Cell Reproduction Flashcards
Epidermal Cells
Skin Cells
Cell Division
The process of creating new cells from an existing one
Cell Cycle
The life cycle of a cell (“birth” to death)
Periods of the Cell Cycle
- Interphase
- Mitosis
Interphase
The time span from one cell division to another (Cell grows and functions normally)
Interphase Stages
- G1 Phase
- G2 Phase
- S Phase
S Phase
The cell replicates its genetic material in order to prepare for mitosis
Sister Chromatids
A pair of identical chromosomes
Centromere
Holds the chromatids together
G1 and G2 Phase
Enzymes and proteins are made in order to prepare for mitosis (along with organelles)
Mitosis Stages
- Prophase
- Metaphase
- Anaphase
- Telophase
Prophase
- Nucleolus disappears
- Chromosomes thicken and become visible
- Centrioles move towards opposite ends of the cell
- Spindle Fibers attach to the kinetochores
Chromatin
Invisible DNA that is scattered throughout the nucleus
Spindle Fibers
A system of microtubules made by centrioles
Kinetochore
Part of the centromere of a chromosome
Metaphase
Chromosomes line up along the metaphase plate
Metaphase Plate
The equatorial region of the cell
Anaphase
Sister chromatids are separated by the contraction of the spindle fibers and the cell is pushed in opposite directions
Telophase
A nuclear membrane forms around each set of chromosomes and the nucleoli reappear
Cytokinesis
Splitting of cytoplasm between cells
Cleavage Furrow
Forms during Cytokinesis
Cell Plate
Forms during Cytokinesis in plant Cells
Diploid Cell
A cell that has two sets of chromosomes
Haploid Cell
A cell that has one set of chromosomes
Homologues
Pairs of the same chromosome
Homologous Chromosomes
Make up each pair and are similar in size and shape, also express similar traits
Gametes
Sex cells that are haploid
Meiosis
Each parent contributes a set of chromosomes to the child in order for the child to form gametes of its own
Gonads
Sex/Reproductive Organs
Testes
Male gonads
Ovaries
Female gonads
Germ Cells
Type of cell within the gonads that produce haploid gametes
Rounds of Meiosis
- Meiosis I
- Meiosis II
Meiosis I Stages
- Prophase I
- Metaphase I
- Anaphase I
- Telophase I
Prophase I
- Nuclear membrane disappears
- Centrioles move to opposite ends of the cell
- Homologous chromosomes line up side by side
- Crossing over occurs
Synapsis
The lining up of homologous chromosomes
Tetrad/Bivalent
Consists of four chromatids
Crossing-Over
The exchange of segments between homologous chromosomes
Alleles
Different forms of the same gene
Chiasmata
Regions where the homologous chromosomes are held together as the result of crossing-over
Metaphase I
Tetrads line up at the metaphase plate
Anaphase I
Tetrads are separated and moved towards opposite poles
Telophase I
The nuclear membrane forms around each set of chromosomes
Meiosis II
The second round of meiosis that results in four genetically different gametes
Gameteogenesis
The creation of gametes
Spermatogenesis
The creation of sperm cells
Oogenesis
The creation of a ovum or female egg
Polar Bodies
Three other cells that are produced during oogenesis that are reabsorbed by the female
Nondisjunction
Chromosomes fail to separate properly during meiosis
Down Syndrome
Defect that occurs due to three copies of Chromosome 21
Operon
The region of bacterial DNA that regulates gene expression
Structural Genes
Genes that code for enzymes needed in a chemical reaction
Promoter Gene
The region where the RNA polymerase binds to begin transcription
Operator
The region that controls whether or not transcription will occur
Regulatory Gene
Codes for a specific regulatory protein called the repressor
Repressor
Capable of attaching to the operator and blocking transcription
Inducer
Binds to the repressor and releases it from the operator, allowing transcription to occur
