Overview

• What does the HPG axis refer to?

  Hypothalamic-pituitary-gonadal axis
• What is the significance of genetic sex determination in mammals?

  It influences developing reproductive systems
• What are the major neuroendocrine regulations discussed in the material?

  Regulation of the hypothalamic-pituitary-gonadal axis
• What are the non-breeding functions mentioned in the study material?

  Meat production, milk, eggs, replacement stock
• What factors influence biological efficiency in domestic animals?

  Reproductive efficiency, lactation ability, growth
• What are the key components of reproductive efficiency?

  Conception rates, litter size, embryo loss
• What is the role of lactation ability in biological efficiency?

  It affects yield, quality, and duration
• What does the term 'replacement rate' refer to?

  Rate at which breeding stock is replaced
• What are the factors that can change biological efficiency?

  Breeding, nutrition, environment, health
• What is the basic reproductive process in domestic species?

  Sexual reproduction through internal fertilization
• What is the genetic basis of a novel individual formed during fertilization?

  Fusion of haploid genetic complements
• What is the significance of sexual reproduction in terms of genetic diversity?

  It improves diversity and fitness
• What are the two sexes in dioecious animals?

  Male and female
• What do male animals produce from their testes?

  Male gametes (spermatozoa)
• What do female animals produce from their ovaries?

  Female gametes (ova)
• What are primary sexual characteristics?

  Gonad and gamete types
• What are secondary sexual characteristics?

  Overall appearance and behavior
• How is sex determined in some reptiles and amphibians?

  After fertilization by environmental factors
• How is sex determined in mammals?

  At fertilization by genetic factors
• What is the genetic makeup of female mammals?

  XX
• What is the genetic makeup of male mammals?

  XY
• What is the basic pattern of development in mammals?

  Female by default
• What is the role of Testis Determining Factor (TDF)?

  It masculinizes embryonic tissues
• What is the SRY gene responsible for?

  Expression of TDF in males
• What are the two key cell types in the indeterminate gonad?

  Mesoderm and primordial germ cells
• What do primordial germ cells migrate to form?

  Genital ridge
• What are the two indeterminate tubular reproductive tracts?

  Wolfian (male) and Mullerian (female)
• What happens to the indifferent gonad before week 6 in humans?

  It remains indeterminate
• What are the three types of somatic cells in the indifferent gonad?

  Supporting, endocrine, and connective tissue cells
• What do Sertoli cells produce in males?

  Support for sperm development
• What do Leydig cells produce in males?

  Gonadal steroids (testosterone)
• What do thecal cells produce in females?

  Gonadal steroids (estrogen)
• What happens without TDF in mammals?

  The basic ovary forms and meiosis begins
• When do oocytes form in female humans?

  By week 12
• What happens with TDF in male development?

  Spermatogenic cords form and meiosis is inhibited
• What hormones are produced by foetal testes?

  Testosterone and Mullerian Inhibiting Factor
• What is freemartinism?

  Sharing of blood between male and female twins
• What is the consequence of freemartinism for female twins?

  90% are sterile
• What is the role of the pituitary gland in reproduction?

  It regulates gonadal function through hormones
• What do GnRH secreting neurons do?

  They extend axons to the pituitary stalk