Intorduction To Reproduction And Endocrinology Flashcards
•Life cycle of a cell is referred to as the ____
•CC = _____
Cell Cycle-CC
ordered set of events, culminating in cell growth & division into 2 daughter cells.
‘’ ______ is a process of cell division resulting in ______ daughter cells.
̈ All ______ divide by mitosis; the _____ divide by meiosis to produce _____.
̈ The period between mitosis is called the _____ which covers the ____ , ____ and ___ phases of CC.
̈ During ___ phase, DNA has been replicated and the chromosome number is ____
̈ In the ______, chromosomes are not visible by ______ because chromatin diffuses throughout the nucleus.
̈ Mitosis ends with _____
• Mitosis, 2 genetically equivalent
• Body cells; germ cells,gametes
•Interphase; G1,S and G2
• G2; 4n
• Interphase,Light microscopy
• 2 identical cells (2n)
_____ is a special type of cell division resulting in ______ daughter cells, each containing _____ the number of chromosomes of the parent cell.
̈ ______ (____& ____) are produced by meiosis.
̈ Meiosis —> produces cells half chromosome number = _____ (sperm & egg - _____).
̈ Fertilization (sperm + egg) —–> chromosome number = _____
̈ 2 Divisions: ______ & ______
• Meiosis;4 genetically nonequivalent;half
• Germ cells(eggs and sperms)
•23;haploid
• 46
• Meiosis I and Meiosis II
̈ The Meiosis involves ___ consecutive cell divisions.
̈ Each division is composed of ____ stages as in mitosis.
” However, the 1st division differs in some important aspects. What stages in meiosis I are different from mitosis ?
• two(2)
• Four(4)
• Prophase I.
Metaphase I
Anaphase I.
In Prophase:
• Chromosomes ____.
• SYNAPSIS - homologs ___ together = ____.
• CROSSOVER - exchange occurs at a ____
In Metaphase I = chromosomes ____.
In Anaphase I = chromosomes _____
In Telophase I = chromosome at poles - ______.
̈ Meiosis I separates _____ of homologous pair
• condense
• PAIR , tetrad
• chiasma
• align at equator
• migrate towards the poles
• cell domains separate
• Homologs
List the five substages of Prophase I
- Leptotene
- Zygotene
- Pachytene
- Diplotene
- Diakinesis
• After the 1st division of Meiosis the chromosome number in each daughter cell becomes ____.
̈ The process of the 2nd division is the same as in mitosis except that there is ________. As a result, the produced cell is a ____ .
• 2n
• no DNA replication during interphase
• haploid (1n)
• Meiosis II is similar to mitosis but without an ____
• Separates ______ of ____ homolog of the homologous pair just as is in mitosis.
• In human oocyte, Meiosis I is completed shortly before _____.
• Meiosis II starts without ______.
• Once secondary oocyte shows spindle,
_____ occurs.
• Meiosis II is completed at ______
• S phase
• chromatids,one
• ovulation
• DNA replication
• ovulation occurs
• Fertilization
Gametogenesis:
Spermatogenesis:
Oogenesis:
• Gamete formation by Meiosis
• Sperm formation (1n)
• Egg formation (1n)
Spermatogenesis occur has a ___-day cycle which is subdivided into ____ stages with each stage lasting for different lengths of time.
• 74 day cycle
• Four
Pertaining to spermatogenesis:
First stage:
Second stage:
Third stage:
Fourth stage:
Mitosis of the primary spermatogonia lasts 20 days, Up to the primary spermatocytes
First meiosis lasts ~28 days For the division of the primary
spermatocytes to form secondary spermatocytes
• Second meiosis lasts a few hours For engendering the spermatids
• Spermiogenesis 21-24 days Up to the completed sperm cells
• Germ cell comprise _____ and ____
• ________ is the physiological changes spermatozoa must undergo in order to have the ability to penetrate and fertilize an egg. It is the _____ step in the maturation of mammalian spermatozoa and is required to render them competent to _____ an oocyte.
• Ovum is a _____ oocyte arrested at _____ in the second meiotic division
• Spermatozoon and Ovum
• Capacitation; penultimate; fertilize
• secondary oocyte; metaphase II
Process of fertilization
The Sperm binds to ______ to induce ______.
• Sperm receptor ZP-3
• Acrosome reaction
Acrosome reaction is the release of _____
acrosomal enzyme
The second meiotic division of the secondary oocyte is rapidly completed when _____ occurs and the ______ is released, leaving a ___ female nucleus.
Fertilization
Second polar body
Haploid
