M5
What process produces gametes with half the chromosome number of the parent cell?
Meiosis
What molecule carries genetic information in most living organisms?
DNA
What is a disease-causing organism or agent called?
A pathogen
What is the body's ability to maintain a relatively stable internal environment called?
Homeostasis
Without counting. Do u know how many students, in total, do we have in Bio class?
11
What is the term for an organism's observable characteristics?
Phenotype
Name the 3 ways of gene mutation
substitution, insertion, deletion
What is the difference between a pathogen and a disease?
A pathogen is an infectious agent that can cause disease; disease is the condition resulting from disruption of normal body function.
What hormone lowers blood glucose concentration?
Insulin
Without counting. Do u know how many students, in total, do we have in Bio class?
11
During meiosis, what process exchanges sections of DNA between homologous chromosomes?
Crossing over
A mutation changes a DNA sequence but does not change the amino acid produced. What type of mutation is this?
Silent mutation
Name two major methods by which infectious diseases can be transmitted
include an example for each
Direct and indirect transmission
Why is maintaining homeostasis important when an organism is infected by a pathogen?
Maintaining stable internal conditions allows cells, enzymes and physiological processes to function effectively while the immune system responds to the infection.
You had 4 assessment tasks in HSC Bio. Which task, did your class, perform the best? (got the highest mean across)
AT1.
AT1 87%AT2 52%
AT3 59%
AT4 81%
Explain how genetic variation can influence the spread of an infectious disease through a population.
genetic variation --> better fit = advantageous --> survival + reproduce --> changing allele frequencies over generations
A DNA mutation changes a codon from one coding for an amino acid to a stop codon. What is the likely consequence?
A premature stop in translation
producing a shortened polypeptide that may be non-functional.
A population of bacteria is exposed repeatedly to an antibiotic. After several generations, a much larger proportion of bacteria survive. Explain this using natural selection.
Genetic variation = bacteria may already possess resistance.
The antibiotic selects against susceptible bacteria, while resistant bacteria survive and reproduce, increasing resistance in the population.
A person has a body temperature of 39°C. Explain how negative feedback mechanisms normally respond to an increase in body temperature. (use the SRCE sequence)
S:39°C
R:Thermoreceptors detect the change
C: the hypothalamus acts as the control centre
E: activates effectors (e.g. sweat glands and blood vessels
Result: increasing heat loss and reducing body temperature toward the set point.
Who have the highest (3) and lowest (1) attendance in Bio class?
Ethan, Aaron, Moni (98%)
Jason (75%)
A heterozygous individual for a dominant disorder has children with a homozygous recessive individual. What proportion of their offspring would be expected to have the disorder?
50%
Explain how a change in DNA can ultimately result in a change to phenotype.
A DNA sequence change --> alter a gene's expression or the amino acid sequence of a protein.
= alter protein structure/function, cellular processes
-->ultimately an observable characteristic.
A new infectious disease appears in a population after a pathogen undergoes mutation. Explain why mutation alone does not necessarily cause the disease to become widespread.
Mutation may produce variation, but spread also depends on factors such as transmission, host susceptibility, environmental conditions, pathogen virulence and population immunity.
A patient has chronically elevated blood glucose despite producing insulin. Explain one possible biological reason and identify the disorder.
The cells may have reduced sensitivity to insulin, resulting in insulin resistance. This is characteristic of T2DM.
If the entire class had to survive a zombie apocalypse using only their Biology knowledge, which student would be the first to go. and why?
(any reasonable answer)