Topic H: Human Reproduction Flashcards
Define Sexual reproduction?
Always involves the fusion of two cells called gametes.
Define a-sexual reproduction?
offspring genetically same because they have the same DNA as parents.
Define hermaphrodite?
Organism that can produce both types of gamete.
Define Ovary?
Produces eggs, attached to back wall of the abdominal cavity blow the kidney.
define Vagina?
Muscular tube that opens to the outside.
Define Prostate gland?
opens into the urethra and produces an alkaline fluid which neutralizes urine.
Define Sperm duct?
from the testis, opens into urethra
Define Urethra?
passes down penis, both sperm and urine pass through it.
Define Epididymis?
leads to sperm duct
define testis?
bundle of sperm producing tubules which join and lead to the epidermis.
When is the Ova released?
An Ova is released each month form an overy in the menstrual cycle.
Two ways in which the Ova is moved?
-Muscles expanding and contracting -Wafted along by the Cilia.
When does fertilization occur?
fertilization occurs when an ova meets with a sperm during its journey along the oviduct and then fuse together.
What happens during fertilization?
Fertilization occurs when the nucleus from the sperm fuses with the nucleus from the ova
A fertilized egg is called an…
Zygote
What then happens after fertilization?
The zygote will travel towards the uterus. This journey will take approx 3 days, in that time the zygote will divide and grow by MITOSIS into a ball of 64 cells known as a BLASTOCYST.
what is the ball of 64 cells known as?
a Blastocyst
What happens on implantation?
The blastocyst will then embed itself in the endometrium or the lining of the uterus wall.
What happens after implantation?
after implantation the blastocyst will develop into a embryo and then on to a foetus.
What is the period of development in the uterus will known as?
Gestation
How long does does gestation last in humans?
40 weeks
What is the Placenta?
The Placenta is the organ that allows a consistent exchange of materials between the mother and the foetus. The placenta develops from the foetal tissues
the structure of the Placenta?
The Placenta contains blood vessels of the foetus and blood vessels of the foetus and blood vessels of the mother.the blood vessels run very close to each other but do not touch. this means that the foetus’s blood and the mothers blood are kept separate and do never mix.
How are substances moved from the mothers blood to the foetus blood and vice versa?
This in in the Placenta and is done by diffusion.
What are the essential substances the foetus needs for its development from its mother blood?
Glucose, oxygen(respiration) and amino acids. waste produced will pass back into the mothers blood and she will excrete these substances such a carbon dioxide.
What is amniotic fluid used for?
-It protects and cushions the foetus from bumps -It helps with development of the lungs -It helps provide a constant temperature -It helps the development of the muscles
What area does the foetus develop?
The foutes develops inside a sac known as the amniotic sac.
Where is Testosterone made?
Testes (under the influence of another hormone)
What is the role of Testosterone?
To trigger puberty in males which leads to sexual maturity.