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
What feature allows transport of glucose in blood plasma?
It is polar.
What are alleles?
Various forms of a gene with slight differences in their base sequences.
What is cellulose
Cellulose is a polysaccharide made up of long straight chains of beta-glucose molecules. These long, straight chains are joined by hydrogen bonds in order to provide stability and strength to the molecule.
- Tertiary structure
Glycosidic bond
A covalent bond.
- Connects a carbohydrate (sugar) molecule to another group, which might be another carbohydrate or not
Can plants absorb oxygen for respiration?
Yes.
For example, at night.
Cellulose structure and what is it made of
Unbranched chains of beta-glucose
Starch (amylopectin) and glycogen structure and what is it made of
Branched
Alpha-glucose
Which process occurs in both aerobic and anaerobic cellular respiration?
Glycolysis
What is measured by a respirometer?
The rate of respiration
In sex linked diseases, when are females carriers?
When they are heterozygous for a recessive disease
Is there a correlation between the chromosome number and genome size?
No
How many copies of each gene does bacteria have?
One
Which enzyme is used to convert mRNA into cDNA during gene transfer?
reverse transcriptase
What name is given to the short strands of DNA that anneal to the target DNA sequence in order to identify the sequence of DNA to be copied?
Primers
Why is it not possible to be a carrier of Huntington’s disease?
Huntington’s is a dominant disease
A mutation in the CFTR gene causes cystic fibrosis. Which protein does this gene code for?
A chloride channel in the mucous membrane.
The nuclear explosion at Chernobyl power station in 1986 caused an increase in cancers in surrounding areas. Which cancer was seen to increase dramatically in children following the explosion?
Thyroid
Why does the proteome of a species contain a larger number of proteins than can be coded for by the genome of the same species?
Because there is differential and development-specific expression of genes. Explanation: Some genes can code for several proteins that are expressed during the various stages of development.
Does having more genes mean a larger genome?
Yes
How do greenhouse gases contribute to global warming?
They prevent radiation from the Earth escaping into space.
Which process increases the size of the carbon sink in oceans?
Photosynthesis
What does it mean if the value of the chi-squared test is below the critical value?
The distribution of one species is independent from the other.
Calcification
The process by which some marine organisms (shells and molluscs) build an exoskeleton or shell out of calcium carbonate.
In what conditions is peat formed?
Waterlogged, acidic and anoxic.
Methane can be oxidised in the atmosphere. State the two products of methane oxidation.
Carbon dioxide and water
In a diagram showing a pyramid of biomass there may be another block on the primary consumer level in addition to herbivores. What does this additional block represent?
Decomposers
Which greenhouse gas traps 20 times more heat than carbon dioxide per molecule?
Methane
In a food chain energy can be lost in a number of ways. What percentage of energy is usually lost between trophic levels?
90%
Which kind of DNA may provide the best molecular clock for constructing a cladogram of several species whose common ancestor became extinct billions of years ago?
DNA coding for ribosomal RNA.
- Ribosomal genes are the most conserved genes.
Which factors would affect whether a species evolves?
- Environmental change
- Inbreeding: reduces genetic variation
- Phenotypic variation
When B cells are activated, they divide by…
mitosis
Which kingdom of organisms produces and secretes the most types of antibiotics?
Fungi
Which processes within bacteria that are targeted by antibiotics?
- Membrane formation
- Ribosome function
- DNA replication
Emphysema is a chronic lung disease that may be caused by smoking tobacco. It causes shortness of breath (wheezing), coughing and fatigue. What changes to alveoli may cause these symptoms?
Larger alveoli with thicker walls
Ventilation rate vs tidal volume of lungs
The ventilation rate is defined as the number of breaths taken per minute, while the tidal volume is the volume of air that is transported into and out of the lungs.
A cell that is dividing too rapidly may have lost its ability to enter which part of the cell cycle?
G1
State the name of the molecule that CDKs attach to proteins in order to activate them.
phosphate group
DNA sense strand = the sequence of RNA except t is replaced with U.
The anti sense strand would be the opposite
Does amylase perform hydrolysis?
Yes
