Consider the following statements:
I: | The primary follicles present at birth carry primary oocytes arrested at meiosis I. |
II: | The secondary oocyte arrested at meiosis II is released at ovulation. |
III: | The second meiotic division is completed by the secondary oocyte just prior to the entry of the sperm into it. |
Which of the above statements are true?
1. | I and II only | 2. | I and III only |
3. | II and III only | 4. | I, II, and III |
The epithelial covering of the highly vascular embryonic placental villi, which invades the wall of the uterus to establish nutrient circulation between the embryo and the mother are:
1. | chorionic villi cells | 2. | cytotrophoblast cells |
3. | inner cell mass | 4. | syncytiotrophoblast cells |
The fluid-filled cavities near the embryonic ectoderm and the embryonic endoderm are respectively:
1. amniotic cavity, blastocele
2. amniotic cavity, yolk sac
3. blastocele, amniotic cavity
4. yolk sac, amniotic cavity
The epidermis and the dermis of the skin develops respectively from embryonic:
1. ectoderm, endoderm
2. ectoderm, mesoderm
3. endoderm, mesoderm
4. endoderm, ectoderm
Identify the organ system in humans that is derived from all the three embryonic germ layers:
1. cardiovascular system.
2. digestive system.
3. endocrine system.
4. muscular system.
Parturition involves a positive feedback between:
1. uterine contraction, estrogen
2. estrogen, progesterone
3. estrogen, oxytocin
4. uterine contraction, oxytocin
Lactation after child birth is possible due to decrease in the secretion of:
1. HCG
2. oxytocin
3. FSH and LH
4. estrogen and progesterone
The initial phase of the cortical reaction leads to:
1. slow block to polyspermy
2. fast block to polyspermy
3. formation of pronuclei
4. completion of acrosome reaction
Prolactin is secreted by:
1. hypothalamus
2. anterior pituitary
3. posterior pituitary
4. mammary glands
The first form of milk produced by the mammary glands of mammals immediately following delivery of the newborn is called:
1. | prolactin | 2. | progesterone |
3. | milk | 4. | colostrum |