Cell Cycle, Division and organisation Flashcards
What happens in G0
Cells do not replicate, just respire and do normal metabolic reactions
Checkpoints (5)
At the end of each stage, checkpoints confirm if cell is able to progress
G1 checkpoint: cell size, nutrients, growth and DNA damage
G2: cell size, DNA replication, DNA damage
Spindle assembly checkpoint: At the metaphase stage in mitosis, this checks all the chromosomes are attached to spindle fibres
Failure at checkpoints lead to apoptosis.
Apoptosis
Programmed cell death
Homologous chromosomes (5)
- 23 chromosomes from each parent
Same; length Bonding pattern Type of gene Centromere position
Four phases of mitosis
Prophase
Metaphase
Anaphase
Telophase
Prophase (4)
Chromatin condenses to form chromosomes
Chromatids held by centromeres
Nuclear envelope disappears
Centrosomes form spindle fibres
Metaphase (4)
Chromosomes attach to spindle fibres
Motor proteins help with movement
(Protein E in centromere help pull chromosomes into 2)
Chromosomes line down metaphase plate
Anaphase (2)
Motor proteins pull on spindle fibres- s.f shorten
Chromosomes are split to either side of cell
Telophase (2)
Nuclear membrane constructed around chromosomes
Nuclear envelope constructed
Cytokinesis (2)
New cell membrane is formed
Cell splits to form two identical daughter cells
Interphase (name 6 processes that occurs in this phase)
All the processes before mitosis
- genetic material copied
- cell growth
- organelle replication
- ATP production
- proteins synthesis
- checking of DNA
Purpose of mitosis (4)
Cell replacement
Tissue repair
Organism/ tissue growth
Asexual reproduction
Location of mitosis
Every cell but gametes
Product of mitosis
2 genetically identical
diploid daughter cells
Purpose of meiosis
Creates gametes in animals
Creation of spores in fungi and plants
Location of meiosis
Reproductive organs in animals
Product of meiosis
4 haploid daughter cells
genetically unique
Mix of DNA from both parents
Events that occur in G1
Cell growth
Protein synthesis
Organelles duplicate
Transcription
Features and function of neutrophils (4)
Ingests and destroy invading microorganisms
Lobed nucleus; squeeze through small gaps and vessels
Granular cytoplasm; contains lysosomes which release enzymes to attack pathogens
10-14 micro meters
Erythrocytes functions and structure (5)
Carries oxygen in the blood.
Haemoglobin; binds to oxygen
No nucleus; more space for haemoglobin
Bio concave; greater SA:V ratio
Flexible; squeeze through tiny capillaries
Squamous epithelium function and features (2)
Flat, single layered, smooth cells; covers a large area
Basement membrane; collagen and glycoproteins that binds to connective tissue. Used for cell signalling and cell adhesion.
Thin: short distance for diffusion