Friday, May 5, 2017

CBSE Class 12 - Biology - Human Reproduction - Important Terms (#cbsenotes)

Human Reproduction

Important Terms
CBSE Class 12 - Biology 

Male Reproductive System
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Q1: Define Spermatogenesis.

Answer:  It is the process of production of sperms by immature male germ cells that begins at puberty (Production of sperm).

Q2: Define Spermiogenesis

Answer: It is the process of transformation of spermatids into sperm.

Q3: What is spermiation?

Answer: It is the release of sperms from seminiferous tubule.

Q4: Define Oogenesis

Answer: The process of formation of a mature female gamete initiated during embryonic development.

Q5 Define Ovulation.

Answer:  The process during which the Graafian follicle ruptures to release the secondary oocyte (ovum) from the ovary is called ovulation.

Q6: What is Menarche?

Answer:  The first menstruation that begins at puberty is called menarche. It is starting of the first menstrual flow in females.

Q7: What is a Menstrual cycle?

Answer: It is the cycle of events starting from one menstruation till the next one after every 28 / 29 days.

Q8: Define Menopause

Answer: It is the cessation of menstrual cycle around 50 years of age.

Q9: Define gastrulation

Answer:  It is a type of morphogenesis in which inner cell mass move into embryonic disk forming three germ layers i.e. ectoderm, mesoderm, and endoderm.

Q10: Define cleavage.

Answer: It is the mitotic division the zygote undergoes when it moves toward uterus and forms blastomeres.

Q11 What is Implantation?

Answer: It is embedding of the blastocyst in the endometrium of the uterus leads to pregnancy.

Q12 Define Parturition.

Answer: The vigorous contraction of the uterus at the end of pregnancy causing expulsion/delivery of the foetus (child birth)

Q13: What is Foetal ejection reflex?

Answer: These are the mild uterine contractions induced by the signals for parturition from the fully developed foetus and the placenta.

Q14 Define Lactation.

Answer:  The process by which the mammary gland start producing milk is called lactation.

Q15: Write full for of the following acronyms:

GnRH: Gonadotropin-releasing hormone
LH: Luteinising hormone
FSH: Follicle stimulating hormone
hCG: Human chorionic gonadotropin
hPL: Human placental lactogen

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