Biodiversity Flashcards
4.1 Know that over time the variety of life has become extensive but is now being threatened by human activity
There has been extinction going on due to human activities such as hunting. Forests and other ecosystems are futher used for human living and for other usage to support for living condition of humans. This has caused the animals to lose their habitat, causing an increase in the risk of extinction.
4.2i) Understand the terms biodiversity = and endemism
Biodiveristy is the study of the variation of species that exist in a particular region.
It can be checked by the number and range of different ecosystems and habitats, the number of species and their relative abundance and the grnetic variation within each species.
Endemism is when a specie only exist in a particular geographical region and cannot be found anywhere else. They have higher risk of extinction due to them only existing in a single geographical region
ii) Know how biodiversity can be measured within a habit using species richness and within a species using genetic diversity by calculating the heterozygosity index (H)
Species richness is the simplest way to measure the biodiversity. It is done by coutning the number of species present in a given habitat. This gives us an easy comperison between the biodiversity of two different habitat.
The heterozygosity index formula collect the number of heterozygots in the area and the number of individual in the population.
If there is a higher proportion of heterozygotes in a popuulation, there is a higher genetic diversity.
iii) Understand how biodiversity can be compared in different habitats using a formula to calculate an index of diversity using the equation
The diveristy index is a way of calcuation a quantitave score for biodiveristy that takes account of both species richness and speices evenness. The formula can be used to compare the biodiversity of different habitats.
4.3) UNderstand the concept of niche and be able to discuss expamples of adaptation of organisms to their environment (behavioural, physiological and anatomical)
A niche is the way an organism exploit (uses) its environment. All the organisms in a habitat has their own niche. If there’s two species that has the same species, they will compete against each other. The organism that is better adapted to the environment will over compete the other species.
4.3) UNderstand the concept of niche and be able to discuss expamples of adaptation of organisms to their environment (behavioural, physiological and anatomical)
There are three ways in which the organisms adapt to their environemts :
(1) Behavioural adaptations (actions)
This adaption is processed out by an actions an organism do to help them survive or reproduce.
Eg: The agouti bury Brazil nuts, this is a behaviour that will ai their vurcial by providing a furture food source.
(2) Physical adaption (internal)
This is where the internal workings of organisms help them to survive or reproduce.
Eg: THe Danish scurvy grass spread inland by the use of salt on icy road. Due to this, they have high salt concentrations which allow them to occupy a newly created niche unavailable to other inland plants.
(3) Anatomical adaptations (observable structure)
This adaption is where we can see when we observe or dissect an organism.
Eg: The bodies of bumblebees show agaptations used to collect nectar and pollen. Each has a long tongue through which it can suck nectar (sugary solution) from flowers. There are also bumblebees that has the long tongue than other, which allow them to feed from different flowers.
4.4) Understand how natural selection can lead to adaptation and evolution.
Natural selection is where the organisms that is well adapted to the environemnt. A species that has the greatest chance of surviving under any type of pressure.
Evolution is the change in allele frequency in a population over time (generation). The changes in the allele is the natural selection as it is done to keep the species more adaptied to the environment, highen the chances of the species surviving.
4.5i) understand how the Hardy-Weinberg equation can be used to see whether a change in allele frequency is occuring in a population over time
Hardy-Weinberg equation make use of the frequency of homozygous dominat individual (p^2), frequency of heterozygous individuals (2pq) _ frequency of homozygous recessive individuals (q^2). This allow them to forsee the difference in the allele frequency and predict the changes that is going to occur in the future.
FORMULA : p^2 +2pq + q^2 =1
4.6i) Understand the classification is a means of organising the vareity of life based on relationships between organisms using differences and similarites in phenotypes and in genotypes, and is built around the species concept
4.6ii) Understand that classification is a means of organising the variety of life based on relationships between organisms using differences and similarities in phenotyes and in genotypes and is built around the species concept.
The classification of the species are based by the evolutionary origins and the relationships. They can be group through genus, family, order, class, phylum, kingdom and domain.
There are no overlap between groups which allow the scientists to differentiate and classify which group they belong to.
Due to the appearance can be very deciving, the use of DNA sequencing has been used.
4.6iii) understand the process and importance of critical evaluation of new data by the scientific community which leads now taxonomic grouping, including the 3 domains of all life based molecular phylogeny, which are bacteria, Archea Eukaryotae
The procedures done first to publish a scientific journal as a peer review. Held a science conference and publish it on the internet.
When the first time Woese proposed the findings, he wasn’t taken seriously between the scientific community and were instead ignored. He also wasn’t interested in holding a large conference which doesn’t allow him any moment of counter argue.
4.7 Know the ultrastructure of plant cells (Cell walls, chloroplasts, amyloplasts, vacuole, tonoplast, plasmodesmata, pits and middle lamella) and be able to compare it with animal cells.
Cell wall - Is the structural support of the cell (provide shape)
Choloroplast- Surrounded by double membrane and are the main site of photosynethesis
Amyloplasts - they are mainly responsible for storing starch and converting the stored starch into glucose when needed.
tonoplast- is the selectively permeable membrane that control what enters and leave the vacuole.
plasmodesmata - they transport substances between plant cells and allow cell to cell communication.
Pits - they also transport substances between cells.
middle lamella - they provide the structure and stability of the plant.
4.8 Be able to recognise the organelles in 4.7 from electron microscope (EM) images.
Cell wall is on the outer part of the plant cells.
Chloroplast are usually presented in green color or are either usually in a big shape.
Amyloplst has small pores on it.
Vacuole is the organelle that takes the most space in the cell.
Tonoplast is the membrane of vacuole.
Plasmodesma is the opened entrance which allow elements to flow from one cell to another.
Pits is the small area near the plssmodesma.
Middle lamella is the connection between the two plant cells.
4.9 Understand the structure and function of the polysaccharides starch and cellulose, including the role of hydrogen bonds between beta glucose molecules in the formation of cellulose microfibrils.
A plant strength is provided by the thin layer of the cellulose walls and the elements that glue them together.
Cellulose is a polysaccharide.
It is a type of glucose by is formed from the condensation reaction between the -OH group on the first carbon of one glucose and the -Oh on the fourth carbon of the adjacent glucose links to the two glucose molecules.
Cellulose is a long unbranched molecule due to this. There are bonds formed between 1,4 and 1,6 glycosidic.
4.10 Understand how the arrangement of cellulose microfibrils and secondary thickening in a plant cell wall contributes to the physical properties of xylem vessels and their location within stems through a light microscope.
The cellulose microfibrils are arranged in a bulletin of 60 to 70 cellulose molecules. They are wound in a helical arrangement around the cell and stuck robbers with a polysaccharide glue.
The arrangement of the cellulose micro fibrils are built in a matrix like shape with layers of cellulose microfibrils laid down in different angles which causes it to be very strong.
4.11 Know the similarities and differences between the structures, position in the stem and function of sclerenchyma fibres in plant fibres that can be exploited by humans.
The sclerenchyma fibers are made of long hollow plant cells which is due to their cell contents dying. They are very strong which can be used to make ropes and fibrils.
Stems have cells that are no dead which contain vascular tissue. It contain xylem vessels and phones sieve tubes,
