Chapter 2: Mitosis and Meiosis Flashcards
Are segments of the DNA that code for specific proteins which direct the metabolic activities of cells.
Genes
Is organized into chromosomes which serve as vehicles for transmitting genetic information.
DNA
Characteristically defined by the presence of a nucleus and other membranous organelles.
Eukaryotic cell
A membrane-bound structure that houses the genetic material, DNA, which is complexed with an array of acidic and basic proteins into thin fibers.
Nucleus
Present inside the nucleus which is an amorphous component where ribosomal RNA (rRNA) is synthesized and where the initial stages of ribosomal RNA (rRNA) assembly occur
Nucleolus
Portions of the DNA that encode rRNA.
Nucleolus Organizer Region (NOR)
Lacks a nuclear envelope and membranous organelles.
Prokaryotic cell
The genetic material of prokaryotic organisms.
Circular DNA
A region in the cytoplasm of prokaryotic organisms where the genetic material is clustered into.
Nucleoid region
True or False. The genetic material in prokaryotic organisms undergoes the extensive coiling characteristic of the stages of mitosis, during which the chromosomes of eukaryotes become visible.
False. Genetic material in prokaryotes does not undergo coiling.
True or False. Prokaryotic cells do not have a distinct nucleolus and do not contain genes that specify rRNA molecules.
False. Though deprived of a nucleolus, prokaryotic cells do contain genes that code for rRNA.
The remainder of the eukaryotic cell within the plasma membrane, excluding the the nucleus.
Cytoplasm
Compartmentalizes the cytoplasm, greatly increasing the surface area available for biochemical synthesis.
Endoplasmic reticulum (ER)
It serves as the site for synthesizing fatty acids and phospholipids.
Smooth ER
It serves as the site for synthesizing protein where it is studded with ribosomes.
Rough ER
Serves as sites where genetic information contained in mRNA is translated into proteins.
Ribosome
Are found in most eukaryotes, including both animal and plants, and are sites of the oxidative phases of cell respiration.
Mitochondrion
Cytoplasmic bodies, each located in a specialized region called the centrosome, are associated with the organization of spindle fibers that function in mitosis and meiosis.
Centrioles
Where centrioles are derived from. Associated with the formation of cilia and flagella (hair-like and whip-like structures for propelling cells or moving materials
Basal body
Play an important role in the movement of chromosomes as they separate during cell division.
Spindle fibers
Spindle fibers are made up of microtubules consisting of polymer of what protein?
Tubulin
What phase of the cell cycle wherein centrioles start to organize spindle fiber?
Prophase
Are the spindle fibers that are most directly responsible for chromosome migration by making contact with, and adhering to the kinetochore as they grow out of the centrosome region.
Kinetochore microtubules
Are found in plants, algae, and some protozoans, are associated with photosynthesis, the major energy-trapping process on Earth.
Chloroplast
In addition to the plasma membrane, plant cells also have what structure that is made primarily of polysaccharides known as cellulose.
Cell wall
Covering over the plasma membrane of animal cells consisting of glycoproteins, and polysaccharides. It provides biochemical identity at the surface of cells.
Glycocalyx or Cell Coat
These molecules act as recognition sites that transfer specific chemical signals across the cell membrane.
Receptor molecules
Constricted region on the chromosome, whose location establishes the general appearance of each chromosome
Centromere
The shorter arm of a chromosome.
p arm
The longer arm of a chromosome.
q arm
A chromosome whose centromere is located in the middle of the chromosome.
Metacentric chromosome
A chromosome whose centromere is located between the middle and the end.
Submetacentric chromosome
A chromosome whose centromere is located close to the end.
Acrocentric
A chromosome whose centromere is located at the very end.
Telocentric
DNA diameter
2 nm
Made of 2 units of histone octamer each wrapped with 147 DNA base pairs, and a unit of H1 histone wrapped with DNA spacer.
Nucleosome
Nucleosome size
6 nm X 11 nm flat disk
Made of 6 units of histone octamer each wrapped with 147 DNA pairs, and 6 units of H1 histone each wrapped with spacer DNA.
Solenoid
Solenoid size
30 nm
Composed of several solenoid units that are tightly looped.
Looped domain
Size of the looped domain
80-100 nm
Composed of several tightly looped domains.
Chromatin fiber
Size of Chromatin fiber
300 nm
What phase of the cell cycle is the chromosome most visible.
M phase
True or False. Somatic cells derived from members of the same species contain an identical number of chromosomes (diploid number, 2n)
True
Is a pair of chromosomes whose centromere location, size, and gene loci are identical.
Homologous chromosomes
Gene sites found on chromosomes.
Locus (plural. loci)
Alternative forms of a gene are called?
Alleles
True or False. The locus for a specific gene is present in both pairs of homologous chromosomes but they need not be identical in genetic sequence.
True.
Inheritance from two parents is called?
Biparental inheritance
Collection of all the genetic information contained in a haploid set of chromosomes.
Genome
True or False. Sex determining chromosomes (e.g. the X and Y chromosomes in humans) are not homologous in size, centromere placement, arm ratio, or genetic content.
True
True or False. Y chromosome humans are considerably smaller and lack most of the gene loci contained on the X.
True
The non-dividing phase of the cell cycle. Interval between divisions.
Interphase
What phase of the cell cycle does the cell exhibit cell growth, synthesis of proteins, and lasts about 5 hours in human cells?
G1 phase