Name: ____________________________
DNA review:
1. In the picture to the right, identify a chromosome and a gene.
2. In the picture below identify a nucleotide by drawing a box around it.
3. DNA is found in which cell organelle?
a. cell membrane
b. nucleus
c. vacuole
d. lysosome
Cell Review:
1.
Circle all the terms that apply to a somatic cell
from the choices below.
A. Haploid
b. diploid
c. skin cell
d. sperm
e. egg
f. 1 set of chromosomes g. 2 sets of chromosomes
2.
Circle all the terms that apply to a gamete
from the choices below.
A. Haploid
b. diploid
c. skin cell
d. sperm
e. egg
f. 1 set of chromosomes g. 2 sets of chromosomes
Fertilization:
1.
the process of fertilization. There are NO WRONG ANSWERS!
Write down what you think happens during
_________________________________________________________________________________________________
_________________________________________________________________________________________________
2.
Draw a picture of the fertilization process that
we worked with using the sperm and egg models.
Fertilization Need to Know:
1.
______________________________________
____________________________________________________
2.
______________________________________
____________________________________________________
3.
______________________________________
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Fertilization Comparison: Humans vs Flies
The process of human fertilization requires a male and a female to have sex. When the male ejaculates he releases
sperm into the vagina of the woman. The sperm that are released are haploid gametes, which contain one set of 23
chromosomes. Inside of the woman is another gamete, the egg. Like the sperm, the egg is haploid and also contains one
set of 23 chromosomes. At some point one of the male sperm cells will find the female egg cell and penetrate the egg.
When the sperm has penetrated the egg it releases its chromosomes into the egg. At this point a zygote has been
created. A zygote contains two sets of chromosomes, one from the sperm of the father and one from the egg of the
mother. The zygote is diploid and contains a total of 46 chromosomes. This zygote now contains all of the DNA
necessary in order to multiply into enough cells for a complete human.
The process of fly fertilization also requires a male and female fly to have sex. Similar to humans, a male fly will ejaculate
sperm into a female fly. The sperm of fly are haploid, but contain only 4 chromosomes. The same is true of the haploid
female fly egg cells, they also are haploid and contain 4 chromosomes. When the sperm of the male fly meets the egg of
the female fly, fertilization occurs. The cell that results from fertilization is diploid and contains 8 chromosomes. This
new cell contains enough DNA for it to multiply into enough cells for a new, complete fly.
Main Idea: _______________________________________________________________________________________
Supporting Details:
1. __________________________________________________________________________________________
2. __________________________________________________________________________________________
3. __________________________________________________________________________________________
Comprehension Questions:
1. How is fertilization similar between humans and flies? ____________________________________________
_______________________________________________________________________________________________
2. How is fertilization different between humans and flies? ___________________________________________
________________________________________________________________________________________________
3. The sperm of a kangaroo has 6 chromosomes, how many chromosomes are there in a kangaroo egg? _______
4. How many sperm would be found in the cells of kangaroos that are NOT sperm or eggs? _________
5. Skin cells of polar bears contain 74 chromosomes, how many chromosomes are found in polar bear sperm? ____
6. The gametes of grape vines contain 40 chromosomes, how many chromosomes are found in grape somatic
cells? _____
7. The disease Down Syndrome is genetic and is caused when a baby is born with cells that contain 47
chromosomes. There are three copies of chromosome number 21 instead of two. Why do you think having an
extra chromosome causes problems