Cell Cycle Flashcards
Mitosis - what are the 3 stages of interphase include gap phase
G1 = growth of cells, organelles and increased number of organelles, synthesis of proteins
Synthesis = cell replicates dna, ready to divide by mitosis
G2 = where energy stores (atp) are increased
Gap phase (G0) = nesting phase where damaged cells are killed
What are the reasons for G0/ gap phase
- differentiation - cell becomes specialised to specific functions
- if dna has been damaged it undergoes cell arrest where that damaged one doesn’t replicate
Mitosis - chromosome structure
Only visible during cell division
Each chromosome consist of 2 chromatids joined along length of centromere
Genetic info Carrie on each chromatid is identical
Mitosis - what happens in interphase
DNA chromosomes replicate as chromatin
DNA checked for errors
Protein synthesis
ATP production
Mitosis - what happens in early prophase
Chromosomes become distinct - coil, shorten , thicken
Centrioles divide
Nucleolus more prominent
Mitosis - what happens in late prophase
Chromosomes distinct
Consist of 2 chromatids joined at centromere
Centrioles migrate to opposite end of cell
Nuclear envelope disintegrates
Mitosis - what happens in metaphase
Chromosomes align at metaphase plate (middle)
Spindle fibres attach to centromere
Mitosis - what happens in anaphase
Centromere splits causes chromatids to separate
Spindle fibres contract pulling it part
Mitosis - what happens in telophase
Chromatids uncoil and decondence when at opposite ends
Nuclear envelope reforms
Mitosis - what happens in cytokinesis
Cytoplasm divides
Produces 2 daughter cells that are genetically identical
Meiosis - what is crossing over
Homologous pair of chromosome swap part of their genetic material
What are homologous chromosomes
Chromosomes of same size, genes and occur in same position
Meiosis - what’s independent assortment
Chromosome from each pair randomly allocate to the daughter cell
What are stem cells
Unspecialised cells that can specialise or differentiate
What are specialised cells
Adapt to a specific functions and grouped into tissue which combine to make organs
What is tissue
Collection of differentiated similar cells that have specialist functions
Function of erythrocytes (red blood cells) and their adaptations
- carry oxygen from lungs to respiring cells
- small and flexible to fit
-no nucleus or organelles to carry more - bi concave shape - good SA:V ratio
Spermatozoa function and adaptation
Fertilise egg
Lots of mitochondria to swim
Flagella to help motility
Neutrophil function and adaptation
Ingest invading pathogens, type of white blood cells
Attracted and travel to infected sites
Have lysosome to break down pathogen
Epithelial cells function and adaptation
Create barrier between inside and outside of the body
Have cilia
Flattened in shape
Lots of mitochondria
Xylem function and adaptation
Transport water and nutrients from roots to leave/stem
Hollow tubes
No cytoplasm or organelles
Have cellulose
Phloem function and adaptation
Transport sugars throughout plant
Sieve tubes
Companion cell
Sieve plate
Few organelles
What are totipotent and what can they develop into
They’re young embryonic stem cells and can develop into any cell type
What are pluripotent and what can they develop into
They’re older embryonic stem cells and can become most cell types
What are multipotent and what can they develop into
They’re adult stem cells and can develop into multiple cell types but only produce cells with related function
