Chapter 4
Short
Question Answers – Reproduction
Q.1. What is
fission and in which type of animal the fission occur?
Ans. Fission is a type of asexual reproduction occurs in
circular living organisms. In this reproduction, the organism may be divided
into two or more than two parts.
Q.2. How many
types of fission are there?
Ans. There are two types of fission.
i. Binary Fission
ii. Multiple Fission
Q.3. What is
binary fission?
Ans. In this reproduction can be observe in protozoan and
bacteria. first the nucleus divides into daughter nuclei then self membranes
splits and form two daughter cell.
Q.4. What is
multiple fission?
Ans. It can be observe in parasitic protozoa. The nucleus
shows repeated divisions and then cell membrane is formed around each nucleus
in this many daughter cell are formed with in the parent cell. When parents
cell raptures, so theses daughter cell set free.
Q.5. Define
budding. Give examples.
Ans. This reproduction is found in yeasts hydra sponges
and other in vertebrates. in this process a small bud appears on the body which
gradually enlarged and after separation from the parents body transforms into
new individual.
Q.6. What is
the name of the asexual reproduction in which the egg cell forms new individual
without fertilization?
Ans. It is mode of reproduction in which development of
off spring occurs without fertilization and egg forms new individual.
Q.7. In which
animals parthenogenesis is an essential part of their life cycle?
Ans. In certain animals the parthenogenesis occurs
regularly constantly and naturally in their life cycle. Certain insects have no
sexual phase. They depend totally on the parthenogenesis for the self
production. The life cycle of certain insects includes two generation the
sexual generation and the parthenogenesis generation. Both of which alternate
to each other. In such cases diploid eggs produce females and unfertilized egg
produce males. E.g. bees, wasps, ticks and mites.
Q.8. What is
Cloning?
Ans. It is the modern technique of reproduction. In this
procedure, nucleus of ovum is replaced by diploid nucleus taken from the
somatic cell. After that ovum is implanted in the uterus of female. Where it
develops into an organism, which is exact copy of the parent who donated the
nucleus.
Q.9. What are twins and how many types of twins are there?
Ans. Twin are the two children which develop and born
together. Twins are of two types.
(i) IDENTICAL TWIN – These twins are of the alike sex
because they develop from one zygote hence they are called monozygotic twins.
They are same because they share some genes.
(ii) FRATERNAL TWINS –
These twins are developing from two separate ova, which are fertilized by two
separate sperms hence they are called dizygotic twins.
Q.10. What is
gametogenesis?
Ans. The process of formation of gametes is sex organs is
called gametogenesis.
Q.11. How
many types of gametogenesis are there?
Ans. Gametogenesis is of two types.
(i) SPERMATOGENESIS – It is the formation of sperm in the
testes. Germ cell after mitosis produces spermatogonia and then into primary
spermatocytes. Each primary spermatocyte in meiosis.
Produces two secondary sermatocytes which in meiosis.
Produce four spermatids, each ultimately develop into sperm.
(ii) OOGENESIS – It is the formation of eva in the
ovaries. Germ cell in ovary after mitosis produces oogania and the into primary
oocytes. Each primary oocyte in meiosis – I produces a secondary oocyte and a
smaller polar body. In meiosis – II secondary oocyte produces an ovum and a
polar body. Polar body produces from meiosis I produces two more polar bodies
in meiosis. In this way one ovum and three polar bodies are produced.
Q.12. What is
the difference between mating and fertilization?
Ans. MATING – Mating is the process in which male
and female contribute their ganetes for fertilization.
FERTILIZATION –
Fertilization is the process in which sperm and ovum after fusion produce
zygote.
Q.13. How
many types of fertilization are there?
Ans. There are two types of fertilization.
(i) EXTERNAL FERTILIZATION – When fusion between sperm and ovum
occurs outside the body of female is called external fertilization. For example
in frog, female eggs in water and male pour sperm on eggs.
(ii) INTERNAL FERTILIZATION – When fusion of male and female
gametes occurs inside the body of female is called internal fertilization. It
is the characteristics of all terrestrial animals.
Q.14. Give
the name of female reproductive organs.
Ans. Female reproductive system consists of following
organs
i. Ovaries
ii. Fallopian tubes
iii. Uterus
iv. Vagina
Q.15. What is
the shape of the ovaries and where they are located in the abdomen?
Ans. Ovaries are somewhat bean shaped bodies (Length =
4cm, Breadth = 2.5cm, Width = 1.5cm). The ovaries are situated on each side of
uterus, near the free end of fallopian tube, hanging by a ligament called
Mesovarium.
Q.16. Where
the development of ova takes place and how they are formed?
Ans. The surface layer of ovay is Germinal Epithelium,
where as interior is a mass of connective tissues called stroma. The ova begin
their development in the germinal epithelium even before birth. Ogonia in
epithelium divide by mitosis to produce about 2,00,000 primary oocytes. Each oocytes
is surrounded by a layer of stroma and forms a primary follicle. The primary
follicles remain dormant till puberty.
Q.17. What
are fallopian tubes are what are their functions?
Ans. They are also called oviduers. Each fallopian tube is
connected with uterus on one side and forms funnel shaped opening around ovary.
These tubes have cilia, movement of cilia together with the peristaltie
movement of smooth muscles propel the ova towards uterus. Fertilization occurs
in fallopian tube.
Q.18. What is
uterus and what is its function? Describe its histological structure?
Ans. It is pear shaped organ about the size of fist.
Uterus has three layers, perimetrium, myometrium and endometrium. Endometrium
is lined with, thick and glandular, epithelium which under the influence of
hormones thickness and shads in the absence of fertilization. Uterus is the
side of development of ambryo till birth. Uterus opens into vagina through a
muscular sphinter called cervix.
Q.19.
Describe the physiological significance of vagina.
Ans. It is muscle tube about 10cm long leading the cervix
to outside of the sperm body. This tube is the passage of sperm into the female
reproductive system.
Q.20. What is
menstrual cycle?
Ans. The cyclic discharge of blood, mucus and certain other
substances from the uterus at an average interval of 28 days is called
menstrual cycle. It starts at the age of puberty (12 – 14 years) and ends at
the age of (45 – 55 years). The onset of cycle is called menarche while
stopping of it is menopause.
Q.21. How
many phases are there in menstrual cycle?
Ans. Menstrual cycle consists of following phases
i. Menstruation Phase
ii. Follicular Phase
iii. Ovulation Phase
iv. Luteal Phase
Q.22. What is
menstruation phase and when it begins? Describe?
Ans. In the absence of fertilization of ovum with sperm,
secretion of progesterone declines because corpus luteum is shrinking.
Endometrium cannot persist in the absence of progesterone and endometrium is
striped off, discharge of blood, mucus and tissues remains continue for next 4
– 5 days through vagina.
Q.23. What is follicular phase? Which hormone initiates
the development of follicle in ovary?
Ans. The phase starts after the completion of the other
menstrual cycle. In this phase pituitary gland secrets a hormone, follicles,
stimulating soil, hormone (F.S.H) which initiate the development in primary
follicles of ovary.
Q.24. What is
graffian follicle and what is its function?
Ans. The walls of follicles become thicker and glandular
along with the maturation of ovum. The matured follicle is called graffian
follicle. These graffian follicle secrets, estrogen which via blood circulation
reaches to uterus and bring about rapid cell division in the walls of
endometrium and eventually becomes thicker and thicker. This process remains
continuous for 10 – 14 days.
Q.25. When
follicular is started and what are its main events?
Ans. Follicular phase is the phase starts after the
completion of the other menstrual cycle. In this phase pituitary gland secrets
a hormone follicles stimulating soil, hormone (F.S.H) which initiate the
development in primary follicles of ovary. The walls of follicles become
thicker and glandular along with the maturation of ovum. The matured follicle
is called graffian follicle. These Graffian follicle secrets, estrogen which
via blood circulation reaches to uterus and bring about rapid cell division in
the walls of endometrium and eventually it becomes thicker and thicker. This
process remains continuous for 10 – 14 days.
Q.26. What is
ovulation phase and when it begins?
Ans. Ovulation phase it occurs in the mid of cycle i.e.
14th day of cycle. The increased level of estrogen in blood declines the
secretion of follicle stimulating hormones (FSH) and a second hormone named
luteinizing hormone secrets from pituitary gland. This hormone helps us
rupturing of graffian follicle and ovum sets free from follicle. It is brief
phase of cycle.
Q.27. What do
you mean by Luteal phase and why it occurs?
Ans. Luteal phase mean while the ruptured graffian
follicle repairs itself by filling with yellow adipose tissues, it is called
corpus luteum, which begins to secrets progesterone which initiates the
development of endometrium and also increase vascularization in endomentrium.
In this way uterus is fully prepared for pregnancy.
Q.28. What
gonadotropin hormones and how many types of are there?
Ans. Those hormones of pituitary gland which influences
female reproductive cycle are collectively called gonadotropin. These hormones
are as follow
i. Follicle stimulating hormone
ii. Luteinizing hormone
iii. Luteotropic hormone (Prolactin hormone)
Q.29. What
are the endocrinological role of gonadotropic hormones in the control of ovary
physiology?
Ans. The endocrinological roles of each gonadotropic
hormone are given below.
(a). Follicle Stimulating Hormone (FSH) – This hormone
secretes from anterior lobe of pituitary gland. These hormones bring about the
development in primary follicles and convert them into graffian follicle.
(b). Luteinizing Hormone – This hormones also secrets from anterior lobe of
pituitary gland. This hormone help in rupturing of graffian follicle and
formation of corpus luteum.
(c) Luteotropic Hormone – This hormone also secrets from anterior lobe of
pituitary gland. This hormone initiates the production of milk from mammary
gland.
Q.30. What is
the physiological significance of ovary?
Ans. Role of
Ovary – Ovary is mainly
reproductive organ it has primary follicle which when starts development
secretes a hormone called estrogen, which is important for the development of
endometrium, after ovulation follicle forms corpus luteum which secretes
progesterone which finally prepares endometrium for pregnancy.
Q.31. Why
testes are present outside the abdomen between the thigas?
Ans. A pair of testes is presenting in sac of skin called
scrotum, which hangs between two thighs it is due to fact that sperm production
occurs at low temp.
Q.32. Where
spermatogenesis takes place?
Ans. Each testis contains 200 to 300 compartments. In each
compartment a mass of coiled semniferous tubule is packed. In these tubules
sperm are produced by the process of spermatogenesis. Sperm development takes
place in the walls of semniferous tubules and sperm discharge in the lumen of
tubule.
Q.33. Which
hormone is secreted from the testes and which is its function?
Ans. Testes also produce male sex hormone called
testosterone, which produces secondary male sexual characters.
Q.34. Where
sperm complete their maturation? Describe the structure in detail.
Ans. EPIDIDYMIS – Each epididymis is coiled tubule
about 20 feet long wrapped in a connective tissue and located on the top of
each testis. Sperm produces in each testis are transferred to epididymis, where
sperm complete their maturation.
Q.35. What is
vasa deference and how sperms are transferred to the urethra?
Ans. Vasa
Deference – The narrow tube of
each epididymis of merges into vas deference units with the ducts of seminal
verticals and forms ejaculatory duct which open into urethra. Vasa deference
store sperm for short period and transfer sperm to urethra by peristalsis.
Q.36. What is
urethra and how sperms are discharged into the vagina?
Ans. Urethra – Both the sperm and urine pass
through common tube called urethra. This urethra is present in a muscular
penis, which helps in discharge of sperm in vagina of female system.
Q.37. Which
gland is responsible for the nourishment and protection of sperms and how it
protect the sperms?
Ans. Seminal
Vesicles – Two seminal vesicles
contribute secretion rich in fructose, which nourishes sperm. Seminal vesicle
also secret fibrinogen which partially ‘gels’ the semen and helps in the
protection or sperm. Seminal vesicles are also connected with urethra by
ejaculatory ducts.
Q.38. What is
alternate name of cowper’s gland and what is its significance?
Ans. Cowper’s
Gland – These are two glands
which are also called bulbouretheral gland. These glands are located below the
prostate gland and secrets a lubricating fluid. This fluid has cleaning action
and helps in discharging of sperm from urethra.
Q.39. Which
organ is responsible for the neutralization acidic medium of vagina and how
sperms are free to move towards ovum?
Ans. Prostate
Gland – This located at the base
of bladder. Its secretes alkaline fluid which neutralizes acidic medium of
vagina. This fluid also has profibrinolysin which liquefies the gel of semen
and sperm are free to move towards ovum.
Q.40. What is
placenta and how it provides nourishment to the developing embryo from the
mother body?
Ans. Placenta – It is the connection of tissues of
mother and embryo. It is formed in endometrium. It has million of blood vessels
of mother embryo which provide medium for the exchange of different materials
between mother and embryo such as food, O2, CO2, and wastes. Placenta also
secrets progesterone which helps in pregnancy.
Q.41. What is
amniotic membrane and how embryo is protected from the physical shocks and
injuries
Ans. Amnion – It is an extra embryonic membrane
around the embryo of reptiles, birds and mammals, it has a cavity inside called
amniotic cavity, which contain amniotic fluid. This fluid protects the embryo
from external shocks and also provides watery environment to the embryo.
Q.42. What is
lactation? Define.
Ans. Lactation – After the birth of child, Prolactin
hormones secrets from pituitary gland which starts milk production from mammary
glands. This mechanism is called lactation. This milk contains nutrients and
anti bodies, which protects new born baby from disease.
Q.43. What is
umbilical cord and what is its function?
Ans. Umblical
Cord – It is rope like structure
formed by allantois. It connects the embryo to placenta. It contains blood
vessels which carry food and O2 from placenta to embryo and CO and other wastes
from embryo back to placenta.
Q.44. What is
test tube baby and how it is produced?
Ans. Test
Tube Babies – This technique is
applied on those couples which are failed to produce children. Sometimes sperm
and ova are failed to perform fertilization due to some barriers. So in the techniques
fertilization between sperm and ovum is performed in vitro. In this procedure
sperm is taken from testis of husband and ovum is taken from the ovary of wife.
Sperm and ovum are allowed to fuse together in test tube. After fertilization
zygote is implanted in the uterus of wife, where it develops into child.
Q.45. Which
bacteria are responsible for the spread of gonorrhea and what are its effects
on male and female?
Ans. This disease is caused by bacterium Neisseria
gonorrhoeae. This disease spread due to sexual contacts. In female it infects
oviducts and caused blockage of them and from female it is transmitted to her
child. In male bacterium cause infection in urinary system and pus formation.
Q.46. What is
syphilis and what are its pathological effects?
Ans. This disease is caused by bacterium. Treponema
pallidum. This bacterium not only damage reproductive organs but also effects
nervous system and skeletal system. This disease can be transferred infected
mother to her babies.
Q.47. How
blisters are produces around the external genital organs?
Ans. This disease is caused by virus herpes simplex. In
this disease painful blisters are produced around external genital organs. This
disease is transferred to new born baby.
Q.48. What is
AIDS?
Ans. This disease is caused by Human Immunodeficiency
Virus (HIV). This virus destroys the immune system of the person. Virus is
transferred to either partner through sexual contacts and from infected mother
to her baby.
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