1. “I find the harder I work, the more luck I seem to have.”
12/2/2018
Title: Biology 12/6/06
Objectives:
To assess knowledge of chapter 5 and begin learning about cell division.
Class Topics
All chapter 5 corrections are to be handed in before the bell rings
Chapter 5 Test
Begin Chapter 6
“I find the harder I work, the more luck I seem to have.”
Thomas Jefferson
Sunday, December 02, :41 AM

2. Class Assignments Chapter 5 Test 12/6/06 Read 118-129 12/8/06
12/2/2018
Class Assignments
What
By When
Chapter 5 Test 12/6/06
Read /8/06
W.S /8/06
Due this class period
Due next class period
Due in the future

3. Grade Sheet 1A – SR p. 61 - 5 pts Measurement W.S. – 10 pts
12/2/2018
Grade Sheet
1A – SR p pts
Measurement W.S. – 10 pts
3A SR p. 42 – 6 pts
4A – SR p. 47 – 5 pts
2A – Measurement W.S. – 10 pts
SR p. 80 – 5 pts

4. 12/2/2018
Posttest Activities
Read

5. Chromosomes Made from DNA Formed from chromatin
12/2/2018
Chromosomes
Made from DNA
Genetic material that directs activities and determines characteristics
Formed from chromatin
Right before mitosis
Chromatin coils up into rods

6. Eukaryotic Cell Reproduction (Mitosis)
12/2/2018
Eukaryotic Cell Reproduction (Mitosis)
Each chromosome (at this point) is made up of 2 identical chromatids
Joined strands of identical duplicated genetic material
Joined at centromere
Chromatids separate and each cell has identical information
Formed in S phase of cell cycle
Chromosome Number in Various Organisms
& Chromosome Structure
From:
notebook/courses/guide/chromo.htm

7. From: http://www.accessexcellence.org/RC/VL/GG/nucleosome.html
12/2/2018
From:

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Sets of chromosomes
Each human somatic cell has 23 pairs of chromosomes (46 total)
Homologous chromosomes
Each pair is called homologous
Similar in size, shape and genetic content
Not identical!
One from each parent

10. Sets of chromosomes Somatic cells Gametes Fertilization Diploid (2n)
12/2/2018
Sets of chromosomes
Somatic cells
Diploid (2n)
2 sets of chromosomes (46 total)
Homologous pairs
Gametes
Haploid (n)
1 set of chromosomes (23 total)
Sperm and egg
If an organism has haploid number ___ of chromosomes, how many are in a diploid cell?
Fertilization
Two haploid gametes join to form a zygote (2n)
Fertilized egg

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12. Numbers of chromosomes
12/2/2018
Numbers of chromosomes
Karyotype
Table 1 (p. 121)

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14. “Geographer of the Male Genome”
12/2/2018
Chromosomes
23 homologous pairs
22 pairs of autosomes (44 total)
Numbered chromosomes
1 pair of sex chromosomes (2 total)
Contain genes to determine gender????
X chromosome – needed, many genes
Y chromosome – genes used to determine male gender
Male XY
Female XX
Father determines gender of child
Sperm contains X or Y chromosome
“Geographer of the Male Genome”

15. Changes in chromosome number
12/2/2018
Changes in chromosome number
Monosomy
Having 1 less chromosome (45)
Autosomes = lethal
Sex = XO – Turner syndrome
YO - lethal
Trisomy
Having 1 more chromosome (47)
Abnormalities occur
Trisomy 21 = Down syndrome
Caused by nondisjunction
failure of chromosomes to separate

16. Down Syndrome Occurs most often in “older” mothers Characteristics
12/2/2018
Down Syndrome
Occurs most often in “older” mothers
+37 years 1 in 290 births
+45 years 1 in 46 births
Characteristics
Short stature, round face, “slanted eyes”, varying degrees of mental capacity
Prenatal testing
Amniocentesis
Chorionic villi testing

17. From: http://www.criduchat.asn.au/criduchat/what.htm#Diagram%201
12/2/2018
Mutation (Handout)
Changes in chromosome structure
Deletion
Cri du chat syndrome
5p deletion
Translocation
14-21
Another cause of Down Syndrome
From:

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