Exercise 2: Cell Structure and Division Flashcards
3 common characteristics of cells:
- The outer boundary of the cell is the plasma membrane.
- All cells store genetic information in the form of DNA
- Everything inside the plasma membrane that is not DNA or nucleus is cytoplasm.
Levels of Orgaization
- Organelles
- Cells
- Tissues
- Organs
- Systems
Characteristics/Function of the nucleus.
- Contains nucleus
2. Pattern for building all proteins for the cell.
Characteristics/Function of the nuclear envelope.
- Membrane around nucleus.
2. DNA can not cross it.
Characteristics/Function of the nucleolus.
- Area in nucleus
2. Site of mRNA synthesis.
Characteristics/Function of chromatin.
Unwound DNA inside nucleus.
Characteristics/Function of the nuclear pores.
- Opening in nuclear envelope
2. Allows mRNA out of nucleus.
Characteristics/Function of the cytoskeleton.
- Several different types.
2. Internal scaffolding for cell.
Characteristics/Function of the cytoplasm.
- Semi-solid substance
- Fills space between plasma membrane and nucleus
- Composed of organelles suspended in cytosol.
Characteristics/Function of the Plasma membrane.
- Outer boundary of cell
- Lipid bilayer.
- Regulates what enters or leaves cell.
Characteristics/Function of the Ribosomes
- Composed of rRNA and proteins
- Site of mRNA translation.
- Free ribosomes are in cytoplasm
- Fixed ribosomes stud outside of RER.
Characteristics/Function of the Rough Endoplasmic Reticulum RER
- Membraneous organelle
- Network of channels
- Site of protein synthesis
Characteristics/Function of Mitochondrion
- Membraneous organelle
- Bean-shaped
- Site of ATP synthesis
Characteristics/Function of a Lysosome
- Membrane bound vesicle
2. Contains hydrolytic enzymes
Characteristics/Function of the smooth endoplasmic reticulum (SER)
- Membraneous organelle
- Forms tube-like structure
- Site of lipid synthesis.
Characteristics/Function of a centriole.
- Paired organelle
2. Organizes spindle fibers during mitosis.
Characteristics/Function of the Golgi Apparatus
- membraneous organelle
- Forms stack of plates
- Proteins packaged for secretion
Characteristics/Function of a transport vesicle
- Membrane-bound vesicle
2. Transports substances throughout the cell.
Mitosis
The division portion of the cell cycle, ensure that each daughter cell receives the full and correct number of chromosomes from the parent.
Interphase
- Consists of G1, S, & G2 phases
- Time during which cell is carrying out its functions and growing larger.
- Repliates DNA as it prepares to divide.
First Growth (G1) phase
- Cells grow larger
2. Carries out cellular functions
Synthesis (S) phase
- DNA is replicated
- Sister chromatids are formed.
- Organelles increase in number
Second Growth (G2) Phase
- Cells grow larger
- Prepares to divide
- Continues to carry out cellular functions
Mitosis
- Equal division of DNA
2. Consists of four stages: prophase, metaphase, anaphase, telophase
Cell Division
- Consists of the four stages of mitosis and cytokinesis.
2. Time during which original cell produces two identical daughter cells.
Cytokinesis
- Division of cytoplasm
2. Results in two equal cells.
Stages of Mitosis: Interphase
- Cell carries out its functions.
- DNA is diffuse and called chromatin
- No chromosomes are visible
- Cell replicates DNA and organelles as it prepares to enter mitosis
Stages of Mitosis: Prophase
- First stage of mitosis
- Chromatin condenses into visible chromosomes called sister chromatins
- Sister chromatids are the result of DNA replication, two identical chromosomes connected by a centromere
- Nuclear envelope begins to break down.
- Spindle fibers appear.
Stages of Mitosis: Metaphase
- Second stage of mitosis
- Nuclear envelope is gone
- Centromere of each sister chromatid attaches to spindle fibers
- Sister chromatids line up along equator of cell.
Stages of Mitosis: Anaphase
- Third stage of mitosis
- Sister chromatids separate at centromere to produce individual chromosomes
- Chromosomes begin to migrate to the poles.
Stages of Mitosis: Telophase
- Fourth stage of mitosis
- Chromosomes reach poles
- Spindle fibers disappear.
- Nuclei begin to reform
Stages of Mitosis: Cytokinesis
- Physical division of cell following division of DNA.
- When complete, two identical daughter cells are formed
- Each daughter cell enters interphase and entire process begins again.
A group of like cells group together to form_____
Tissue
Which of the following choices is NOT found in all cells?
Centrioles
Plasma Membrane
Nucleus
Cytoplasm
Centrioles
Which organelle is the site of ATP synthesis?
Mitochondrion
During interphase DNA is found as _____?
Chromatin
Which organelle is the internal scaffolding of a cell?
Cytoskeleton
During what phase is DNA replicated?
S Phase
During which phase of mitosis do sister chromatids become visible?
Prophase
During which stage of mitosis do the sister chromatids separate into chromosomes?
Anaphase
Which of the following is the physical division of a cell?
Cytokinesis