Mastering KCSE Biology with Comprehensive Topical Questions and Answers

Describe the role of hormones in the human menstrual cycle.

1/7/2020

K.C.S.E Biology Q & A - MODEL 2018PP2QN07

Describe the role of hormones in the human menstrual cycle.

answers

After/at the onset of menstruation, (the anterior lobe of) the pituitary gland; secretes follicle stimulating hormone (FSH); the FSH causes the Graafian follicle; to develop into the ovary; and stimulate the ovary tissues to secrete oestrogen hormone; Oestrogen brings about repair/healing of the endometrium/uterine wall; its concentration increases to a level which stimulates the (anterior) pituitary gland; to secrete lutenizing hormone (L.H.) and stops further secretion of FSH;
The L.H. stimulates the maturation of the Graafian follicle; LH also stimulates the Graafian follicle to release an ovum into the (funnel of the) fallopian tube/causes ovulation; it also stimulates the remains of the Graafian follicle to form a yellow body/corpus luteum (in the ovary;
The corpus luteum is stimulated by the L.H. to produce progesterone; Progesterone then stimulates the thickening of the endometrium/inner lining of the uterine wall; in readiness for implantation; as progesterone level increases, it inhibits (the pituitary gland) from secreting FSH; further increase in progesterone level inhibits the pituitary gland from secreting L.H. This causes the corpus Luteum to degenerate; this reduces the amount of progesterone; the sudden drop in secretion of progesterone causes the endometrium to slough off/menstruation occurs; and the cycle is repeated;

Comments

State three roles of auxins in a plant stem.

28/6/2020

Comments

K.C.S.E Biology Q & A - MODEL 2014PP1QN06

State three roles of auxins in a plant stem.

ANSWERS

Cell division;
Cell elongation:
Development of adventitious roots;
Formation of callus tissue:
Causes apical dominance;
Causes tropic responses.

Comments

K.C.S.E Biology Q & A - MODEL 2012PP1QN25

26/6/2020

Comments

K.C.S.E Biology Q & A - MODEL 2012PP1QN25

State the role of the following hormones in the life cycle of insects:
ecdysone hormone; .
juvenile hormone.

answers

Ecdysone causes metamorphosis; towards adult stage
Juvenile hormone maintains larval characteristics;

Comments

K.C.S.E Biology Q & A - MODEL 1997PP1QN08

14/6/2020

Comments

K.C.S.E Biology Q & A - MODEL 1997PP1QN08

A person was found to pass out large volumes of dilute urine frequently.
Name the
(a) Disease the person was suffering from
(b) Hormone that was deficient

ANSWERS

(a) Disease the person was suffering from
Diabetes inspidus ref. Diuresis/ water diabetes
(b) Hormone that was deficient
Antidiuretic hormone/ ADH/Vasopressin

Comments

K.C.S.E Biology Q & A - MODEL 1995PP1QN16

25/5/2020

Comments

(a) Describe how insect pollinated flowers are adapted to pollination
(b) Describe the role or each of the following hormones in the human menstrual cycle
(i) Oestrogen
(ii) Progesterone
(iii) Luteinising hormone ( 9 mks)

KNEC ANSWERS

(a)
(i) Large; brightly coloured corolla/ inflorescence/ florets/ bracts to attract Insect
(ii) Scented to attract insects
(iii) Have nectary guides/ nectarines/ that directs insects/ secret nectar to attract insects.
(iv) Pollen grains rough/ spikey/ sticky/ surface; to stick on insects body
(v) Special shaped corolla tube; to enable insects to land
(vi) Anthers are situated inside the flowers to ensure that they are in contact with the insect
(vii) Sticky stigma; for pollen to stick or to adhere

(b)
(i) Oestrogen
Repair/ heal endometrium/ wall of uterus; which is destroyed in menstruation
(ii) Progesterone
Stimulates the thickening of the uterus; increases the blood supply to the endometrium. Inhibits the production of follicle stimulating Hormone.
(iii) Luteinising hormone
Responsible for maturation of the graafian follicles/ causes ovulation/ stimulates corpus luteum; to secrete progesterone.

Comments

KCSE Biology Topical Questions and Answers | Atika School

Describe the role of hormones in the human menstrual cycle.

Describe the role of hormones in the human menstrual cycle.

State three roles of auxins in a plant stem.

State three roles of auxins in a plant stem.

K.C.S.E Biology Q & A - MODEL 2012PP1QN25

K.C.S.E Biology Q & A - MODEL 2012PP1QN25

K.C.S.E Biology Q & A - MODEL 1997PP1QN08

K.C.S.E Biology Q & A - MODEL 1997PP1QN08

K.C.S.E Biology Q & A - MODEL 1995PP1QN16

(a) Describe how insect pollinated flowers are adapted to pollination
(b) Describe the role or each of the following hormones in the human menstrual cycle
(i) Oestrogen
(ii) Progesterone
(iii) Luteinising hormone ( 9 mks)

TOPICS

Form 2

Form 3

Form 4

Archives

Categories

KCSE Biology Topical Questions and Answers | Atika School

Describe the role of hormones in the human menstrual cycle.

Describe the role of hormones in the human menstrual cycle.

State three roles of auxins in a plant stem.

State three roles of auxins in a plant stem.

K.C.S.E Biology Q & A - MODEL 2012PP1QN25

K.C.S.E Biology Q & A - MODEL 2012PP1QN25

K.C.S.E Biology Q & A - MODEL 1997PP1QN08

K.C.S.E Biology Q & A - MODEL 1997PP1QN08

K.C.S.E Biology Q & A - MODEL 1995PP1QN16

​(a) Describe how insect pollinated flowers are adapted to pollination(b) Describe the role or each of the following hormones in the human menstrual cycle(i) Oestrogen(ii) Progesterone(iii) Luteinising hormone ( 9 mks)

TOPICS

Form 2

Form 3

Form 4

Archives

Categories

(a) Describe how insect pollinated flowers are adapted to pollination
(b) Describe the role or each of the following hormones in the human menstrual cycle
(i) Oestrogen
(ii) Progesterone
(iii) Luteinising hormone ( 9 mks)