Meiosis and Reproduction 1
How many chromosomes do gametes hold?
23
How many chromosomes do diploids hold?
46.
What is the longest phase?
Interphase.
What does crossing over contribute to?
Genetic variation.
What is a centromere?
The part of a chromosome that ties together two chromatids. The middle part of the chromosome.
What type of reproduction involves two parents in which their offspring is genetically different?
Sexual reproduction.
What are all the phases of interphase?
G0, G1, G2, and S phase.
What is fertilization during reproduction?
Fertilization is the combination of male and female gametes to produce a zygote.
What do spindle fibers do?
They separate and move genetic material in a cell.
What type of reproduction only involves one parent and its offspring is genetically identical?
asexual reproduction.
What is one thing that occurs during the metaphase?
Chromosomes line up along the meta-phase plate in the middle of the cell.
What is one thing that happens during prophase?
Chromosomes condense, becoming visible, the nuclear membrane dissolves, the centrosomes move to opposite ends of the nucleus, and spindle fibers form.
What is one thing that occurs during the anaphase.
Spindle fibers begin to shorten, separating the sister chromatids and pulling them to opposite ends of the cell.
What is one thing that occurs during telophase?
The genetic material separates and the nuclear membrane begins to re-form to create two separate but identical nuclei.
What is one thing that occurs during cytokinesis?
The plasma membrane begins to cleave the cytoplasm into two separate but identical cells.
This is the phase of meiosis ll when the nuclear envelope reforms around each set of separate chromatids.
Telophase ll.
In what phase of meiosis does independent assortment occur?
Metaphase l.
What happens during the inter-phase?
The cell grows larger and replicate its DNA in order to prepare for cell division.
What phase of meiosis does crossing over occur?
Prophase l.
The phase of meiosis ll when chromosomes line up individually at the cell's equator, not in homologous pairs.
Metaphase ll.
What is the difference between prophase l and prophase ll.
In prophase l homologous chromosomes pair up and crossing over occurs, in prophase ll, chromosomes do not pair and no crossing over happens.
What is the difference between anaphase l and anaphase ll.
Anaphase l pulls homologous chromosomes apart, while anaphase ll pulls sister chromatids apart.
Difference between metaphase l and metaphase ll.
In metaphase l, homologous chromosomes pairs (tetrads) line up at the cells equator, while in metaphase ll, individual chromosomes line up single file, and sister chromosomes prepare to separate.
Difference between telophase l and telophase ll.
In telophase l, two haploid cells form, but chromosomes are still made of sister chromatids. In telophase ll, four haploid cells form, and chromosomes are now single chromatids.
Difference between cytokenisis l and cytokenisis ll.
In cytokenisis l, the cytoplasm divides to form two haploid cells with duplicated chromosomes. In cytokenisis ll, the cytoplasm divides again, producing four haploid cells with single chromosomes.