Life Sciences P1

• Oviparous Aquatic Animals 


  Fertilization takes place externally in the water : Protected by a jelly - like layer. More gametes = More energy
• Oviparous terrestrial animals 


  Fertilization takes place internally and eggs are laid externally. Protection from a shell.
• Ovovivipary


  Eggs hatch inside the body and young are born alive few gametes = less energy
• Vivipary 


  Internal fertilization

  Embryo develops without a shell

  Few gametes =less energy
• Amniotic egg


  Adapted for life on land

  Embryo in egg with hard shell
• Precocial development 


  Young are fully developed and immediately mobile
• Altricial development 


  Young are not fully developed and arent mobile yet
• Parental care


  Keeping the young warm

  Feeding the young

  Protection from predators
• Function of testis

  Producing sperm and testosterone
• Function of the epididymis

  Stores sperm
• Vas deferens 


  Transports sperm from the epididymis >urethra
• Function of the Seminal vesicle

  Provides fructose for the sperm

  Lubricant
• Function of Prostate gland

  Secretes prostate fluid

  Propels semen >urethra during ejaculation.
• Functions of Cowper's gland

  Clears urine residue from the urethra.

  Lubricant for head of the penis
• Functions of the penis 


  Transfers sperm from Male>Female
• Function of the urethra 


  Transports urine and semen to the exterior
• Functions of ovaries 


  Produce and release ova

  Produce estrogen and progesterone
• Functions of the fallopian tubes

  Transport the ovum and developing zygote>the uterus

  Fertilization

  First divisions of zygote
• Functions of uterus lined by endometrium

  Protects and nourishes the developing embryo

  Implantation and development occurs

  Produces contractions to push the baby out during birth
• Cervix function


  Connects uterus to vagina
• Vagina function 


  Forms The birth canal

  Forms the pathway for the release of menstrual blood during menstruation
• Main changes in boys (puberty)

  • Increased muscle mass
  • A deeper voice
  • Growth of penis and testes
  • Production of sperm
  • More facial and body hair
• Main changes in girls (puberty)

  1. Hips widen
  2. Develops breast
  3. Menstruation (periods)
• Spermatogenesis 


  To produce male gametes
• Oogenesis 


  To produce female gametes
• Spermatogenesis 


  Under the influence of testosterone diploid cells in the seminiferous tubules of the testes undergo meiosis to form haploid cells.
• Functions of acrosome


  A sac at the front that digest the jelly layer of the ovum to penetrate the ovums memebranes
• Function of the middle portion(Sperm cell)

  Provides energy to the tail for locomotion
• Function of the tail (sperm cell)

  Whiplike movements to propel sperm through seminal fluid to swim to the ovum
• Oogenesis 


  Diploid cells in the ovary undergo mitosis to form numerous follicles at the beginning of puberty and under the influence of FSH.

  1/4 cells in the follicle enlarges and undergoes meiosis out of the 4 onle one survives to form a haploid ovum.
• Function of jelly layer (ovum)

  It provides protection to the early stages in development of the fertilized ovum
• Functions pf haploid nucleus (ovum)

  Contains 23 chromosomes
• Functions of the cytoplasm(ovum) 


  Provides nutrients to the fertilized ovum.
• Menstrual cycle

  1. Uterine
  2. Ovarian cycle
• Events in the ovarian cycle

  • Development of the Graafian follicle
  • Ovulation
  • Formation of the corpus luteum
• Events in the uterine cycle

  • Changes take place in the thickness of the endometrium
  • Menstruation
• Hormonal control of the menstrual cycle

  • Increase of Follicle Stimulating Hormone >Oestrogen>Luitenizing Hormone >Progesterone
• Negative Feedback

  • Increase in Oestrogen>no FSH(follicle stimulating hormone) >no development of follicles
  • Increase in progesterone and Oestrogen >no FSH AND LH >no ovulation
• Copulation Definition

  Sexual intercourse
• Fertilization process

  Haploid nucleus (sperm) >haploid nucleus (ovum)

  =diploid zygote