MEIOSIS AND SEXUAL REPRODUCTION OF ANIMALS

Today in class we discussed how we are different in apperance and sometimes in structure from our parents. Yet at teh same time we look like both of our parents. We carry similar physical traits or even personalities as they do. The reason is we get genetic information form both parents. Each human being is made up of 46 chromosomes. 23 are from your mother, 23 aref rom your father. These specialized cells are called gametes. the male produces a gamete called sperm, while the feamle produces a gamete called an egg. When they meet they become fertilized and produces a zygote cell. This is the begining of life!

In class we discussed how a cell divides its 46 chromosomes into two diploid cells in meiosis I, and then in meiosis II it again changes it's arrangement to only have 23 chromosomes in each gamete. ( see text pg 48 -49 for further details). This was demonstrated with our handout on spermatogenesis, and oogenesis. Important material to note!

HOMEWORK:
Please read pg 46-50 on meiosis to clarify today's lesson form class.
Please read pg 51-59 on sexual reproduction in animals.
Complete the handout on sexual reproduction in animals from the text book.
Pages were labelled on handout.

Please take detail on the CYCLE of life. pg. 52.
This sequence is very, very important.

You will be asked about the following in tomorrows class, so make sure you are ready to be questioned.

General notes:
( please print off ta copy for yourself to have a copy for class!)

For sexual reproduction to be successful you need
a) Both male and femal gametes to meet at the same time, place, for fertilization to occur.
b) the zygote must recieve enough food, moisture, warmth, and protection to develop.

Fertilization only happens if a sperm meets and egg, of the same species.
a) A moist environment is needed so the egg and sperm do not dry out.
b) so that the sperm can swim.
c) to keep the egg cell membrane moist so sperm can penetrate it.

There are 2 types of fetrilization. External and Internal.
Please make sure you read the appropriate pages listed in home work (51-59)