Mechanism of Heredity
Cell Division I
Cell Division II
Meiosis I
Meiosis II
100
Genetics is the study of _____.
Heredity
100
What are the three major phases of the cell cycle?
Interphase, Mitosis, Cytokinesis
100
What is mitosis?
The division of the nuclear material so that each new nucleus has a complete identical copy of genetic information.
100
What does it mean to be haploid(n)? Diploid(2n)?
Haploid means it has one copy of each chromosome. Diploid means there are two copies of each chromosome.
100
What is meiosis?
The reduction of a cell's chromosome number from diploid to haploid by two consecutive cell divisions.
200
What is a gene?
A section of DNA that produces a particular polypeptide chain that causes a particular trait.
200
In this phase of mitosis, the chromosomes line up on the equatorial plane.
Metaphase
200
What is cytokinesis?
Division of the cytoplasm of the cell during cell division.
200
What is a gamete?
A haploid cell used for sexual reproduction.
200
When two haploid cells unite, a diploid _______ is formed.
Zygote
300
Who discovered chromosomes in 1882?
Walther Flemming
300
Tell the three phases of Interphase and briefly describe what happens in each.
G1 - increase in size, makes new organelles and synthesizes proteins S - chromosomes are duplicated G2 - produces proteins and other molecules needed for mitosis
300
Describe what happens during cytokinesis of a human or animal cell.
The cytoskeleton begins to form a contractile ring that pinches the plasma membrane in until it fuses and forms two daughter cells.
300
During Metaphase I of meiosis, ______ line up on the equatorial plane.
Tetrads
300
In Prophase I of meiosis, a process called ________ occurs where homologous chromosomes pair up forming a structure called a _________ .
Synapsis; Tetrad
400
What is a karotype?
A picture of a complete set of chromosomes usually cut up and arranged in pairs.
400
Name three things that happen during prophase in mitosis.
Chromosomes get short and thick as they coil up and become visible. The nuclear membrane disintegrates. The nucleolus disappears. In the cytoplasm, the centrosomes migrate to opposite poles of the nucleus.
400
Describe plant cell cytokinesis.
Small vesicles begin to align and fuse to form the cell plate. Later cellulose and other cell wall components are added to to the cell plate to form a cell wall.
400
What are the products of oogenesis?
One egg (ovum); Three Polar bodies
400
What is the term used to describe the process where gametes are united?
Fertilization
500
After a chromosome duplicates, it consists of two identical halves called ________ and are joined at a constricted area called the ___________.
Sister chromatids; centromere
500
What is the function of the mitotic spindle?
It directs the movements of the chromosomes during mitosis.
500
What do unicellular cells use mitosis for? What do multicellular cells use mitosis for?
Unicellular - asexual reproduction Multicellular - growth, repair and replacement of cells
500
What is the difference in the end result between spermatogenesis and oogenesis?
Spermatogenesis results in four fully functional haploid cells that are mobile. Oogenesis results in one functional haploid cell that is not mobile.
500
Name the differences between mitosis and meiosis in regards to: The end result Metaphase I Anaphase I
End Result: mitosis - 2 cells with same # chromosomes as parent cell meiosis - 4 haploid cells Metaphase I: mitosis - individual chromosomes line up on equatorial plane meiosis - tetrads line up on equatorial plane Anaphase I: mitosis - sister chromatids separate and move to opposite poles of the cell meiosis - tetrads separate and move to opposite poles of the cell
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