Lab 1 Questions Flashcards
What is the function of the smooth endoplasmic reticulum?
-synthesizes lipids and steroid hormones
what is the function of the rough endoplasmic reticulum?
-synthesizes secretory, lysosomal, and membrane proteins
what is the function of the mitochondria?
-ATP synthesis
what is the function of the golgi apparatus?
-modifies, sorts, packages, and delivers proteins for lysosomes, cell membrane, or secretion
what is the function of the nucleus?
-acts as the cell control center
what is the function of the nuclear membrane?
-connection to the cytoplasm
what is the function of the nucleolus?
-assembles and synthesizes ribosomes
what is the function of the centrosomes?
-organizes the cytoskeleton
-organizing centers for microtubules
-builds the spindle apparatus
what is the function of the ribosomes?
-sites for protein synthesis
what are the membranous organelles?
-nucleus
-mitochondria
-rough ER
-smooth ER
-golgi apparatus
-lysosomes (not on models)
what are the non-membranous organelles?
-centrosomes
-ribosomes
-nucleolus
-cytoskeleton (not on models)
which two components make up the cytoplasm of the cell?
-cytosol
-organelles
what features can tell you if a cell is in interphase?
-nucleus is present
-chromosomes in chromatin form
-cell is not splitting
what is the purpose of mitosis?
-to produce two identical diploid daughter cells
how many chromosomes are present in a diploid human daughter cell?
-46
what occurs in interphase?
-G1 Phase
-growth and metabolism
-centrosome replication begins
-46 single chromosomes (46 chromatids)
-S Phase
-chromosomes replicate (still present as chromatin)
-always occurs before division
-replicates are called sister chromatids
-they attach to each other at the centromere
(kinetechore is formed)
-46 chromosomes, 92 chromatids
-G2 Phase
-growth and metabolism
-production of enzymes and other proteins
needed for cell division
-centrosome replication completed
what occurs in prophase?
-chromosomes condense (thicken+coil) (can now be seen individually)
-nucleoli disappear and the nuclear envelope breaks
-centrosomes move to either pole (ends of the cell)
-microtubules form the spindle apparatus
-attaches to
kinetochore
-moves
chromosomes to
the cell equators
what occurs in metaphase?
-46 chromosomes line up on the cell equator
what occurs in anaphase?
-cytokinesis begins
-spindle microtubules shorten
-pulls the kinetochores
to separate the sister
chromatids
-46 chromatids migrate to each pole
what occurs in telophase?
-reverse of prophase
-chromosomes uncoil into chromatin
-nucleoli and nuclear envelope reappears
-spindle disassembles
-cytokinesis is completed (during or after telophase ends)
are the daughter cells produced by mitosis diploid or haploid?
-diploid
after mitosis and cytokinesis are completed what stage will the daughter cells enter if they are going to divide again?
-Interphase G1
after mitosis and cytokinesis are completed what stage will the daughter cells enter if they are NOT going to divide again?
-G0
what is the purpose of meiosis?
-to create 4 haploid gametes from 1 diploid germ cell
-gametes will combine (sperm + ovum) to form a diploid cell
what is the main purpose of meiosis I?
-to seperate homolgous chromosomes to create 2 haploid cells (intermediate)
-23 chromosomes (46 chromatids)
what is the main purpose of meiosis II?
-to seperate sister chromatids to create 4 haploid gametes
-23 chromosomes (23 chromatids)
what occurs in prophase I of meiosis?
-homologous chromosomes attach together (form tetrads)
-crossing over
-piece of 1 chromatid
exchanges with a
matching piece of
the homologous
chromosome
what occurs in metaphase I of meiosis?
-23 tetrads line up along the cell equator
what occurs in anaphase I of meiosis?
-tetrads separate into homologous chromosomes (with 2 sister chromatids) and migrate to each pole
-done so with the
spindle apparatus
-chromatids do not separate
is anything different in interphase and telophase of meiosis?
-nope!
how is meiosis II different from meiosis I
-just has 23 chromosomes instead of 46
-metaphase II
-23 chromosomes line
up at the equator
-anaphase II
-23 chromatids
migrate to each pole
what cellular process allows the zygote to change into the morula?
-mitosis (cleavage divisions)
-same size, but the morula is composed of more cells
what becomes the chorion in later stages of development?
-trophoblast of the blastocyst
what becomes the embryo in later stages of development?
-the epiblast
-forms the 3 germ layers of the embryo
what structures are derived from the embryoblast (inner cell mass)
-bi-layered embryonic disc
-epiblast (forms 3 germ layers)
-hypoblast (forms the yolk sac)
- amnion/amniotic cavity
what structures are derived from mitosis of the epiblast?
-embryo (3 germ layers)
-amnion
-amniotic cavity
what structures are formed from the mitosis of trophoblast cells?
-chorion
-chorionic villi
what structure produces the first red blood cells?
-yolk sac
what structures are formed from the mitosis of the hypoblast
-yolk sac
-indirectly forms the allantois (umbilical cord + bladder)
what structure forms the fetal part of the placenta?
-chorionic villi
