Physiology 1 chapter 3 Flashcards
What is cytokinesis?
physical division of the cell into 2 new daughter cells
When does cytokinesis occur?
telophase
How many chromosomes does a human cell have at the end of anaphase?
92
What directs the splicing of precursor mRNA for post transcription modification?
Small nuclear RNA (snRNA)
precursor mRNA definition
originally transcribed single strand is large and immature. Must be spliced down
Messenger RNA (mRNA) description
carries the genetic code from the nucleus to the cytoplasm
Transfer RNA (tRNA) description
carries activated amino acids to the ribosomes for assembly into proteins
Ribosomal RNA (rRNA) description
joins with ribosomes to form proteins
MicroRNA description
very short, single strand of RNA that regulates activity for gene transcription and translation
What is located where 2 chromatids meet in a single chromosome?
Centromere
What is located at the ends of the chromatids to protect them from degrading?
telomere
How many chromosomes does a typical human gamete cell contain?
23
When are the sister chromatids pulled apart into their own individual chromosomes?
anaphase
What is the first thing that occurs during cell reproduction?
duplication of all DNA in the chromosomes
What is the second thing that occurs during cell reproduction?
formation of spindle and condensation of chromosomes
What is the third thing that occurs during cell reproduction?
nuclear envelope fragments
What is the fourth thing that occurs during cell reproduction?
equatorial plate of the mitotic spindle forms
What is the fifth thing that occurs during cell reproduction?
separation of the 46 pairs of chromatids into 46 daughter chromosomes
What is the sixth thing that occurs during cell reproduction?
mitotic apparatus dissolves, new nuclear membrane forms
what is formed in the cytoplasm and grows the microtubules that accomplish mitosis?
centrosome
how many chromosomes does a typical human cell in prophase contain?
46
what type of RNA forms the peptide bonds that unite amino acids?
rRNA
when does the mitotic spindle disappear as new nuclear membrane forms around each new nucleus?
telophase
what is the order of events that take place for cell reproducing?
- replication
- prophase
- prometaphase
- metaphase
- anaphase
- telophase
when do chromosomes line up in the middle of the cell as the microtubules of the centrosome connect to each centromere?
metaphase
what contributes to the mitotic spindle/apparatus?
centrosomes, chromatids, microtubules
what does NOT contribute to the mitotic spindle?
telomere
how many chromosomes are in atypical human cell in interphase?
46
when does the replicated DNA condense into chromosomes?
prophase
what is a small molecule that typically inhibits or decreases activity of gene transcription or translation?
miRNA
how many chromosomes does a typical human cell have at the beginning of telophase?
92
what are the areas/components of a chromatid?
histone protein, telomere, centromere, DNA helix
replication
duplication of all the DNA in the chromosomes occurs
prophase
spindle forms and chromosomes condense
prometaphase
the nuclear envelope is fragmented as microtubules attach aster to chromatids at centromeres
metaphase
chromatids form the equatorial plate of the mitotic spindle
anaphase
the 46 pairs of chromatids are separated into 46 daughter chromosomes
telophase
the mitotic apparatus dissolves, new nuclear membrane forms around each daughter chromosome
when does a cell contain 92 chromosomes?
anaphase
