BISC 100 - Lecture 21 : Cellular reproduction


Flashcards on BISC 100 - Lecture 21 : Cellular reproduction, created by Chelsi Souch on 10/08/2016.
Chelsi Souch
Flashcards by Chelsi Souch, updated more than 1 year ago
Chelsi Souch
Created by Chelsi Souch over 7 years ago

Resource summary

Question Answer
PROKARYOTES vs EUKARYOTES reproduction PROKARYOTIC CELL (e.g. Bacteria) Cells divide by BINARY FISSION (less complex) Chromosomes are replicated forming SISTER CHROMATIDS (identical copies of each chromosome) Sister chromatids assigned to daughter cells by MITOSIS
THE CELL CYCLE The cell cycle multiplies cells – The cell cycle consists of two major phases: INTERPHASE: Occupies the major portion of the cell cycle: G1 , S & G2 Mitotic Phase: Mitosis and Cytokinesis
During interphase: Chromosomes.... duplicate and cell parts are made
G1 phase of cell cycle Cell continues to grow • Organelles replicate (so that there is plenty to distribute among the daughter cells)
S phase (Synthesis phase) DNA replication Each chromosome forms TWO SISTER CHROMATIDS joined by a CENTROMERE
G2 phase cell cycle Cell continues to grow • Structures such as microtubules that are directly involved in cell division are synthesized and organized
MITOSIS Asexual reproduction of cells 2 daughter cells that are identical to the original cell (mutations: some variation) MITOSIS has 4 PHASES PROPHASE METAPHASE ANAPHASE TELEOPHASE
1. PROPHASE Centrioles duplicate and separate Mitotic spindle apparatus starts to form Chromosomes (already duplicated) condense (why is it necessary?) Nucleolus disappears Nuclear membrane breaks down Microtubules attach to the KINETOCHORE Duplicated chromosomes are pulled towards the center of the cell
2. METAPHASE CHROMOSOMES align at the center of the cell (METAPHASE PLATE) MITOTIC SPINDLES linking CHROMOSOMES to each pole are completed
3. ANAPHASE • Microtubule spindles contract • SISTER CHROMATIDS separate • They are pulled towards opposite poles
4. TELEOPHASE SISTER CHROMATIDS (now can refer to as non-duplicated chromosomes) reach the poles of the cell Chromosomes (non duplicated) de-condense Nucleus reforms CYTOKINESIS initiated
CYTOKINESIS Division of the cytoplasm into 2 new cells DIFFERENT between ANIMAL & PLANT cells CYTOKINESIS in an ANIMAL CELL Analogy: Fluid-filled balloon - string around it is pulled tight
What Is Cancer? Cancer is unrestrained cell growth and division caused by damage to genes regulating the cell division cycle. Ex. The “guardian Angel gene” p53 (tumor suppressor gene) • This gene plays a key role in G1 check point. The gene’s product p53 protein monitors the integrity of DNA. • If damage detected, halts the cell division and stimulates the activity of enzymes to repair the damage then allows to divide. • If can’t be repaired, p53 directs the cell to “commit suicide”, activating the cell’s apoptosis program.
Show full summary Hide full summary


Cellular Respiration
Kara Hauber
Physics 2a + 2b
James Squibb
Know the principles of electricity
Vito Martino
Maths Revision- end of year test
PHR SPHR Labor Union Terminology
Sandra Reed
OCR Physics P4 Revision
Dan Allibone
Biology B1
Kelsey Phillips
Romeo + Juliet (Themes)
New GCSE Maths
Sarah Egan
Meteorologia II
Adriana Forero
Core 1.3 Energy Generation, Storage and Use
T Andrews