BIOLOGY 1 Marks Question

In most of the aquatic algae and animals like earthworm, cockroach, insects, fishes and amphibians, gametic fusion (fusion of sperms and ova) takes place outside the body of female ie. in external medium like water hence it is said to be external fertilization.

(i) About 50 years.
(ii) At the age of 10 years.

Differences between menarch and menopause :

Menarch	Menopause
1. The first menstrual cycle or beginning of menstrual cycle in the life of a girl after onsetting puberty is called menarche	1. It is stoppage of menstrual cycle.
2. It begins at the age of 12-13 years.	2. It occurs at the age of 45-50 years.

The muscular and glandular layer of human uterus are as follows :
1. Epimatrium : It is made of external and visceral peretonium.
2. Myomatrium : It is highly muscular made by thick layer of nonstriated muscles.
3. Endomatrium : It is the innermost glandular layer. During menstrual cycle, cyclic changes occur in endomatrial layer and it is maintained by FSH, LH, estrogen and progeston hormone. 

Vas deferens in adult are internally slimmy and muscular which helps in conduction of sperms by peristalsis of its highly muscular coat but on replacing the Vas deferens by rubber’s tube after removal, sperm mvoement will not occur through rubber’s tube

Testis are extra-abdominal i.e. lie outside the abdominal cavity because normal development of sperms through spermatogenesis requires a temperature of 2-2.5ºC less than body temperature which is not possible in abdominal cavity.

The hormones secreted by testis in male control the secondary sexual control. If these hormones are injected into females, she develops secondary sexual characters of males i.e. beard and moustaches, coarse sound and this disorder is called virilism

Clitoris : It is a knob like structure which lies at the upper junction of the two labia minora above the urethral opening. It is highly sensitive due to presence of tactogranules. It is homologous to male penis. At the time of sexual intercourse it is helpful in transmitting stimulation waves in females.

On removing the epididymis, the maturation of sperms, their nourishment and temporary storage would not be possible, therefore sperms die and do not reach the vas deferens and no fertilization would be possible thereby.

The milk ejaculated for the first time from mother's breast after parturition for infant is called colostrum. It is slightly yellow, viscous and rich with IgA

The process of release of ovum as mature secondary oocyte by rupturing of graafian follicle into abdominal cavity under the influence of LH is called ovulation.

Trophoblast in human embryo peneterates the endometrium so that blastocyst could implant in endometrium.

Corpus luteum in human ovary secretes progestrone.

Lutenizing hormone (LH) induces the repturing of graafian follicle.

Foetal ejection reflex stimulates pituitary gland to release oxytocin for parturition.

Colostrum has IgA, which provides non-specific passive immunity against various diseases in newborn babies.

Blastocyst gets implanted into uterine wall of human female after 7 days of fertilization.

Inverted pear shaped.

Uterine wall is formed by three layers: (i) Perimetrium (outer layer), (ii) Myometrium (middle layer), (iii) Endometrium (inner layer).

The adipose tissue forms the mons pubis.

Clitoris.

Hymen

Bartholin glands secrete the colourless substance females during sexual excitement.

Relaxin hormone relax the pubic symphysis at the time of parturition.

There are 1-3 seminiferous tubules in each lobule of testis.

The storage and maturation of sperms occur in Epididymis.

Lactotropic Hormone (LTH) is responsible for milk synthesis after parturition.

Corpus luteum.

Haemochorial type or chorion type.

Pregnancy

(i) Peripheral cortex, (ii) Internal medulla.

Implantation

After birth of infant, the milk ejaculated from mother's breast for the first time is called colostrum which is light yellow, viscous and disease resistant.

Elephant-641 days, Dog-63 days, Cat-63 days.

Hyaluronidase secreted by acrosome in mammals helps in dissolving egg membranes.

Corpora cavernosa is found in penis.

The time period from fertilization to parturition of baby is called gestation period.

The process of ejaculation of semen by penis of male into female vagina during coitus is called insemination.

Menopause

Spermatids are non-motile, spherical haploid structure which undergo several changes in morphology, physiology and behaviour. The sum of all these changes by which non-motile spherical spermatid is metamorphosed into motile, spindle shaped sperms, is known as spermiogenesis.

Progestrone or estrogen.