Genetics Flashcards
What is asexual reproduction?
reproduction involving one parent which gives rise to genetically IDENTICAL offspring
What is the importance of cell division?
- Growth of multicellular organisms
- Repair (healing)
- Replacing worn out cells
What is the cell cycle?
sequence of activities that occurs from one cell division to the next.
What is Binary Fission?
Splitting into two. Circular DNA chromosome is replicated, attaches to the cell membrane, are pulled apart as the cell splits in two. It results in two cells with an equal division of DNA.
What uses Binary Fission?
Prokaryotes
What is the cell cycle in Eukaryotes?
- Interphase
2. Miotic Division Phase
What are the stages of interphase?
- G1 Phase: period of growth and normal metabolic activity. Proteins are synthesized BUT NOT REPLICATED.
S: DNA is duplicated.
G2: Organelles replicate and preparations are made for the separation of the duplicated DNA. Chromosomes BEGIN to condense.
What are the states of Mitotic Division Phase?
- Mitosis: Division of the nucleus
2: Cytoknesis: Divison of cellular material.
What are the stages of Mitosis?
- Prophase
- Metaphase
- Anaphase
- Telophase
What happens during interphase in Mitosis?
-cell prepares for division by duplicating chromosomes
-chromosomal material is organized into CHROMATIN.
-CHROMATIN is replicated and condensed to become CHROMATID.
-2 CHROMATIDS join in the middle at the CENTROMERE and become SISTER CHROMATIDS (2 replicas of a single chromosome).
(2 Sister Chromatids joined at the centromere become CHROMSOMES)
What happens during Prophase in Mitosis?
Chromosomes shorten and thicken (become visible)
CENTRIOLES move to opposite poles of the cell and attach to SPINDLE FIBERS. (Centrioles ARE NOT IN PLANT CELLS)
Nuclear membrane dissolves.
What happens during Metaphase in Mitosis?
Chromosomes composed of 2 sister chromatids align along the equator.
What happens during Anaphase in Mitosis?
Centromeres divide and sister chromids move to opposite poles.The same number of individual sister chromatids (now called daughter cells) will be found at each pole.
What happens during Telophase in Mitosis?
Chromosomes uncoil and become Chromatin again.Spindle fibers dissolve and a nuclear membrane forms around chromatin.
Cell undergoes Cytokinesis and splits the cell into two.
Is Cytokinesis different for Plants and Animals?
YES.
Plants: separated by a CELL PlATE
Animals: Separated through a pinching-in process called CLEAVAGE.
What is the function of CENTRIOLES?
To organize microtubules, for the formation of spindles and asters in the separation during Metaphase.
What are the three major checkpoints for Eukaryotes in Mitosis?
- G1-S: is the cell’s DNA suitable for replication?
- G2-M: Has the DNA been accurately replicated?
- Metaphase-Anaphase: Are he chromosomes aligned properly at the metaphase plate?
What is cloning?
Process in which identicall offspring are formed from a single parent cell.
What is budding?
asexual. When a small outgrowht from parent’s body breaks off and forms a separate but identical organism.
What is Vegetative Propagation/Fragmentation?
in which pieces of the plant (leaves roots, etc) grow into a complete new plant.
What is Vegetative Reproduction?
The generation of new plants on RUNNERS (Extention of stems where new plants develop and rely on the parent plant)
What is a blastula?
A fertilized egg undergoing rapid mitotic division forming a ball of cells.
What is TOTIPOTENT?
A nucleus that can give rise to an entire functional organism.
What is PLURIPOTENT?
When cells can differentiate into any of the 3 primary tissues: ectoderm, mesoderm and endoderm.