Reproduction and Developement Flashcards
Interphase is a phase in which DNA is uncoiled in the form of chromatin. What are its three stages called?
G1, S, and G2
In this cell stage, cells create organelles for energy and protein production, while also increasing their size. To move on, a restriction point is held. This is also the longest phase in interphase.
G1 Stage
A point during which DNA is checked for quality must be passed for the cell to move into S stage.
Restriction Point
In this cell stage, DNA is replicated (23 to 46). The strands of DNA (chromatids) are held together at the centromere.
S Stage
In this cell stage, there is further cell growth and replication of organelles in preparation for mitosis. Another quality checkpoint must be passed for the cell to enter mitosis.
G2 Stage
In this stage, mitosis and cytokinesis occur.
M Stage
What happens in prophase of mitosis.
- Chromasomes condense
- Nuclear membrane dissolves
- Nucleoli disappear
- Centrioles migrate to opposite sides of the cell
- Spindle apparatus forms
- Kineticore of each chromosome is contacted by a spindle fiber
What happens in metaphase of mitosis.
Chromosomes line up along the metaphase plate (equitorial plate).
What happens in anaphase of mitosis.
Sister chromatids are separated and pulled to opposite poles.
What happens in telophase of mitosis.
- Nuclear membrane reforms
- Spindle apparatus disappears
- Cytokinesis
What happens in prophase I of meiosis?
The same as mitosis, except with the addition of:
- Synapsis
- Crossing over of tetrads (Mendel’s Second Law of Independent Assortment)
What happens in metaphase I of meiosis?
Homologous chromosomes line up on opposite sides of the metaphase plate.
What happens in anaphase I of meiosis?
Homologous chromosomes are segregated to opposite poles of the cell (Mendel’s First Law of Segregation).
What happens in telophase I of meiosis?
Chromosomes may or may not fully decondense and the cell may enter interkinesis after cytokinesis.
Sperm is developed where?
In the seminiferous tubules of the testes.
What nourshes the developement of sperm?
Sertoli Cells
What cells secrete testosterone and other male sex hormones?
Interstitial Cells of Leydig
When sperm gain motilityy, where are they stored until ejaculation?
Epididymis
How does sperm travel during ejaculation?
Vas deferens > Ejaculatory Duct > Urethra > Out of Penis
This contributes fructose to nourish sperm and produce alkaline fluid.
Seminal Vesicles
Produces alkaline fluid.
Prostate Gland
Produce a clear viscous fluid that cleans out any remnants of urine and libricates the urethra during sexual arousal.
Bulbourethral Glands
What part of the sperm contains genetic material and is covered with an acrosome?
Head of Sperm
A modified golgi apparatus that contains enzymes that help the sperm to fuse to and penetrate the ovum.
Acrosome
What part of the sperm generates ATP from fructose and contains many mitochondria?
Midpiece of Sperm
Primary oocytes are arrested at what phase?
Prophase I
Secondary oocytes are arrested at what phase?
Metaphase II
Cytokinesis of the oogenesis is uneven and results in one cell receiving very little cytoplasm and organelles. What is this called?
Polar Body
An acellular mixture of glycoproteins that protect the oocyte and contain the compounds necessary for sperm binding (surround the oocyte).
Zona Pellucida
A layer of cells that adhere to the oocyte during ovulation.
Corona Radiata