Genetics and Variation Flashcards
What are the four stages of cell eukaryotic cell division?
Prophase, metaphase, anaphase, telophase
What is chromatin
The unravelled form of chromosomes
What is a chromosome?
A long DNA molecule associated with another protein (usually a histone protein)
How many centromeres in one chromosome?
1
What is a homologous pair of chromosomes?
Unidentical chromosomes with DNA that codes for the same features in the same place.
What are the 4 stages of the cell cycle (not PMAT) and what do they stand for?
G1,growth phase 1
S, synthesis phase
G2, growth phase
M, mitosis
What happens in the four stages of the cell cycle (G1, S, G2, M)
G1- cell grows, normal processes occur
S- chromatids replicate
G2- cells build up ATP, DNA is screened
M- PMAT
What are the 4 stages of mitosis
Prophase
Metaphase
Anaphase
Telophase
What happens in Prophase? (4)
1- chromosomes condense
2- centromeres move to poles
3- spindle fibres form
4- nuclear envelope breaks down
What happens in Metaphase? (3)
1- centrosomes arrive at opposite poles
2-chromosomes line up at equator
3- spindle fibres attach to centromeres
What happens in Anaphase? (2)
1- sister chromatids separate at centromere
2- spindle pulls chromatids to opposite ends of cell
What happens in Telophase?(3)
1- chromosomes decondense back into chromatin
2- nuclear envelope & nucleolus reform
3- spindle breaks down
What happens after Mitosis? (Name and what actually happens)
Cytokinesis, the cytoplasm divides
What controls cell division?
Proteins called cyclins
What controls cell division?
Proteins called cyclins
What type of tumour does not lead to cancer?
Benign tumours
How do malignant tumours spread?
Through blood or lymph vessels
What is the process of a tumours spreading called, and what type of tumour is formed?
Metastasis forms a metastatic tumour
What three ways can tumours cause damage?
Pinch blood vessels
Outcompete organs for nutrients
Damage organs
How do prokaryotes divide (name)
Binary fission
What is the process of binary fission?
DNA replicates
Plasmids replicate ( more than once)
Cytoplasm divides
How does viral replication work?
(4)
Attachment proteins attach to host cell surface markers
Virus injects nucleus acid into host cell
The host cells ribosomes produce new viral particles
Virus is released through budding or bursting
How do viruses cause damage?
Reduce/ inhibit normal cell function
What two enzymes do viruses contain and what do the enzymes do?
Reverse transcriptase converts RNA into DNA to be inserted into genome
Integrate inserts viral DNA into host cells genome
What are the two ways of release in viral replication and what occurs in each
In budding the virus leaves through membrane and becomes enveloped (takes the membrane with it)
In bursting the cell bursts and all cells leave at once producing an unenvoloped virus
What molecule maintains fluidity in the plasma membrane
Cholesterol
What are intrinsic proteins
Proteins that span the entire width of the plasma membrane
What can independently diffuse across the plasma membrane
Small, non polar molecules
What type of diffusion do channel proteins help with
Facilitated diffusion
What two types of proteins are used for facilitated diffusion? And which one uses ATP?
Channel proteins & carrier proteins
Carrier proteins require ATP
What is the water potential of pure water?
O
What is the definition for osmosis?
The net movement of water across a partially permeable membrane from an area of low to high solute concentration
What are the channel proteins for water called?
Aquaporins
What is the equation for water potential
Water potential= solute potential - pressure potential
What is a hypertonic solution
Greater water potential than inside the cell
What type of solution has the same water potential outside the cell as inside of the cell
Isotonic solution
Hypertonic solution definition
Lower water potential outside of cell than inside of the cell
What is the definition of active transport
Movement of molecules across a cell membrane from a LOWER CONCENTRATION TO A HIGHER CONTRACTION using energy from ATP
What is the definition for Co-Transport and does it use ATP?
When the transport of one substance is coupled by the transport of another substance.
It does not require ATP
What is the example of co-transport?
The co-transport of glucose with the facilitated diffusion of sodium ions
What is the prices for the movement of glucose from the small intestine to the blood through epithelial cells
1- glucose and sodium ions travel into cell through carrier proteins
2- carrier protein moves sodium ions into blood by active transport
3- glucose diffuses into the blood through channel protein
