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Module B
Unit 5
Cell Growth and Reproduction
Mr. Mitcheltree
DNA and Genetics
- The Cell and Inheritance
Gene = group of codons that code for a specific
protein
Allele = alternate form of a gene
A – dominant, a – recessive
both code for the same trait,
one from mom, one from dad
Homologous pair – one from each parent
# 1-22, 23rd is sex chromosomes
female – XX male - XY
Protein Synthesis
Transcription
DNA code to mRNA code – occurs in nucleus
Translation : Genetic Code to Protein
occurs in cytoplasm
Active Art build a Protien – reduce Power Point to Web
DNA Fantastic Song
Crash Course Biology : Transcription and Translation
Asexual Reproduction
• Parent cell produces offspring
genetically identical to parent.
• Offspring may look different
due to environment.
• In single-celled organisms
and simple animals called
binary fission or budding.
Binary Fission vs. Budding
-Cell Division
-S Phase of the Cell Cycle
Crash Course Biology:
DNA
upstream
5’ – 3’
3’ – 5’
downstream
DNA Replication:
- The Cell and Inheritance
Gene = group of codons that code for a specific
protein (order of AA’s determines specific shape)
Allele = alternate form of a gene
A – dominant, a – recessive
both code for the same protein,
one from mom, one from dad
Homologous pair – one from each parent
# 1-22, 23rd is sex chromosomes
female – XX male - XY
IPMAT
Binary fission
vs.
Budding
S Phase – DNA as
Chromatin in Nucleus
•
Part of Interphase
•
DNA Replicates
•
Sister chromatids form during prophase and are attached at
centromere.
A
A
A
a
a
a
Centromere
- Cell Division
- Cell Division time of Liver cell
Example of body cells
that would divide faster?
Slower?
G2
G1
S
-Cell Cycle
IPMAT
Prophase
•
Nuclear Envelope Disappears
•
Chromosomes Appear, Centrioles and spindle forms
Metaphase
•
Chromosomes line up on equator.
•
Spindle fibers from centrioles move chromosomes.
Anaphase
•
Sister chromatids separate and are pulled to each pole by
spindle fibers.
Telophase
•
Cell begins to divide. (Cytokinesis)
•
Nuclear envelope reforms
•
Chromosomes back to chromatin.
Furrow of
Animal cell
Mitosis Rap
Cytokenesis of Plant Cell
Cellulose and lignin are laid down on each side of the cell plate forming
a new cell wall at the end of cytokenesis
Sperm
Pollen
Ovule
= male
Egg
Sexual reproduction
• 2 gametes “parents”
= female
- Many organisms produce both gametes (Ex: plants)
and sexually reproduce themselves
2n multicellular
organism
Meiosis
2n
4
n
Haploid Gametes 23 chromosomes
All X
fertilization
1 of each homolog
from each parent
= 23 pairs
Diploid 23 pairs = 46
Meiosis
2n
4
2n
Zygote
n
Haploid Gametes 23 chromosomes
1/2 X, 1/2 Y
Diploid 23 pairs = 46
Mitosis
All cells genetically
identical – somatic stem
cells specialize
Allele = alternate form of a gene A = dominant a = recessive
sex chromosomes – determine sex of the offspring
- XX = female
- XY = male
Meiosis
4
XX
X
XX
Gametes
Fertilization
Meiosis
XY
2
X
2
Y
Gametes
XY
Mitosis vs. Meiosis
Disjunction
Homologs separate and move randomly
- crossing over may occur
2 homologous chromosome
pairs carrying dominant and
recessive genes
A A a a
A a
Equator
AA a a
AA
aa
A A
B
b
b B
b
B
bbBB
b b
bb
Diploid “Parent” Cell
BB
What else could have happened?
a a
B B
Equator
A A
b b
a a
B
B
A
A
A
A
b
b
b
b
a
B
a
B
A
b
A
b
4 haploid gametes
What else could have these been?
a
a
a B
B
a
B
Meiosis Overview
B
Chromatids in a tetrad crossing over
– one cause of genetic change
- mutation and variation
Chiasma
Random movement during
disjunction and Crossing Over
•
Variation of offspring
•
In humans, 64 trillion combinations after fertilization
•
1 in every 1,200 to 1,500 bases different
•
You have 50 - 100 new mutations from your parents – most
neutral (silent)
Study Island
6a Cell Growth and Reproduction
6b DNA and Genetics
Crash Course Biology
DNA Structure and Replication
DNA, Hot Pockets, & The Longest Word Ever
Mitosis: Splitting Up is Complicated
Meiosis: Where the Sex Starts