Revision Flashcards
Adaptations of an animal from a cold climate
Thick layers of fat Thick layers of fur A small surface area to volume ratio A greasy coat Short limbs Small ears
Adaptations of plants from a dry environment
Ability to store water in stems and leaves Long root systems Waxy coating to reduce water loss Spines to discourage animals Slower growing requires less energy
Adaptations for plants from a salty environment
Leaves with glands to excrete salt Tolerance with the storage of salt Far-reaching exposed roots Roots to stop the intake of salt Ability to turn the leaves to reduce surface area of the leaf
Resources which animals compete for
Space Mates Nests Food Water
Resources which plants compete for
Mineral salts
Space
Sunlight
Water
Physical features of predator species
Forward location of the eyes Acute sense of smell Acute sense of hearing Strong jaw Good stamina Strong hind legs
Behavioural features of prey
Move quietly Move in herds Good stamina Ability to pick sheltered nesting area Solitary
Physical features of prey
Quick
Strong hind legs
Acute senses
Good stamina
Behavioural features of predators
Move quietly Move in herds Trickery Lure them Good stamina
Seed Dispersal
Gliders (winged seed)
Helicopters (slow to descend/carried by air currents/spin)
Cotton seeds and fruit (dense mass of tiny seeds)
Tumbleweed (light weight/ pushed by winds/ scatter seeds)
Parachute (fragile/light weight/airborne at the slightest gust of wind)
2 reporoductive organs in plsnts
Anther and stigma
Why are pollinators attracted?
Nectar
Smell
Colourful
What is a pathogen?
A pathogen is a micro-organism that causes disease
Bacteria
Single-celled organisms
Can be harmful or helpful
Can cause disease
Reporoduce inside the body to produce toxins whichcause symptoms
Viruses
Non-living particles (made of protein and DNA)
All cause disease
Take over cells and turn em into virus factories
You feel ill because cells burst and die
Fungi
Can be single-celled or multicellular
Can be harmful or helpful
Some can cause disease
Protozoa
Single-celled organisms
Some can be harmful or helpful
Some can cause disease
Most are not pathogens, but some are
Vector
Infectious agent spread to humans by blood-sucking insects (vectors)e.g. mosquitoes, ticks, fleas
Insect feeds on an infected animal then feeds on human and passes the germ into the blood stream
Direct and Indirect Contact
Direct contact is, for example, touching an imfected person or being bitten by a diseased animal
Indirect contact is, for example, touching a surface (doorknob/work surface) contaminated with an infectious agent
Ingestion
Infectious agent spread through contaminates food or water
E.g. If someone does not wash their hands before preparing food or faeces in water (swimming pool/lake)
Airborne
Tiny mucus droplets: travel long distances, remain suspended or carried in the air for hours or days. Soread through coughing and sneezing
What is immunity?
The state of being immune from or insusceptible to a particular disease or the like.
What are memory cells?
Memory cells are a type of white blood cell that can respond quickly when it meets a microorganism for the second time. They produce the right antibody for the particular microorganism and antigens and destroy it before you feel unwell. This is described as being immune to a disease.
What is a vaccine?
A dead or inactive the pathogen entering the body to stimulate white blood cells. They produce the correct antibodies which fit with the antigens to kill the disease. Memory cells are created and if the patjogen enters again the body knows how to react. The problems occur when there are different versions of the pathogen e.g. flu and cold viruses, meaning you have to go through thr process of natural active immunity again.
How do vaccinations prevent epidemics?
If less people are able to get the disease, there is less people for those who can catch it.
What is herd immunity?
The immunity or resistance to a particular infection that occurs in a group of people or animals when a very high percentage of individuals have been vaccinated or previously exposed to the infection.
What is antibacterial resistance?
Over time, bacteria can become resistant to certsin antibiotics. This is an example of ‘natural selection’. In a large population of bacteria, there may be some that are not affected by the antibiotic. These survive and reproduce, creating more bacteria that are not affected by the antibiotic.
How does antibacterial resistance increase?
Random changes or mutations occur in the genes of individual bacteria
cells
Some mutations protet the bacterial cells from the effects of the antibiotic
Bacteria without the mutation die or cannot reproduce with the antibiotic present
The resistant bacteria are able to reproduce with less competition from normal bacteria.
More common if people: don’t finish the full course of medicine/ use medicine unnecessarily.
How does your body react to a cut?
Stage 1: the skin is broken
Stage 2: platelets form a mesh of fibres across the surface of the cut
Stage 3: red blood cells get trapped in the mesh
Stage 4: the clot dries - a scab. New skin grows underneath
How is cilia and mucus a successful defence mechanism?
Pathogens get trapped in the mucus and the cilia mexican wave them out
What is a Phagocyte?
Eating cell
What is a Lymphocyte?
Pathogens contain certain chemicals that are foreign to the body and are called antigens. Each lymphocyte carries a specific type of antibody - a protein that has a chemical ‘fit’ to a certain antigen. When a lymphocyte with the appropriate antibody meets the antigen, the lymphocyte reproduces quickly, and makes many copies of the antibody that neutralises the pathogen.
Why are you immune after vaccination?
The lymphocytes know which antigen is needed to destroy the pathogen and can respond quickly.
How does your body react to pathogens?
Lymphocytes recognise the antigens as non-self. They produce antibodies and the antibodies attach to pathogens, if they are the right with their antigens. The process of killing the pathogens is longer, during this time you become ill?
What is active natural immunity?
You have made your own antibodies and memory cells from getting the disease
What is artificial active immunity?
You have made your own antibodies and memory cells from a vaccination.