- Structures and Functions of the Reproductive System (Male and Female)
- Structure of the Gametes (Sperm and Ovum)
- Differences Between Male and Female Reproductive Organs
Most multicellular animals and plants undergo a complex form of sexual reproduction in which especially differentiated male and female reproductive cells (gametes) unite to form a single cell, known as a zygote, which later undergoes successive divisions to form a new organism. The process takes place with the help of the system known as the reproductive system. This system can be divided into
- male reproductive system and
- female reproductive system.
STRUCTURE AND FUNCTIONS OF MALE REPRODUCTION SYSTEM IN MAMMALS
|Testis||Oval shaped, found in scrotal sacs in pairs outside the body to enjoy cooler temperature.||production of spermsproduction of male sex hormones (testosterone)development of secondary sexual character in male .|
|Seminiferous tubules||Found within the testis, composed of a mass of sperm producing tubes.||Site of sperm production|
|Epididymis||Found outside the testis as a long coiled tube.||Collect and stores sperm temporary till maturity.|
|Vas deferens (sperm duct)||A narrow tube which leads from epididymis to the seminal vesicles.||Conduction of sperm from epididymis to seminal vesicle.|
|Seminal vesicle||A small sac at the back of vas deferens.||Stores sperm till ejaculation.Secretes part of the seminal fluid. NOTE; Seminal fluid contains fructose which provides energy for the sperms.|
|Prostrate gland||Connected to the urethra through many tubules||Secretion of seminal fluid.|
|Cowper’s gland||Located very close to the prostrate gland.||Secretes a part of the seminal fluid which raises the acidic ph of the female reproductive medium which otherwise can kill the sperm.|
|Urethra||A narrow tube which passes through the penis.||Aids the passage of sperm into the vagina of the female animal and also passage of urine out of the body hence it is called urinogenital opening.|
|Penis||Contains tissues which makes it turgid (erect when filled) with blood||Helps to introduce sperm into the vagina of the female animal and also passage of urine.|
- Outline five structural parts of the male reproductive system and their functions
STRUCTURES AND FUNCTIONS OF THE FEMALE REPRODUCTIVE SYSTEM
|1||Ovaries||Found on each side of the vertebra column (two in every woman)||– Produce eggs (ova) – produces female sex hormone (oestrogen and progesterone) – Development of secondary sexual characters in female.|
|2||Oviduct (fallopian tube)||A long narrow tube funnel opening which receives eggs released by the ovary and it is a linkage between ovary and uterus.||-Fertilization takes place in the oviduct – Allows the passage of egg from ovary to the uterus|
|3.||Uterus||A muscular organ which is a cavity for development of the zygote into a baby.||– Site of embryo development from implantation till birth|
|4.||Vagina||A muscular tube leading from the uterus to the outside of the body.||– It receives sperms from penis during intercourse -Allows the passage of foetus during birth|
|5||Cervix||A ring of muscles with tiny opening that closes the lower end of the uterus where it joins the vagina.||-Controls the opening and closing of the vagina especially during birth.|
|6||Vulva||Refers to all external parts of the female reproductive organ||– Allows the passage of the penis into the vagina during intercourse. – permits passage of foetus during birth.|
|7||Clitoris||A small sensitive organ which correspond to the male penis. It is erectile and becomes stiff when stimulated due to blood inflow||Helps to stimulate female during sexual intercourse(experience orgasm)|
- State five structural differences between male reproductive system and female reproductive system.
- Describe the organs in the female reproductive system.
STRUCTURE OF MAMMALIAN GAMETES
Gamete is a mature sexual reproductive cell having a single set of unpaired chromosome. It can be male or female gamete. They are formed in the gonads (testis on ovaries) through a process called gametogenesis.
This is called sperm (or spermatozoa) and produced in the male gonads (testis) by a process called spermatogenesis. It is microscopic and unicellular in nature. Usually smaller and more elongated than the egg; about 0.05 mm (0.005 cm) long.
Spermatozoon consists of the following parts:
- Acrosome: It can be found at the upper part of the head, containing lytic enzymes used to dissolve egg membrane to enhance penetration during fertilization.
- Middle piece: It contains mitochondria for the generation of energy used by the sperm for swimming towards the egg.
- Flagellum: The long whip-like tail for propelling the sperm cell
- Nucleus: It can be found in the head of the sperm cell containing genetic materials (DNA-deoxyribonucleic acid) which fuses with the nucleus of the ovum at
This is called egg (ovum) and is produced in the female gonad (ovary) by a process called oogenesis. This is larger than sperm, about 0.1mm in diameter.
Each ovum is made up of the following
- A central Nucleus: It contains the chromosomes which carry the genes.
- Granules and yolk droplets: A source of nourishment for the embryo at the early stage of development.
- Plasma membrane: It surrounds the cytoplasm.
- Outer vitelline membrane and jelly coat of glycoprotein.
Note: The nuclei of the sperm and ovum contains chromosome which carries the gene that are responsible for transmission of characters from parents to offspring.
- What is reproduction?
- Draw a well labeled diagram of the male reproductive organ in mammals.
- List five structural parts of the female reproductive organ in mammals and state their functions.
- State five distinct differences between the male and female reproductive organs in mammals
- Differentiate between the male and the female gametes in mammals.
College Biology, chapter 16, pages 292-324
- The following are female sex hormone except A. oestrogen B. progesterone C. testosterone D. oxytocin
- The site of production of sperm is A. epididymis B. seminiferous tubules C. seminal vesicle D. penis
- Fertilization takes piece in the A. uterus B. vagina C. oviduct D. vulva
- ____ parts of the male gamete dissolve the egg membrane to enhance penetration A. nucleus B. acrosome C. flagellum D. vitelline membrane
- The process by which the male and the female gamete are formed in the gonads is referred to as ____ and _____
- Draw a well labeled diagram of the sperm cell and state the functions of the labeled parts.
- Differentiate between sexual and asexual reproduction