Pre-release questions Flashcards
Explain how drugs are approved from treatment of human disease?
- Phase 1: the drug is tested on a small group of healthy volunteers to test for safety
- Phase 2: the drug is tested on a small group of infected patients to determine how effective the drug is and what the most appropriate dose is. Double blind trail is used where neither the researcher or patient know which drug is a placebo and which is the working drug in order to remove researcher bias
- Phase 3: the drug is tested on a much larger group of patients to compare the effectiveness to other treatments.
What does the quote ‘the rise and fall of species’ allude to?
evolution due to natural selection
EQ. Suggest how natural selection could have given rise to certain adaptations (5 marks)
- selection pressures creates a struggle for survival
- such as predation
- mutations introduce new alleles into the population
- individuals with advantageous alleles are more likely to survive
- and therefore pass on advantageous alleles to their offspring
- so there will be an increased frequency of advantageous alleles in the population
How could the phrase ‘the rise and fall of species’ be linked to succession?
in succession the pioneer species are outcompeted by the next organism as they have altered the environment to allow the next organism to survive. for example mosses give way to grass as humus levels increase
EQ. Explain how ecosystems have developed on Surtsey since 1965 (6 marks)
- primary succession took place
- pioneer species took place
- these produced soil called humus
- and provided minerals and nutrients for plants to grow
- habitats and niches are provided for animals
- herbaceous shrubs and trees become established and climax community is established
State 2 ways Darwin was able to “popularize” his ideas on natural selection and what 2 obstacles did he have to overcome?
- Using evidence in his book O of S. Fossils, bones etc.
- Examples from farming.
- Main issue was religious backlash for linking humans with apes.
- Lack of fossil evidence in humans - incomplete fossil record.
What cellular processes lead to the “different shape beaks” seen in paragraph 3?
Meiosis creates variation through crossing over and independent assortment
EQ. Compare and contrast the results of mitosis and meiosis in the production of sperm cells from stem cells. (4 marks)
- both increase the number of cells
- mitosis results in 2 daughter cells while meiosis results in 4 daughter cells
- mitosis results in genetically identical daughter cells while meiosis results in genetically different daughter cells
- mitosis results in diploid cells while meiosis results in haploid cells
“Inflammation” paragraph 5 - How is inflammation employed by the bodies immune system
damaged blood vessels release histamines to cause vasodilation, which increases blood flow to the infected area and increases permeability to the infected area. antibodies, WBCs and plasma leak out into the infected tissue to fight the pathogen
Give 2 ethical arguments for using mice in investigating a new treatment regime - Paragraph 5
- causes suffering to animals
- better to carry out research on animals who will respond in a similar way to cancer and treatments
Why would a “small clinical trial” paragraph 6 be used before rolling out treatment to larger groups of patients
Small group to limit the danger. Allow for analysis of results before larger trials. To see if the drug is safe, the side effects and the safe doses used
Describe how “chemoresistance” - Paragraph 6 would proliferate in cancerous cells during chemotherapy treatment.
- selection pressures, creates a struggle for survival
- like the chemotherapy treatment
- mutations introduce new alleles into the population of cancer cells
- cancer cells with advantageous alleles (being chemoresistance) are more likely to survive
- and therefore pass on the advantageous alleles to their daughter cells when they multiply through mitosis
- so there will be an increased frequency of advantageous alleles (chemoresistant cancer cells) in the population
What are the two types of biotic competition Paragraph 3. Describe what each one is.
- intraspecific, between organisms of the same species
- interspecific, between different species
What are the importance of “lymph nodes” as part of the immune system
lymph nodes also contain lymphocytes which produce antibodies. The lymph nodes also remove bacteria and other pathogens.
Explain the process of speciation. - Paragraph 3
- Speciation is the development of new species from pre-existing species over time
- In order for speciation to occur two populations of the same species must be isolated from each other in some way
- So there can no longer be an exchange of genes between the two populations
Describe the difference between allopatric and sympatric speciation - Paragraph 3
- Allopatric is geographical isolation
- Sympatric is not geographical: -seasonal changes e.g different mating seasons -mechanical changes e.g changes to their reproductive body parts that prevent them from reproducing successfully -behavioral changes e.g changes in their courtship behaviour
In the UK in 2016, there were 525 048 deaths. Cancer caused 30.4% of all deaths. Throat cancer caused 5% of all deaths from cancer. Calculate the mean number of people who died of throat cancer per month in 2016.
- 30.4% of 525048= 159614.592
- 5% of ^^^=7980.7296
- that is for the whole year, for each month divide by 12 to get 665 to 3sf
A type of malignant tumour cell divides every 8 hours. Starting with one of these cells, how many tumour cells will be present after 4 weeks?
Assume none of these cells will die.
1.93 × 10^25
