Reproduction Y8 Flashcards
What is sexual reproduction?
When there are 2 parents, gametes and it creates genetic variation
What is a-sexual reproduction ?
Only 1 parent, no gametes, genetically identical to parent
What are gametes?
Sex cells that contain genetic information (DNA)of a parent
How many sperm are made per day?
Millions
How is the sperm specialised for its functions?(3)
-Flagellum for swimming
-lots of mitochondria for respiration to release energy
-nucleus has half the set of genetic material (half from father)
How is the egg specialised for its functions?(3)
-lots of mitochondria for respiration to release energy
-nucleus has half the set of genetic material from the mother
-jelly coat around egg that makes sure only one sperm can enter and fertilise the egg
What gamete:
-is larger
-moves the most
-has a larger food store
-released more
-egg is larger
-sperm moves more as it swims, egg doesn’t move much
-egg has large food store, sperm doesn’t have a store
-sperm, millions can be produced in a day, only 1 egg released per month
Fertilisation definition
Fertilisation is the process of the nuclei of a sperm and egg cell(male and female sex cells) fusing together
What is it called when the nuclei of a sperm and egg fuse together ? (When fertilised)
Zygote
What are the two types of fertilisation?
Internal and external
Example of internal fertilisation
Humans-
Example of external fertilisation
Fish-female lays eggs on ground then male fertilises them.
What is a zygote?
Early development of offspring/ when the nuclei of an egg and sperm fuse
Ovary(3)
-organ where eggs mature and are released
-produces oestrogen and progesterone (from puberty to menopause)
-females have 2
Fallopians tubes(2)(Oviduct)
-tube that transports egg from ovary to uterus(using small hairs)
-Fertilisation may occur here
Uterus(3)
-organ where developing baby grows
-has thick wall of muscle and elastic tissue
-inner lining grows and is released from puberty to menopause
Cervix(2)
-Ring of muscle at neck of uterus
-where baby comes out through during birth
Vagina(2)
-muscular tube that opens to the outside
-sometimes known as birth canal
Labia(1)
-fleshy lobes that protect the opening of the vagina
Clitoris(1)
Area very sensitive to stimulation
Testes(2)
-organ that produces sperm from puberty.
-also releases testosterone
Scrotum(2)
-pouch of skin which holds testes outside the body
-so they are at a suitable temperature
Epididymis (2)
-mass of coiled tubes
-transports sperm from testes
Sperm duct(1)
-tube that carries the sperm from the testes to the glands and urethra
Glands (2)
-opens into sperm duct and produces seminal fluid
-opens into urethra and produces alkaline fluid which neutralises urine.
Penis(3)
-Organ, which transport, semen and urine into the outside.
-contains spongy tissue which fails with blood when the organ is stimulated
-This makes the organ erect so that it can be placed inside the female
Urethra(2)
-Tube which passes through penis
-both semen and urine pass through it.
Foreskin(2)
-Area of skin which covers a sensitive tip of the penis
-can be removed during circumcision
What percentage of genetic information does the new baby contain?
50% of the mothers 50% of the fathers
Which process places millions of sperm in the female?
Sexual reproduction
What happens to all the other sperm when a sperm enters an egg?
Jelly coat on egg stops them entering the egg .They cannot enter the egg, so they die at exit the female.
Where is the female egg fertilised?
Usually in the oviduct
Definition of fertilisation
The nucleus of the male gamete joins with the nucleus of the female gamete. (Nucleus of egg joins nucleus of sperm)
What is it called when the first egg splits into more and more cells?
An embryo
Each month, what part of the woman releases an egg?
Ovaries
If an egg cell meets a sperm cell, what can happen?
Fertilisation
What does the embryo do into the lining of the uterus?
Implants
What does it mean when the embryo implants?
It buries itself into the lining of the uterus