Mitosis & Meiosis Flashcards
What are the 6 stages of the cell cycle?
- interphase
- prophase
- metaphase
- anaphase
- telophase
- cytokinesis
What are the 8 phases of meiotic cell division?
- prophase I
- metaphase I
- anaphase I
- telophase I & cytokinesis
- prophase II
- metaphase II
- anaphase II
- telophase II & cytokinesis
What are the 8 phases of meiotic cell division?
- prophase I
- metaphase I
- anaphase I
- telophase I & cytokinesis
- prophase II
- metaphase II
- anaphase II
- telophase II & cytokinesis
How many chromatids does a human somatic cell contain after interphase but before mitosis?
92
What event occurs in prometaphase of mitosis?
the nuclear envelope fragments
What event occurs in prometaphase of mitosis?
the nuclear envelope fragments
T or F: the nuclear envelope fragments in prometaphase of mitotic division in both eukaryotic phytoplankton and most other eukaryotes?
FALSE. the nuclear envelope fragments in most eukaryotes but remains intact in diatoms and dinoflagellates
Define heredity
transmission of traits from one generation to the next
Define genetics
the study of heredity and the variation of inherited characters
Genetics are the inherited properties or features of an organism
Define gene
A unit of hereditary information consisting of a specific nucleotide sequence in DNA
Genes specify the organism’s inherited traits
Define genome
A cell’s complete set of DNA
Define allele
Alternative version (variation of) a gene that may produce a visible difference (phenotypic effect)
ex. Hair colour
Define sex chromosome
Chromosomes that determine the sex of an organism
- either XX or XY
Define somatic cell
All cells of the body except gametes and their precursor cells
How is genetic material organized in prokaryotic cells?
The genome is often a single, circular DNA molecule located in the nucleoid
How is genetic material organized in eukaryotic cells?
The genome usually consists of a number of linear DNA molecules located in the nucleus and mitochondria (and chloroplasts of plant cells)
Define karyotype
An ordered display where homologous chromosomes are arranged by length in pairs
How many pairs of autosomes do humans have?
22
Define sister chromatid
Joined identical copies of the original chromosomes
Define homologous chromosomes
A pair of chromosomes that are of similar length, staining pattern, and centromere location, but may have different varieties of a gene (different alleles)
One of the chromosomes come from the biological mother’s egg; one from the biological father’s sperm
T or F: all humans have at least one X sex chromosome, but not all humans have Y chromosomes?
TRUE
Define gene locus
The location of a gene on a chromosome
When are chromosomes uncondensed? What form do they take during this period?
Are they visible at this time?
When cells are not dividing
Chromosomes are in the form of long, thin chromatin fibres (even when replicating)
NOT visible
When do chromosomes start to condense/coil? Are they visible at this time?
After replication, when they are heading into mitosis or meiosis
They are visible
T or F: after DNA replication, each duplicated chromosome is composed of 2 sister chromatids
TRUE
What protein holds together sister chromatids along their lengths?
Cohesins
Define cohesin
A protein complex that helps regulate the segregation of the sister chromatids during cell division
They hold together the two sister chromatids to form one chromosome until they’re ready to be separated
Define centromere
The region on each sister chromatid where the sister chromatid is most closely attached to its sister chromatid
What are the two kinds of nuclear cell division?
Mitosis and Meiosis
Define cytokinesis
The process of the cytoplasm (the rest of the cell) being divided that usually co-occurs during the Telophase stages of mitosis and meiosis when the daughter cells are produced
Define cytokinesis
The process of the cytoplasm (the rest of the cell) being divided that usually co-occurs during the Telophase stages of mitosis and meiosis when the daughter cells are produced
What are the 2 phases of a somatic cell?
Mitotic phase alternates with interphase in the cell cycle
Describe interphase
The longest phase of a cell’s life (~90%), when a cell grows and copies its chromosomes BEFORE mitosis or meiosis. It is also the time when a cell performs its functions
What are the 3 subphases of interphase and what occurs during each?
- G1: cell grows
- S: chromosomes are duplicated (synthesis) and cell grows
- G2: cell grows
During all subphases, cells grow by producing organelles and proteins
Define mitosis
The division of the nucleus of a eukaryotic cell so that the two resulting daughter cells have the identical genetic information as each other and the parent
What are the functions of mitosis?
Asexual reproduction in unicellular organisms
Asexual reproduction, growth, repair, and cell replacement in multicellular organisms