Download Cells and Chromosomes Note Sheet

Cells and Chromosomes Notesheet
Name_____________________________
 What is A Chromosome?
o Half of your chromosomes come ______________________. The other half
__________________________.
o ____________________ cells of the body have full sets of paired chromosomes.
o Label the diagram above with the following parts: Centromere, Gene, Sister
Chromatid
o A single chromosome looks like ______________________________________.
o A chromosome is made up of ________________. A _______________ is a
section of the chromosome that provides instructions for a single trait in the
organism.
o When the chromosome is duplicated itself, the copies are held together at the
______________________________. Each copy is called a
______________________ ________________________________.
 How Many Chromosomes Do I Have?
o Humans have ________ chromosomes:
 _____ of them do NOT determine the gender of the individual. These are
called ______________________________.
 _____ of them do determine the gender of the individual. These are called
___________________________________.
 In humans, the sex chromosomes are either _____ or _____.
 If you are a male, you have ______ sex chromosomes.
 If you are a female, you have _______ sex chromosomes.
o One can look at all the chromosomes in a cell by taking a picture of them. This
picture of the chromosomes is called a ____________________. The picture
usually pairs them up and arranges the pairs from the _____________________
pair to the ________________________ pair for autosomal chromosomes.
o In each chromosome pair, one chromosome comes from the _________________,
while the other comes from the _____________________.
o A pair of common chromosomes that code for the same genes are called
_____________________________ chromosomes.
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The picture above is of a karyotype from a human. What gender is this
individual? : ______________________
What do you notice is different about the X and Y chromosomes in this
picture? _________________________________________________
How many of the pairs are autosomal? ___________
How many of the pairs refer to sex chromosomes? ____________
 How are Sperm/Egg Cells Different From Other Cells In The Body
o Most cells in the body have a full set of chromosomes, which means they have
_______ chromosomes a piece.
o However, two types of cells in the body do NOT have this usual number. These
cells are either _____________ or ____________ cells. The name for any type
of sex cells is _________________________.
 Gametes have _______ chromosomes in humans.
 When the sperm and egg meet, this means the fertilized egg will have
_____ chromosomes.
o How do we refer to cells with different chromosome numbers?
 If a cell has the full amount of chromosomes in it (half from mother and half
from father), then it has a _______________________ number. This is
symbolized by the symbol of ________.
 If a cell has half amount of chromosomes in it (half from mother and half
from father), then it has a _______________________ number. This is
symbolized by the symbol of ________.
 A human cell has these numbers:
 Diploid number =
________
 Haploid number =
________
 2n number =
________
 n number =
________
 Number of chromosomes in autosomal cells = ________
 Number of chromosomes in gametes =
________