Wrong in practice questions Flashcards
Emergent properties
Multicellular organisms show emergent properties: these are properties that exist due to many different components working together
Chlorophyll plays a role in what life function?
Nutrition
Centrifugation
A technique that separates substances based on their density
Functions of cholesterol in a cell membrane
- Reduces membrane fluidity by restricting the movement of phospholipids
- Increases membrane flexibility
- Redices the membrane’s permeability to hydrophilic substances
Why is blood classified as a tissue?
- Because it consists of different types of cells/because it consists of specialized cells
- It consists of red blood cells, white blood cells, and platalets
Explain how stem cells differentiate and hence specialise
using blood cells as an example
- Through selective gene expression stem cells (multi/unipotent) become specialised cells
- In the case of blood, these cells differentiate into red blood cells, white blood cells and platalets
Where are the stem cells needed to produce red blood cells located
In the bone marrow
- Which contains hematopoietic stem cells
Cohesion vs adhesion
- In cohesion, water molecules stick to each other while in adhesion, warter molecules stick to the polar surfaces of other molecules
- Cohesion explains water’s surface tension properties while adhesion explains capillary action
Good fats and bad fats
Good fats: cis unsaturated fats (mono/polyunsaturated)- lower blood cholesterol levels
Bad fats: trans unsaturated fats and saturated fats - raise blood cholesterol levels
Which cyclin increases to trigger the beginning of mitosis
B
Which techniques allowed scientists to falsify the Davson–Danielli model?
Freeze-etched electron micrographs and fluorescent markers
Light vs electron microscopes
The electron microscope has a higher resolution than the light microscope, and both can be used to observe non-living specimens.
DNA is loosely packaged by histones to form which molecule?
Chromatin
Note: Chromatin refers to a substance found in the cell nucleus that’s composed primarily of DNA and proteins. When cells divide, chromatin condenses to form chromosomes which split into two identical strands called chromatids.
Cyclin-dependant kinases
Cyclins bind to enzymes called cyclin-dependant kinases (CDKs) and activate them.
They attach to other proteins in the cell which triggers them to become active and carry out tasks specific to one of the phases of the cell cycle.
Osmolarity
Tissue osmolarity may be inferred by identifying the concentration of solution at which there is no weight change
Which part of the cholesterol molecule is hydrophilic?
Hydroxyl group
Note: cholesterol is made of a hydroxyl group, a steroid ring and a fatty acid tail
Recognition proteins are able to differentiate between substances. This is useful and helps them to trigger which type of response?
Immune
Lysosomes are often absent from plant cells and so a different organelle will take on the role of the lysosome. State the name of the plant cell organelle that is capable of doing this role.
Vacuole
Does homeostasis include maintaining osmotic pressure?
Yes
What is the difference between two alleles of a gene?
Their base sequence
Does cholesterol decrease membrane fluidity?
Yes.
Which cell component arose first during the formation of the earliest cells?
Plasma membrane
Haploid cells
Haploid cells are those that have only a single set of chromosomes.
- Gametes
Diploid cells
Diploid cells have two sets of chromosomes
- Somatic cells
In the G1 phase what happens to the number of chromosomes
Mitosis
In the G1 phase the number of chromosomes double.
Since this takes place in somatic cells, its important to note that it’s referring to diploid cells.
- Example: if a species hs a haploid number of chromosomes of 12, then it has a diploid number of chromosomes of 24 (which is the case of any of its somatic cells). Therefore in phase G1 it would have