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DNA and Chromosomes
Prokaryote (vs) Eukaryote
Similarities between Prokaryotes and Eukaryotes
Prokaryotes and Eukaryotes both contain:
DNA
Ribosomes
Cell membrane (aka Plasma membrane)
Cytoplasm
Differences between Prokaryotes and Eukaryotes
Prokaryotes:
No nucleus
DNA is circular in the cytoplasm
No membrane bound organelles
Eukaryotes:
DNA inside nucleus
Contain membrane bound organelles
ReproductionReproduction is the process by which an organism produces others of the same kind.
Asexual ReproductionNew organisms are
made from only one parent.
The new organism is identical to the parent.
Types of Asexual ReproductionBinary Fission
Done by bacteria
Types of Asexual ReproductionBudding
Done by Bacteria, fungi, jellyfish and sea anemones
Types of Asexual Reproduction
Regeneration Done by some reptiles and amphibians
Types of Asexual Reproduction
Mitosis Done by all eukaryotic organisms
Binary Fission❑ The cell grows to a certain size
❑ Begin to replicate, their DNA once they have grown to a certain size.
❑ When DNA replication is complete,the cells divide through a processknown as binary fission.
❑ Binary fission is a form of asexual reproduction during which two genetically identical cells are produced.
Budding
Small outgrowth called a bud forms from the parent cell.
DNA is replicated
This bud continues to increase in size and becomes and independent organism from the parent
Regeneration
Process by which some organisms replace or restore lost body parts.
Sexual ReproductionRequires a sperm cell and an egg cell.
Requires two organisms.
FertilizationWhen a sperm joins with an egg, and a zygote forms.
Zygote- Made of one cell that forms a new organism.
Which of the following is incorrect
regarding prokaryotes?
A. Have a nucleus
B. Do not contain organelles
C. Do have a cell wall
D. Do contain DNA
How are sexual reproduction and asexual reproduction different from each other?
A. sexual reproduction requires two parents and asexual reproduction requires only one parent
B. asexual reproduction requires two parents and sexual reproduction requires only one parent
C. mutation rates are lower in sexual reproduction than in asexual reproduction
D. asexual reproduction occurs only in multicellular organisms.
7. Which type of reproduction leads to
increased genetic variation on a
population?
A. Budding
B. Asexual reproduction
C. Sexual reproduction
D. Mitosis
Eukaryotes Prokaryotes
Nucleus No Organelles
Ribosomes Cell Membrane
DNA No Nucleus
Organelles
Bacteria
Animals, Plants, Fungi and Protists
Cytoplasm
DNA:(Deoxyribonucleic Acid)
Chromosomes are made out of DNA.DNA looks like a double-helix, or a twisted ladder.DNA codes for the creation of proteins.
Structure of DNADNA is made up of
repeating series of nucleotides.
A nucleotide consists of:Sugar GroupPhosphate GroupNitrogen Base
Chromosome Structures
What is the role of chromosomes?
❑ Chromosomes carrythe genetic information that is passed on from one generation of cells tothe next.
❑ Every cell must copyits genetic information before cell division begins.
❑ Chromosomes make it possible to separate DNA precisely during cell division.
MITOSIS
Mitosis produces ONLY body cells.They are all identical to
each other.(AKA somatic cells!!)
All body cells contain 46 chromosomes
How do little elephants grow up to be BIG
elephants?
Why do our cuts heal?
Cell Division—Mitosis
Cell Division —process by which a cell divides into2 IDENTICAL daughter cells
• Why do cells need to divide?
1. Growth
2. Repair of damaged tissue
3.Replacement
2
Daughter
Cells
Understanding the Basics
• The original cell is called the parent cell
• 2 new cells are called daughter cells
• Each daughter cell is exactly like the parent cell • Same number of chromosomes
Parent cell
Mitosis: Forming Body Cells
Meiosis
Meiosis produces ONLY sperm and egg cells. (AKA gametes)
All sex cells contain 23 chromosomes(AKA gametes!!)
Homologous Chromosomes Code for the same gene in the
same region of the chromosome, but they are not the same. One is from mom and one from dad.
Sperm
23 Chromosomes
Egg
23 Chromosomes
Baby
46 Chromosomes
Meiosis: Forming Sex Cells
Each chromosome consists of 2 _____.
a. centrofibers
b. chromatids
c. daughter cells
d. centrioles
What structures that carry DNA called?
A) cyclins
B) chromatids
C) chromosomes
D) kinases
Which of the following forms sex cells?
A) mitosis
B) asexual reproduction
C) regeneration
D) meiosis
How many chromosomes do body cells
contain?
A) 23
B) 46
C) 96
D) 24