Lecture 1

What is the process of cell replication that results in two diploid cells?

Mitosis

What are the two types of cell division involved in gametogenesis?

Mitosis and Meiosis.

How many chromosomes do haploid cells contain? Include the number of autosomes and sex chromosome(s)

23 chromosomes - 22 autosomes and 1 sex chromosome

What is the term used for sperm formation in males?

Spermatogenesis.

How many chromosomes does 1 diploid cell end with at the end of mitosis and what are the different types of chromosomes? 

22 pairs of autosomes and 1 pair of sex chromosome 

What are the outermost cells in the seminiferous tubules that are involved in spermatogenesis called?

Spermatogonia.

What results from the first meiotic division of a primary spermatocyte?

Two secondary spermatocytes.

How long does spermiogenesis approximately take?

24 days.

What is the structure of a mature Spermatozoon composed of and their respective regions?

A head (genetic region), midpiece (metabolic region), and tail (locomotion region)

At what age does spermatogenesis begin in males?

Around 14 years old (age of puberty)

What is the total time for the entire process from primary spermatocyte formation to the release of immature sperm?

64-74 days.

During spermiogenesis, what is happening to the spermatid?

It is transforming into a sperm.

How many days does spermatogenesis approx. take within the seminiferous tubules?  

50 days 

how many approx. days does spermiogenesis take within the lumen?

24 days 

What is the difference between spermatogenesis and spermiogenesis? (how long it takes, the process, location) 

spermatogenesis - takes 50 days; the process of a spermatogonia splitting into spermatids; from the basement membrane to start of lumen

spermiogenesis - takes 24 days; the process of a spermatid forming into a sperm cell; from the lumen which travels to epididymis 

What are two types of cells that are produced from the spermatogonia?

type A and B daughter cells 

What is the purpose of Type A daughter cells?

becomes the new spermatogonium

What types of cells are produced at the end of each phase (3) during spermatogenesis?

mitosis → primary spermatocytes
meiosis 1 → secondary spermatocytes
meiosis 2 → spermatids

what is the primary difference between the first and second meiotic divisions in spermatogenesis?

1st meiotic → diploid splits into haploid

2nd meiotic → sister chromatid pairs split

what characteristics change about spermatid to transform into a sperm cell within the lumen of seminiferous tubules?

• nucleus condenses into a head

• acrosome forms and contains enzymes to penetrate through ovum

• body elongates - cytoplasm wraps mitochondria to form midpiece

• centrioles elongates to form the tail/flagellum

• excess cytoplasmic baggage sheds