology - Cell Cycle Deck (28):
What is another name for body cell and how many chromosomes?
What is another name for sex cell and how many chromosomes?
What happens in interphase?
- cell grows and carries out regular cellular functions
- cell duplicates DNA to prepare for mitosis (each of the 46 DNA molecules now consist of 2 identical sister chromatids)
What happens in mitosis?
- division of DNA
- must occur before cell divides
- ensures that complete set of DNA is given to each daughter cell
What is visible in interphase?
nucleus + nucleolus + nuclear membrane
Mitosis allows what?
- single cells to reproduce
- multicellular organisms to grow and develop
- tissues to be repaired
- old worn out cells to be replaced
Each body cell has __ DNA molecules; __ from maternal set and __ from paternal set
46 DNA molecules (23 from maternal, 23 from paternal)
During interphase, DNA molecules gets copied to now each of __ molecules contain ___________.
46 DNA molecules get doubled; each 46 DNA molecules contain 2 identical sister chromatids
Alone, a strand of the sister chromatids would be called _______. The sister chromatids are held together by __________.
Sister chromatids are held together by a centromere
What is cytokinesis and the end result?
- the division of cytoplasm + organelles
- end result is 2 genetically identical daughter cells
What happens in animal cytokinesis?
a band of protein squeezes cell membrane in middle, forming cleavage furrow until cytoplasm splits
What happens in plant cytokinesis?
cell plate grows in the middle outward, sealing contents of new cells from each other
What happens in prophase?
- chromatin condense to chromosomes made up of 2 sister chromatids
- nuclear membrane starts to dissolve, releasing chromosomes into cytoplasm
- centrioles move to opposites poles with spindle fibers
What is visible in prophase?
maybe nucleus + nucleolus + nuclear membrane, chromatids, chromosomes, and spindle fibers
What happens in metaphase?
- chromosomes line up along equatorial plate
- nuclear membrane dissolves completely
What is visible in metaphase?
chromatids, chromosomes, spindle fibers
What happens in anaphase?
- sister chromatids separate into daughter chromosomes, pulled to other end of cell by spindle fibers (which contract opposite ways)
What is visible in anaphase?
chromosomes, spindle fibers
What happens in telophase?
- chromosomes reach opposite ends of cell and lengthen to chromatin
- new nuclear membrane + nucleus + nucleolus form at each end of cell
- spindle fibers break down and disappear
What is visible in telophase?
nucleus + nucleolus + nuclear membrane, maybe chromosomes
What are spindle fibers?
a network of protein which grows from centrioles and attach to the centromere of each DNA molecule
What is the equatorial plate?
located in middle of cell, equal distance away from 2 poles and perpendicular to spindle fibers
The process of producing offspring by the fusion of 2 gametes; the production of offspring that have genetic information from each parent
The process of producing offspring from only one parent; the production of offspring that are genetically identical to the parent
What do all organisms need to survive?
cell division + source of energy + nutrients + water + gases to survive
As multicellular organisms, why do number of cells increase instead of size?
Chemicals used during cell activity/growth enter across the membrane and travel through diffusion; where chemicals move from an area of higher concentration (amount of solute in a solution) to lower. Water enters and leaves in a process called osmosis whereas water moves in the direction of greater solute concentration. But when a cell gets too large, these necessary chemicals/water cannot move through the cell fast enough and will die!
How does a minor cut heal over time?
Every day, your body sheds millions of dead skin cells, all of which are replaced by new ones. If you get a cut, cells divide to fill in the gaps.