Physical Basis of Heredity - Laboratory Flashcards
study of genes, heredity, and genetic variation on living organisms
genetics
explores how traits are passed down from parents to offspring, the underlying mechanisms of inheritance, and how genetic information influences the development and function of living things
genetics
passing on of traits from parents to their offspring
heredity
actual transmission of characteristics like eye color, height, and disease susceptibility from one generation to the next
heredity
is the foundation of heredity
genetics
demonstrates the principles of genetics
heredity
provides the scientific framework to understand how heredity works
genetics
are units of heredity
genes
made of DNA, carry the instructions that determine the traits the individual inherits
genes
observation of how traits are passed down through generations (heredity) has been crucial in developing and testing the principles of genetics
heredity
is the observable phenomenon
heredity
scientific study that explain how heredity occurs
genetics
most distinct organelle
nucleus
nucleus is membrane bounded by the
nuclear membrane
controls and regulates functions of other organelles
nucleus
stores genetic information
nucleus
where DNA duplication occurs
nucleus
Nucleus has the following components:
nucleoplasm
nucleolus
chromatin materials
how can we know chromosomes are homologous
size
shape
location of centromere
the Nuclear envelope is connected to flattened sacs called
cisternae
inner membrane of the cisternae is in contact with ___ ___
chromatin fibers
outer membrane of the cisternae is covered with ___
ribosomes
nucleoplasm is also called
nuclear sap or karyolymph
fills up nuclear space, viscous than cytoplasm
nucleoplasm
spheroidal; very large in cells and is active in protein synthesis
nucleoli
can be single or multiple
nucleoli
tissue where there are multiple nucleoli
skeletal tissue
synthesizes and assembles RNA molecules and proteins > Ribosome
Nucleoli
contains genes
chromatin materials
Centromere is near the center of the chromosome
metacentric
Centromere is off-center, making one arm of the chromosome longer than the other
submetacentric
Centromere is near the end of the chromosome, but not at the telomere region
acrocentric
Centromere is at the end of the chromosome, also known as the telomere region
telocentric
are DNA segments that hold sister chromatids together
centromere
chromosome is composed of
DNA + protein
protein in chromosome
histone
DNA + histome =
nucleosome
joins nucleosome
linker DNA
action of nucleus at cell division
step 1: ____ and ___ disappear
nuclear envelope
nucleolus
action of nucleus at cell division
step 2: ___ condensed into ___
chromatin
chromosomes
dark stained bodies under the microscope
chromosomes
action of nucleus at cell division
step 3: DNA + proteins (_____) condenses into ___ ___
nucleosome
chromatin fiber
chromatin fiber is about ___ nm
30nm
a non dividing cell is at ___
interphase
length may vary based on cell type
cell cycle
cyclical process of growth and mitosis
cell cycle
build up of cytoplasm and synthesizing of organelles (growth) and animal cells synthesizes centrioles
G1 phase
interphase is divided into 3
g1
s
g2
synthesis phase, DNA replication
s phase
synthesis of microtubules, further synthesis of RNA molecules getting ready for karyokinesis
g2 phase
also known as karyokinesis
mitosis
will not start without passing by mitosis
meiosis
chromosomal abberations may happen when __ phase is interrupted
S
check points in cell cycle
G1 checkpoint
G2 checkpoint
M checkpoint
are changes in the number or structure of chromosomes
chromosomal abberations
checkpoint make sure that microtubules are assembled and other necessary components
G2 checkpoint
checkpoint before telophase
checkpoint M
preparatory stage for mitosis
interphase
phase where there is visible nucleus w/ 1 or more distinct nucleoli
interphase
chromosomal form is irregular-granular
interphase
what form of chromosome in interphase
irregular-granular
part of interphase where there is cell growth, RNA nad protein synthesis takes place, and there is building of new protoplasm and cytoplasmic organelles
g1 phase
part of interphase where DNA synthesis and replication takes place and centriole reproduction begins
s phase
part of interphase where RNA and protein synthesis conintues, DNA content represented as 2C becomes 4C after S phase
s phase
part of interphase where completion of DNA synthesis and replication occurs, RNA and protein synthesis occurs, and cell is preparing for mitosis
G2 phase
the amount of DNA in a particular species is 12C. What is the DNA content of a cell at:
G2
24C
the amount of DNA in a particular species is 12C. What is the DNA content of a cell at:
S
24C
the amount of DNA in a particular species is 12C. What is the DNA content of a cell at:
G1
12C
mitosis vs meiosis major differences
cell type involved
of chromosomes (2n vs n)
amount of DNA and genes
karyokinesis followed by cytokinesis
mitosis
cell division for somatic cells
mitosis
has a equational division only
mitosis
cell division for sex cells
meiosis
composed of reduction division and equational division
meiosis
meiosis I is a ___ division
reduction
meiosis II is a ___ division
equatorial
phase where condensation of chromosome occurs, nucleolus disappears, and nuclear envelop disintegrates
prohpase
s a protein structure that connects chromosomes to spindle fibers during cell division.
kinetochore
are microtubules that attach to chromosomes during cell division.
kinetochore microtubule
are microtubules that extend between the poles of a cell without attaching to chromosomes.
non kinetochore microtubule
are hollow tubes that make up a radial structure called an aster.
aster microtubule
anchor the spindle poles to the cell membrane
aster microtubule
is a star-shaped structure in the nucleus of animal cells that helps align chromosomes during cell division
aster
are spindle microtubules that help separate the poles of a cell during mitosis.
polar microtubules
two sister chromatids joined at centromere
chromosome
is a structure found in eukaryotic cells from which microtubules emerge.
microtubule organizing center
alignment of the chromosomes at the equatorial plate
metaphase
sister chromatids move towards opposite poles
anaphase
s the stage of cell division when sister chromatids separate and move towards the spindle poles.
anaphase A/ early anaphase
involves both the elongation of overlap microtubules and the use of two distinct sets of motor proteins
late anaphase
formation of two daughter cells
telophase
microscopic observation includes:
observation of prepared slide
squash preparation for allium cepa
mitotic index for allium cepa
mitotic index formula
MI = # of cells undergoing mitosis / total # of observed cells *100
prepared slide of allium cepa root tip is observed under ___
HPO
squash method procedure:
- fix root tip in ___
70% ethyl alcohol
squash method procedure:
transfer the fixed root tip to a __ ___
clean slied
which portion of the root tip is cut?
terminal portion
how long is the terminal portion to be cut
~3mm
what region is cut in the root tip
root cap
s a tissue at the tip of a plant root that protects the growing tip and helps the root grow through soil
root cap
root cap is also called
calyptra
is a small region at the tip of a root in which all cells are capable of repeated division and from which all primary root tissues are derived.
meristematic region
squash preparation procedure:
- cut a thin section from the ___ region. Discard the rest of the root.
meristematic region
squash preparation procedure:
- add _ to ___ drops of ____ ___ ___ on the thin section and squash it with a bent needle
1 to 2 drops of lacto aceto orcein
squash preparation procedure:
drop of lacto aceto orcein and squash it using a ___ ___
bent needle
squash preparation procedure:
cover the smear with a ___ ___
cover slip
squash preparation procedure:
gently tap the coverslip with the end of unused ___ of a pencil to spread the chromosomes
pencil
squash preparation procedure:
___ the preparation by gently passing it through the flame of a ___ ___
heat
alcohol lamp
squash preparation procedure:
observe under ___
HPO
squash preparation procedure:
If the chromosomes are deeply stained, destain by adding a drop of ____ ____ ___ on one side of coverslip and place a piece of absorbent paper at the opposite end
45% acetic acid
refers to a staining solution used in microscopy, particularly for visualizing chromosomes, which is composed of a mixture of lactic acid, acetic acid, and orcein dye
lacto aceto orcein
farmer’s solution is composed of
formalin-acetic acid fixative
hich is essentially a concentrated form of vinegar, removes stains by acting as a mild acid that breaks down the chemical bonds of certain stain components, like grease, dirt, and mineral deposits, allowing them to be easily lifted and washed away with water
acetic acid
observe slides
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