Download 6.1 Chromosomes and Meiosis

Set
Cornell Notes onand
pg. Meiosis
6.1 up
Chromosomes
65
6.1 Chromosomes
and Meiosis
2.1 Atoms,
Ions,
and Molecules
•Topic: 6.1 Chromosomes
and Meiosis
•Essential Question:
1. Where are germ cells
located in the human
body?
2. Draw a double-bubble
map comparing and
contrasting autosomes
and sex chromosomes
1.
2.
Where are germ cells located in the
human body?
Draw a double-bubble map comparing
and contrasting autosomes and sex
chromosomes
Key Concept: Gametes have
half the number of
chromosomes that body cells
have
6.1 Chromosomes and Meiosis
KEY CONCEPT
Gametes have half the number of chromosomes
that body cells have.
6.1 Chromosomes and Meiosis
• Human body cells have 23
pairs of chromosomes and 46
total
– Each pair of chromosomes
is called Homologous pairs
and have copies of the
same genes
– In each pair, one
chromosome comes from
each parent.
*Homo= same
Mom Dad
6.1 Chromosomes and Meiosis
• You have two types of specialized cells:
Somatic cells
and
Germ cells
Will become…
6.1 Chromosomes and Meiosis
• Somatic cells- are body cells and make up
most of your body tissues and organs.
– Liver cells
– Lung cells
– Heart cells etc…
Red blood cells
skin cells
bone cells
intestinal cells
6.1 Chromosomes and Meiosis
Somatic (body) cells are Diploid (2n) cells have two copies
of every chromosome (23 from mom, 23 from dad) for a
total of 46 chromosomes
n
n
2n
*di= 2
6.1 Chromosomes and Meiosis
Germ cells- are the cells in your
reproductive organs
•located in the ovaries and
testes
•Develop into gametes
6.1 Chromosomes and Meiosis
Gametes are sex cells: egg and sperm
•Both have DNA that can be passed to offspring.
Egg
Sperm
6.1 Chromosomes and Meiosis
• Gametes are Haploid (n) cells have one copy of every
chromosome.
– Have 22 autosomes + 1 sex chromosome = 23
chromosomes each
23
23
6.1 Chromosomes and Meiosis
• You have two types of specialized cells:
Somatic cells
Germ cells
• Undergo mitosis
• Undergo meiosis
• body cells
• Cells in
reproductive organs
(ovaries/testies)
• Diploid
• 46 chromosomes
• Become gametes
(sperm/eggs)
• Identical to parent
cell
• Haploid
• 23 chromosomes
•
Each are Unique
6.1 Chromosomes and Meiosis
• You have two types of chromosomes:
Autosomes
and Sex Chromosomes
6.1 Chromosomes and Meiosis
•Chromosome
pairs 1-22 are
called
autosomes
•Contain genes
not directly
related to your
gender
6.1 Chromosomes and Meiosis
Pair #23=Sex chromosomes: X and Y
• determine gender
• Control the development of sexual
characteristics
XX= female
XY= male
XX
XY
6.1 Chromosomes and Meiosis
Points to Ponder
1.Where are germ cells located in
the human body (2 places)
2.Do you think that Y chromosomes
contain genes that are critical for
an organism’s survival? Explain.
6.1 Chromosomes and Meiosis
Points to Ponder
1. Where are germ cells located in the human body (2
places)
• In the reproductive organs: The ovaries in women
and the testes in men.
2. Do you think that Y chromosomes contain genes
that are critical for an organism’s survival? Explain.
• No, a Y chromosome is not necessary for survival.
Females do not have a Y chromosome, and they are
able to survive.
Set
Cornell Notes onand
pg.
6.1 up
Chromosomes
67
•Topic: 6.1 Mitosis vs.
Meiosis
•Essential Questions:
1. Does mitosis or
meiosis occur more
frequently in your
body? Explain.
2. Draw a double-bubble
map comparing and
contrasting mitosis
and meiosis (pg. 67)
Meiosis
6.1Ions,
Mitosis vs. Meiosis
2.1 Atoms,
and Molecules
1.
2.
Does mitosis or meiosis occur more
frequently in your body? Explain.
Draw a double-bubble map comparing
and contrasting mitosis and meiosis
6.1 Chromosomes and Meiosis
• Mitosis= makes more diploid cells.
• Produces genetically identical cells
• Results in diploid cells (46 chromosomes each)
• Takes place throughout an organism’s lifetime
• Involved in asexual reproduction
• Somatic (body) Cells
6.1 Chromosomes and Meiosis
*Draw on
pg. 74
DNA replicates
2 identical
daughter cells
6.1 Chromosomes and Meiosis
• Meiosis= makes haploid cells (23) from diploid germ
cells (46).
– produces gametes (sperm/eggs)
– Produces genetically unique cells
– Takes place only at certain times in an organism’s
life cycle
– Involved in sexual reproduction
– Germ cells
6.1 Chromosomes and Meiosis
(diploid- 46)
Germ cell
*Draw on
pg. 74
4 haploid (23)
unique daughter
cells
6.1 Chromosomes and Meiosis
Make a double-bubble Map comparing and contrasting mitosis
and meiosis on Pg. 67.
6.1 Chromosomes and Meiosis
Please open your book to page 172
• Please read the Genetic Data
information
• Interpret the second bar graph
and answer the 3 questions on the
bottom of pg. 74
• Title it “Genetic Data
Chromosome Interpretation”
6.1 Chromosomes and Meiosis
Diploid # of Chromosomes in Various
Organisms
Y- axis
Dependent
variable
10
20
40
40
49
55
210
X- axis
Independent variable
6.1 Chromosomes and Meiosis
1. King crab; fruit fly
2. No. A porpoise is much bigger than a king crab, and has far less
chromosomes. A potato is only 3 chromosomes off from human, and
far smaller.
3. Yes. Chromosomes need to be able to fit in the nucleus.
6.1 Chromosomes and Meiosis
Homework: Due by Friday11/08!!!!
Work on vocab on pg. 68-69 of INB
You need each vocab word- as well as a mini pic and description
6.1
• Sexual reproduction
• Fertilization
6.3
• Meiosis
• Traits
• Genetics
• Purebred
6.2
• Sperm
• Egg
6.4
• Gene
• Allele
• Homozygous
• Heterozygous
• Genome
• Genotype
• Phenotype
• Dominant
• Recessive