Answers to control of mammalian oestrous 1. (a) Around twenty-four hour percentage point 2 / sidereal twenty-four hours 20; Coincides with LH / follicle-stimulating endocrine gland peak;2 (b) (No) / (no mark for no) progesterone levels fail;1 [3] 2. (a) follicle-stimulating hormone stimulates rebelth of a follicle; Developing follicle produces estrogen; (FSH) and LH take aim about ovulation / oestrus; LH stimulates constitution of corpus luteum; LH stimulates production of progesterone; Fall in LH / FSH means oestrogen production no longer bear upon;5 max (b) (i) Progesterone inhibits FSH; No follicles discover; (ii) Causes rise in FSH / inhibition of FSH take away; Stimulates follicle development;4 [9] 3. (a) (i) LH peaks/is high (on twenty-four hourstime 12):1 (ii) spermatozoon suffer survive up to 2-7 age; bombard can survive a few(prenominal) hours/ up to 3 days; OR General idea of short-lived gametes (e.g. a few days) = max.
1 mark2 (b) (i)1nhibits (release of) FSH; Follicle does not develop/mature/ wrick/prevent ovulation/ FSH causes follicles to develop; (Allow: ovum not produced) [Reject: attribute to follicle production]2 (ii)Progesterone;1 ! [6] 4. (a)Any two from: Follicle diameter/ surface drops all at once on day 21/at this snip; crank/ovum/oocyte released from follicle (causes size decrease); Corpus luteum formed on day 21/at this time;max 2 [Note: focal ratio limit 1 mark if no time given] (b)On day 18 oestrogen peaks/at 6.0/rises to highest value; = 1 day before start of oestrus; 2 (c)Size and concentration body politic a positive correlation/described; Corpus luteum produces progesterone; 2 (d)Any six from: 1...If you want to get a full essay, order it on our website:
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