Terms in this set (42)
How many chromosomes are in the body cells of an organism that has a haploid number of 16?
A chromatid is attached to a spindle fiber by the __________.
When an area of a chromatid is exchanged with the matching area on a chromatid of its homologous chromosome, _________________ occurs.
A: centromere B:chromatid
How many cells are produced from meiosis?
When does crossing over occur in meiosis?
in prophase 1
What are two halves of a doubled chromosome structure called?
Franklin was the first to suggest that DNA is what?
a double helix; she was the first to find pictures and research of DNA
When during the cell cycle is a cell's DNA replicated?
How long does it take the average cell to go through interphase?
90% of the time or 23 hours
What is the difference between anaphase of mitosis and anaphase 1 of meiosis?
In anaphase (mitosis) sister chromatids get pulled apart to opposite ends of the cell. But in anaphase 1 (meiosis) the WHOLE chromosome is moved to the opposite ends of the cell.
In plant cells, what happens in cytokinesis?
in cytokinesis, plants form a cell wall, while animal cells just form a cell membrane
What is the longest phase of the cell cycle?
How long does it take the average cell to go through mitosis?
A typical human cell contains 46 chromosomes. How many chromosomes does the cell have after mitosis and cell division?
What happens in crossing over?
It is when chromosomes pair up w/ each other (pair up with the corresponding parts) and exchange different segments of their genetic material. Which results in chromosomes with genetically diverse traits or when an area of a chromatid is exchanged with the matching area on a chromatid of its homologous chromosome
What are three stages of the cell cycle?
interphase, mitosis, and cytokinesis
How many cells are produced from mitosis?
A gene is a segment of DNA that controls the production of ____________.
The diploid number of chromosomes in a human skin cell is 46. How many chromosomes are found in a human ovum?
4 phases of cell division (PMAT)
when a sperm and egg unite
one copy of a newly copied chromosome which is joined by the other copy by the centromere
packaged and organized structure containing most of DNA of a living organism
process in which a sex cell is made; reproduction of gametes
the material of which the chromosomes of organisms are composed?
What is happening in anaphase and anaphase 1?
anaphase: sister chromatids get pulled apart to opposite ends of the cell.
anaphase 1: the whole chromosome is pulled to the opposite ends of a cell
What is happening in metaphase and metaphase 1?
metaphase: spindle fibers attach to the centromere of a chromosome. The chromosomes are lined up at the equator.
metaphase 1: spindle fibers attach to the centromeres of the chromosomes. The chromosome and its PARTNER are lined up at the equator.
What is happening in cytokinesis?
the membrane pinches off the cells; the cell divides
What is happening in prophase and prophase 1?
prophase: nuclear membrane disappears, centrioles migrate to opposite sides of the cell, spindle fibers appear, and chromatin winds up to chromosomes.
prophase 1: same as prophase but in prophase 1, crossing over occurs
What is happening in interphase?
the cell is growing and DNA is replicated
What is happening in telophase and telophase 1?
telophase: chromosomes clump at the ends of the cell, nuclear membrane comes back, spindle fibers disappear, and chromosomes unwind
telophase 1: the same thing but but the chromosomes don't unwind and don't clump at the ends of the cell.
Are the chromosomes in the newly formed cells diploid or haploid? (in meiosis)
In mitosis, replication of chromosomes precedes each cell division. In meiosis, two cell divisions take place without a replication of chromosomes between them. What is the significance of this difference?
In meiosis, it is important to not replicate the chromosomes a second time, in interphase, because then the 4 new gametes would have too many chromosomes and the cell would not survive.
What are the four phases of mitosis? (in order)
prophase, metaphase, anaphase, telophase.
What are ALL the stages of the cell cycle?
interphase, mitosis, and cytokinesis
In the process of meiosis, how many nuclei are produced from the nucleus of each parent cell?
4 nuclei are produced from the nucleus of each parent cell.
How does the number of chromosomes in each newly formed cell compare to the number of chromosomes in a parent cell?
The number of chromosomes in a newly formed cell is only HALF the number of chromosomes as the parent cell.