Year 7 Reproduction PDF

Year 7 Reproduction  Humans reproduce using sperm and egg cells. Sperm cells and egg cells are also called gametes. These cells are ‘specialised’ cells because they are a bit different to many other types of cells.  The egg is a very large cell.  Sperm cells have tails for swimming  Ga...

Year 7 Reproduction  Humans reproduce using sperm and egg cells. Sperm cells and egg cells are also called gametes. These cells are ‘specialised’ cells because they are a bit different to many other types of cells.  The egg is a very large cell.  Sperm cells have tails for swimming  Gametes are also unusual (compared to all the other cells in our body) because they have half of the normal amount of DNA  Gametes are produced in ovaries and testes- the primary sexual organs. A system of tubes and glands help in their storage and transfer. These make up the secondary sexual organs.  The sperm cell carries genetic information (DNA) from the father. The egg cell carries genetic information (DNA) from the mother.  Reproduction involves the DNA from the mother and father coming together. Many sperm swim to the egg and one sperm will enter the egg. The two half sets of genetic information then combine to make a complete set, capable of making a new human being  Male reproductive organs Stop and think: Can you name any of the male reproductive organs used to make, store or deliver sperm to the woman?  We will learn the names of the key parts and be able to identify them in front and side view pictures  Male Reproductive Structures For getting rid of urine: Bladder, Urethra, Sperm duct Where sperm is made: Testis For delivering sperm to the female: Penis, Erectile tissue, Foreskin, Sperm duct, Urethra  Let’s look at different pictures to practice learning the names of the key parts:  Male Reproductive Structures Now try and label this picture with a front and side view of the male reproductive system…. Label your diagram using the following words Bladder Testes Sperm duct Scrotum Penis Anus Seminal vesicle Prostate gland Urethra Answers  What does each part do?  Male Reproductive Structures Bladder- stores urine. Testis- male reproductive gland producing sperm. The hormone testosterone is also produced here. Sperm duct- tube that carries the sperm from the testis to the urethra. Scrotum- external sac containing testicles in mammals. Penis- the external male sex organ which is used during sexual intercourse to deposit sperm into the woman. It is also used to convey urine outside the body. Urethra- duct taking urine from bladder; in males it also carries the semen through the penis. Seminal vesicle and prostate gland- glands which make the liquid part of semen.  Male Reproductive Structures ____________- stores urine. ____________- male reproductive gland producing sperm. The hormone testosterone is also produced here. ____________- tube that carries the sperm from the testis to the urethra. ____________- external sac containing testicles in mammals. ____________- the external male sex organ which is used during sexual intercourse to deposit sperm into the woman. It is also used to convey urine outside the body. ____________- duct taking urine from bladder; in males it also carries the semen through the penis. __________ _________ and __________ _________ glands which make the liquid part of semen.  Male Reproductive Structures Bladder- stores urine. Testis- male reproductive gland producing sperm. The hormone testosterone is also produced here. Sperm duct- tube that carries the sperm from the testis to the urethra. Scrotum- external sac containing testicles in mammals. Penis- the external male sex organ which is used during sexual intercourse to deposit sperm into the woman. It is also used to convey urine outside the body. Urethra- duct taking urine from bladder; in males it also carries the semen through the penis. Seminal vesicle and prostate gland- glands which make the liquid part of semen.  Do you know the names of any female reproductive organs?  Which organs… Make the egg: ? Move the egg: ? Receive sperm: ? ‘Incubate’ a fertilised egg: ?  Which organs? Make the egg: ovary Move the egg: oviduct / fallopian tube Receive sperm: vagina ‘Incubate’ a fertilised egg: uterus  The ovary is lined with tiny ‘hairs’ called cilia, these waft the egg along the oviduct to the uterus after it has been realised from the ovary Female Reproductive Structures Now try and label this picture with a front and side view of the female reproductive system…. Label your diagram with these words: Ovary Oviduct / fallopian tube Uterus Cervix Vagina Bladder Urethra Anus Vulva Clitoris Answers  What does each part do? Female Reproductive Structures Ovary- found in plants and animals. The reproductive organ in which female gametes (eggs) are produced. Site of oestrogen production. Oviduct- a muscular tube lined with cilia move the egg. Where fertilisation occurs. Also called the fallopian tube. Uterus- in female mammals this is the organ in which the embryo implants, develops into a fetus and is nourished before birth. Cervix- the neck of the uterus just above the vagina Vagina- where the penis is placed during sexual intercourse and where semen is deposited, where the baby leaves the woman during birth. Bladder- stores urine Urethra- duct taking urine from bladder  Female Reproductive Structures _________- found in plants and animals. The reproductive organ in which female gametes (eggs) are produced. Site of oestrogen production. _________- a muscular tube lined with cilia move the egg. Where fertilisation occurs. Also called the fallopian tube. _________- in female mammals this is the organ in which the embryo implants, develops into a fetus and is nourished before birth. _________- the neck of the uterus just above the vagina _________- where the penis is placed during sexual intercourse and where semen is deposited, where the baby leaves the woman during birth. ________- stores urine ________- duct taking urine from bladder Female Reproductive Structures Ovary- found in plants and animals. The reproductive organ in which female gametes (eggs) are produced. Site of oestrogen production. Oviduct- a muscular tube lined with cilia move the egg. Where fertilisation occurs. Also called the fallopian tube. Uterus- in female mammals this is the organ in which the embryo implants, develops into a fetus and is nourished before birth. Cervix- the neck of the uterus just above the vagina Vagina- where the penis is placed during sexual intercourse and where semen is deposited, where the baby leaves the woman during birth. Bladder- stores urine Urethra- duct taking urine from bladder  Reproductive anatomy in other animals  Cloaca The Cloaca is a common chamber and outlet into which the intestinal, urinary, and genital tracts open. It is present in amphibians, reptiles, birds, and monotremes. A cloaca is not present in placental mammals or in most bony fishes. https://www.britannica.com/science/cloaca  Reptile reproduction Most reptiles reproduce sexually and have internal fertilisation. Males have a penis that passes sperm from their cloaca to the cloaca of a female. Fertilisation occurs within the cloaca, and fertilized eggs leave the female’s body through the opening in the cloaca. In a minority of species, the eggs are retained inside the female’s body until they hatch through the cloaca opening.  Birds Birds have a system which they have inherited from their reptilian ancestors, in which faeces, urine, eggs and sperm are all ejected through a single orifice, called the cloaca or vent. In 97 per cent of bird species, the males lack something possessed by almost all of their mammalian counterparts: a penis. This inevitably means that sperm cannot be deposited within the body of a female. Instead, when a male bird mounts a female, sperm is transferred by what is known as a ‘cloacal kiss’, which may last only a few seconds. The female then draws the sperm up into her reproductive tract to fertilise her eggs.  Most birds mate by joining their cloacas in a “cloacal kiss”; muscular contractions transfer the sperm from the male to female.  Bird reproduction During mating, a male bird presses his cloaca against his mate’s cloaca and passes sperm from his cloaca to hers. After fertilization, eggs pass out of the female’s body, exiting through the opening in the cloaca. Cloacal kiss  The three per cent of bird species that do possess a penis – or more strictly, a phallus, because it evolved independently from the mammalian penis – includes most ducks, geese and ratites (ostriches, emus and relatives). The organ is stored internally within the cloaca when not in use and is not involved in urination, and is used only to deposit sperm closer to the site of fertilisation within the female’s body. Phalluses tend to be present in species in which there is intense competition between males over access to females. Male ducks are highly sexually aggressive and routinely attempt to penetrate unwilling females with their corkscrew-shaped phalluses. A female duck’s vagina is also corkscrew-shaped, but coils in the opposite direction to the phallus. This makes copulation without female cooperation far from easy, and is thought to be the result of an evolutionary arms race between aggressive males and females trying to exert control over who fathers their offspring