physical basis of heredity

heredity

transmission of traits from generation to generation

dna

the basis of heredity

variation

deals with genetic differences between organisms

cell division

process involved in heredity and variation; leading to the distribution of genetic material.

matthias schleiden

theodore schwann

rudolf virchow

were key figures in the development of cell theory

prokaryotic

a cell that can function on its own; lack nucleus and membrane bound organelles; bacteria and archaea

eukaryotic

requires multiple cell to work as an organism, complex, contain true nucleus; animals and plants

plasmid

a small, circular DNA molecule found in bacteria or prokaryotic cell

chromosome

stuctural units that contain the DNA forms due to condensation and stacking of DNA

pellicle

outer covering of chromosome, encloses matrix

centromere

primary constriction of a chromosome that holds sister chromatids together.

tetrads

formation of 2 homologous chromosomes during meiosis, each made up of two sister chromatids.

satellite chromosomes

secondary restriction

satellite

chromosomal distal end

nucleolus

organelle formed by satellite chromosome

chromomere

regions of tightly folded DNA; bead like

chromonema

coiled chromatin thread; visible within the nucleus during cell division

matrix

houses the chromatin; surrounds (chromonemata) chromomere and chromonema

ernst haeckel

proposed that genetic material of eukaryotes is inside the nucleus

chromatin

material of which chromosomes are made up of ____; dark network

telomeres

distal ends of chromosome; 1st constriction

sister chromatids

homologous chromosomes but not on the same chromosome

chromosomal abnormality

more than one centromere

cytoplasm

where all organelles are suspended, Plays an important part in the cell

division as it allows the chromosomes to move freely

ribosomes

site of protein synthesis and translation of the genetic code from the mrna; attached to endoplasmic reticulum

rough er

contains ribosomes

smooth er

site of lipid synthesis

golgi apparatus

net-like staining bodies engaged in secretion; transports and sorts the molecules that is needed by the cell; wave like structure and forms vesicles

vesicles

sac like structures that hold molecules for transporation

vacuoles

for storing nutrients and water mainly for plants

somatic chromosomes

found in the body and are presented by 2n; contains 2 identical copies of each chromosomes

gametic chromosomes

half the number of somatic chromosome (haploid)

non sister chromatids

chromatid of a homologous chromosome that is not attached on the same centromere; recombination is evident

telomere

imparts stability to the chromosome which retains its identity and individuality through cell cycles for many cell division

secondary constriction

narrow region on a chromosomes

organizer region

the production of nucleolus is associated with the secondary constriction and therefore is also called

nucleus organizer chromosome

satellite chromosomes are often referred to as

nuclear membrane

in eukaryotes, __ separates the genetic material from the cytoplasm

mitochondria

small bodies whose primary function is to provide cellular energy through respiration and oxidation

endoplasmic reticulum or ergastoplasm

a cytoplasmic double walled membrane folded in layers that appear to be connected w the cell membranes

centrosome and the accompanying centriole

organelle that duplicates itself and shows continuous inheritance between cell generations

chloroplasts

plastids in plant cell which contain chlorophyll and serve as the photosynthetic factory of plants

nucleus

primary director of cellular activity and inheritance

¼ micron, 30 microns

condensed chromosome may be as short as ___ or as long as ___

kinetochore proteins

centromere is a permanent well-defined region of the chromosome where the ____ attach to.

depolymerization

The spindle fibers bind to kinetochore and the ___ of the spindle fibers enables the chromosome to move to the opposite poles

metacentric

when the centromere is located at the middle

submetacentric

when the centromere is close to the middle

acrocentric

when the centromere is located near one end

telocentric

when the centromere is at the end of the chromosome

satellite

The pinching off a small chromosomal section forms the ___

chromomeres

smaller beads on the string seen when a mitotic chromosome is stretched out

knobs

larger beads on the string seen when a mitotic chromosome is stretched out