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Human Development: Fertilization to Implantation
Fertilization
The male gametes (
) fertilizes the female gamete (
) in the
: 23 chromosomes, very little food, long tail called flagellum
: 23 chromosomes, large because it contains lots of food (yolk)
Slides 1 and 2
1.
2.
Label your diagram (see board).
Draw a sperm cell (Slide 1).
3. Why do sperm cells have flagellum?
4. Why is the egg cell so much larger than the sperm cell?
5. Where did the egg cell originate from?
Draw an egg cell and one sperm cell (Slide 2).
.
Zygote forms
A zygote is a
.
The nucleus of the sperm
23 + 23 = 46
with the nucleus of the egg.
!
Occurs one hour after sperm entered the egg.
Once the zygote starts dividing into multiple cells, then it is called an
.
Slide 3
1. Label your diagram (see board).
2. Draw the fertilized egg (ZYGOTE). Label the two nuclei.
3. How many chromosomes are contained in the zygote?
4. Which parent, father or mother, contributed more chromosomes?
Morula forms
Once the embryo divides into multiple cells, it is called a
.
All the cells are the exact same size and shape because
has not yet begun.
Slide 6
1. Label your diagram (see board).
2. Draw the morula.
3. Circle the correct answer: Cell differentiation (has)(has not) began.
Blastocyst forms
Once the embryo divides into a ball of many different sized cells, it is called a
All the cells are the different sizes and shapes because
The embryo will now be
.
has begun.
in the wall of the uterus and develop.
Slide 7
1. Label your diagram (see board).
2. Draw the blastocyst. Draw an arrow to the hollow space within the blastocyst.
3. Why aren’t all the cells the same size?