Chapter 2: Mitosis and Meosis Flashcards
TO learn lol!
The Nucleus is
-Found in eukaryotes
-Membrane-bound
-Houses genetic material (DNA)
Nucleolus
-Where ribosomal RNA (rRNA) is synthesized
-Nucleolus organizer region (NOR)
DNA that encodes rRNA
Nucleoid
-Found in prokaryotes
-NOT membrane bound
Cytoplasm includes:
-Nuclear cellular organelles are contained here
Cytosol
Colloidal material surrounding organelles
Cytoskeleton
Made of extensive system of tubules and filaments. Includes:
-Microtubules
-Microfilaments
Microtubules:
Made up of the protein tubulin
Microfilaments
Derived from the protein actin
Endoplasmic Reticulum
An organelle that:
-compartmentalizes cytoplasm
-increases the surface area for biochemical synthesis
Smooth Endoplasmic Reticulum
Site of fatty acid and phospholipid synthesis
Rough Endoplasmic Reticulum
Rough is studded with ribosomes
-Site of protein synthesis
Mitochondria
Within plant and animal cells
-Site of OXIDATIVE phases of cellular respiration, which generate ATP
Chloroplasts
Contained in plants, algae, protozoans
-Site of photosynthesis
Centrioles (ONE OF THE TWO LITTLE CUTE THINGS IN THE CENTROSOME)
-Found in the centrosome (the region, or the the cute little paired thingies involved in mitosis)
-Organize spindle fibers for movement of chromosomes during meiosis and mitosis
-Made of MICROTUBULES
-(inside of every cell) come to ends of cells and microtubules pulls the cells apart
Chromosomes exist as ___________ ______ in diploid organisms
HOMOLOGOUS PAIRS
Homologous chromosomes
-Similar, but not identical (different versions of the same gene)
- Carry genes for the same inherited characteristics
-May carry different versions of the same gene
Alleles
Different versions of the same gene
Centromere
-Constricted regions on chromosomes
-Location of centromere established appearance of chromosome
Different locations of the centromere, establishing the appearance of the chromosome:
-Metacentric: centromere is positioned in the middle
-Submetacentric: Slightly above the middle
-Acrocentric: Above the middle line
-Telocentric: Centromere is literally located on the top, forming an upside-down “c” shape
Sister chromatids
Draw a line vertically down the middle of homologous chromosomes, and you get the sister chromatids
Long arm on sister chromatid
q Arm
Short arm on sister chromatid
p arm
Somatic Cells
the regular body cells that have homologous pairs of chromosomes
Humans have ___ chromosomes, meaning they have ___ homologous pairs
46
23
Represents the diploid number, 2n
Karyotype
Illustrates the physical a[[earance of the differnet pairs of homolougous chromosomes
Remember the matching up activity in bio lab?!
Meiosis converts the diploid numner (2n) of chromosomes to the ________
haploid number (n)
Note: n is the number of chromosomes
Genome
genetic information in the haploid set
Locus
Homologous chromosomes contain identical gene sites along their lengths
Each site is called a locus
Biparental inheritance
inheritance from two parents
(diploid organisms contain two copies of each gene)
Alleles
alternative forms of the same gene
Sex-determining chromosomes
NOT homologous
Behave as homologs in meiosis
Ex. X and Y
Zygote
single-celled fertilized egg of multicellular organisms
Karyokinesis
genetic material partitioned to daughter cells during nuclear division
Cytokinesis
Cytoplasmic division
Cell cycle
composed of interphase and mitosis
Interphase (brief summary)
S phase: DNA is synthesized
Two gap phases: (G1 and G2)
Seperate phase that is part of interphase
G0 phase: point within G1 phase where cells are nondividing, but at a metabolically active state
Cancer cells do NOT have a G0 phase
Interphase
characterized by the absence of visible chromosomes
-Chromosomes are generally extended and uncoiled, forming chromatin
Mitosis has 5 discrete stages:
-Prophase
-Prometaphase
-Metaphase
-Anaphase
-Telophase