Reproduction & chromosome transmission 3 Flashcards
Chromosomes
Are structures within living cells that contain the genetic material
Prokaryotes
Dont have a nucleus or membrane bound organelles
Nucleiod
Where the prokaryote chromosomes are found
Eukaryotes
Have a nucleus & contain membrane bound organelles
Cytogenetics
Field that studies chromosomes
Karyotype
An organized representation of the chromosomes within a cell
Eukaryotic chromosomes are inherited in _______
Sets
Diploid
Chromosomes that are a pair ( 2 sets of chromosomes)
Homologs
Are the pair of chromosomes that make a set (homologous pair where they are identical in shape & size & if one gene is found on one homolog then its also found on the other homolog)
Alleles
Two homologs that carry different verisons of the same gene
The _________ are not homologous pairs (Differ in shape & size & wouldnt contain the same gene)
Sex chromosomes (X & Y)
Homozyous
Both homologs carry the same alleles
Heterozygous
Both homologs carry different alleles
Locus
Where the gene is located
Human somatic cells contains _____________
2 sets of 23 chromosomes
Asexual reproduction
When a cell divides to produce two new cells (the orginal cell is called the mother cell & the new cells are called the daughter cells)
Bacteria reproduce asexually through ___________
Binary Fission
What is the process of binary fission?
- The mother cell duplicates to make more genetic material
- Ftz (protein) assembles at the location where the septum will be
- Ftz forms the septum which is a cell wall for the two daughter cells
- The two daughter cells seperate & the mother cell has made two new daughter cells (They are usuallly identical cause they are copies of the mother cell)
Eukaryotic cells make daughter cells through what process?
Cell Cycle
What are the phases of the cell cycle?
- Interphase
- Mitosis phase
The interphase is made up of what?
- Gap phase (G1 & G2 phase)
- Synthesis phase (S phase)
The _____ phase is a nondividing phase
G0
During the ____ phase a cell is grows where it reaches a restriction point & goes to the S phase
G1
After the G1 restriction point a cell goes to the ________ where the chromosomes are replicated
S phase
Chromatids
Two identical copies of chromosomes that are formed during the S phase & are joined together at the centromere to form sister chromatids (Dyad)
After the ______ phase a cell has twice as many chromatids (chromosomes) than it did in the G2 phase
S phase
Kinetochore
Group of protiens that are on the centromere & help hold the sister chromatids together
During the ____ phase a cell gains the material needed for nuclear & cell division
G2 phase
After the G2 phase a cell goes to the ____ phase where mitosis occurs
M phase
During ________ the replicated chromosomes are distrubted & dividing a cell nucleus into two nucleis so that each daughter cell recieves the same verison of the chromosomes
Mitosis
A human cell in the G2 phase has 92 chromosomes which has 46 pairs (sets) during ________ those 46 chromosomes are seperated into two nucleis that contain 46 chromosomes each
Mitosis
After the M phase the two daughter cells are formed by a process called what?
Cytokinesis
The _______ organizes & sorts eukaryotic chromosomes
Mitotic spindle apparatus (Mitotic spindle)
The transmission of chromosomes during the divison of eukaryotic cells involves a process called what?
Mitosis
What are the phase in mitosis?
- Prophase
- Prometaphase
- Metaphase
- Anaphase
- Telophase
During ___________ the chromatids become condense & more visible
Prophase (start of mitosis)
After the prophase is __________ where the sister chromatids become attatched to the spindle
Prometaphase
After the prometaphase is _________ where the sister chromatids align in the middle
Metaphase
After metaphase is _______ where the chromatids divide & go to their individual poles at each end of the cell
Anaphase
After Anaphase is __________ where the chromatids reach their poles & decondense & two seperate nucleis are formed
Telophase
After telophase is ____________ where the two nuclei are seperated into each daughter cell
Cytokensis
___________ & ___________ produce two daughter cells having the same number of chromosomes as the mother cell
Mitosis & Cytokinesis
Diploid cells divide by a process called what?
Meiosis
Meiosis
A process where haploid cells (cells with only one set of chromosome) are formed
Meiosis produces cells that are ________
Haploid
What are the phases of meiosis?
- Prophase of Meiosis 1
- Prometaphase of Meiosis 1
- Metaphase of Meiosis 1
- Anaphase of Meiosis 1
- Telophase of Meiosis 1 & Cytokinesis
- Meiosis 2
What are the stages of Prophase of Meisosis 1?
- Leptotene Stage
- Zygotene Stage
- Pachytene Stage
- Diplotene Stage
- Diakinesis Stage
Leptotene
Replicated chromosomes begin to condense & become visble
Zygotene Stage
Involves synapsis- which the homologous chromosomes recognize each other to align themselves
Pachytene Stage
The homologs are completely aligned (Bivalent- contains two pairs of sister chromatids(4 chromatids (tetrad))
____________ occurs before pachytene stage where it involoves a phyical exchange of chromosomes piecies that results in exchange of genetic information
Crossing Over
During ______________ the sister chromatids are randomly aligned in a double row
Metaphase of Meiosis 1
During _____________ the two dyad seperate within the tetrad from each other & goes to opposites poles on the cell
Anaphase of Meiosis 1
During ______________ & ___________ two new haploid cells formed
Telophase of Meiosis 1 & Cytokinesis
___________ is similar to Mitosis except mitosis begins with six dyads (12 chromosomes) (chromatids) & in ___________ begins with 6 chromsomes (chromatids) or 3 dyads
Meiosis 2
___________ produces two diploid daughter cells with six chromosomes each (12 chromosomes in total) & ___________ produces two haploid daughter cells with 3 chromsomes each (6 chromosomes in total)
Mitosis, Meiosis
The cells produced by __________ are genetically identical & the cells produced by __________ are not genetically identical
Mitosis, Meiosis