43 Reproduction Physiology
what hormones are produced by the follicles and the corpus luteum
Follicles: estrogen corpus luteum: secretes estrogen but mostly progesterone
what two factors allows gametes to be different from another causing great genetic variability?
1) crossing over 2) random alignment during meiosis I
diploid
2 sets of chromosomes
How many chromosomes do gametes contain?
23 chromosomes
what is the end product of meiosis?
4 haploid daughter cells
zygote
fertilized egg
Within each ovary, the immature ovum develops in a saclike structure called a __________.
follicle
Define gametogenesis
formation of gametes
Haploid
having a single set of unpaired chromosomes
what two hormones are responsible for stimulating sperm production
luteinizing hormone (LH) and follicle-stimulating hormone (FSH) 1) FSH enters testis & stimulates Sertoli cells to provide nourishment to sperm cells 2) LH stimulates Leydig cells to produce testosterone
what is the function of interstitial endocrine cells (Leydig cells) ?
make testosterone
Define synapsis
the fusion of chromosome pairs at the start of meiosis.
what is the activating and genetic region of the sperm?
the head
Define: meiosis
a type of cell division that results in four daughter cells each with half the number of chromosomes of the parent cell, as in the production of gametes and plant spores.
what part of the sperm contains enzymes involved in the penetration of the egg?
acrosome
in which location would you expect to see cells containing tetrads, closer to the spermatogonia or closer to the lumen?
closer to the spermatogonia
what extend inward from the periphery of the seminiferous tubule and provide nourishment of the spermatids as they begin their transformation into sperm?
sustentocyte or Sertoli cell
Would these cells be primary or secondary spermatocytes
Primary (2n) spermatocytes
what occurs in meiosis I in spermatogenesis?
Primary spermatocyte (2n) gives way to 2 secondary spermatocytes (n)
What are the differences between mitosis & meiosis
MITOSIS: growth repair development; diploid = diploid; samatic; divides into 2 daughter cells; clones of parents & each other; 2 divisions MEIOSIS: sexual reproduction diploid = haploid gametes 4 daughter cells all unique 1 division
Define oogenesis
production of female gametes
Define spermatogenesis
production of sperm