Yr8 biology

Pollination

Pollination

is the transfer of pollen from one flower to the stigma of another

Where does fertilization occur in a flowering plant

the ovary

How is the pollen able to travel from the style to the site of pollination

It travels down a tube through the style to the ovary

What are the main forms of pollination and how are flowers adapted differently to each type

Wind - pollen is light weight and the anther and stigma are on the outside of the flower, making it easy for it to be blown by the wind

Animals - the pollen is sticky and sweet, the flower is brightly coloured and has an attractive smell, so that things like bees transfer pollen from one plant to another

Germination

is the process by which seeds develop into young plants, it requires warmth, oxygen and water

What are the main forms of seed dispersal and how are flowers adapted differently to each type

Wind - light weight seeds

Animal - sticky seeds and stick to animal fur

What are the different variables involved in a scientific investigation

control variables, Independent variable, Dependant variable

Accurate

how close a measurement is to the true value

Precise

close to other measurements

Repeatable

the same person can repeat the experiment and get similar results

Reproducible

others can repeat the experiment and get similar results

Limitations

a limit to what we can find out during an experiment

Interdependence

the state of being dependant upon one another

Ecosystem

a community of living organisms in one area

What do the arrows in a food web represent

the arrow starts at the prey and point towards the predator

Producer

use energy from the sun for photosynthesis (plants)

Consumer

an animal that eats other living organisms

predator

an animal which hunts and eats other animals

Prey

the animals that predators feed on

Apex predator

predators that are at the top of the food chain and don’t have any predators of their own

Biodiversity

the variety of living organisms in an area or ecosystem

Why is biodiversity important

without a wide range of living organisms we wouldn’t have healthy ecosystems

Conservation

reducing the human impact on an area

Describe different projects being carried out to preserve biodiversity

recycling reduces food, clothes and electrical waste, another way people are trying to do this is planting trees in the rainforest to try and help with the issue of deforestation

Organic farming

when farmers don’t use harmful chemicals like pesticides, on their crops

Intensive farming

producing as much food as possible by using chemicals to help with growth

How does the type of farming affect biodiversity

When using chemicals it will affect the plants and animals in the surrounding area lowering biodiversity, not using chemicals won’t affect the area nearly as much

Pesticides

kill or repel animals and other plant life, so that the crops grow faster without interference

Herbicides

destroy or control weeds and other unwanted plants

Fertilizers

can be either natural or artificial, and help with the growth of plants

Bioaccumilation

is the build up of toxic chemicals through a food chain

Why does bioaccumulation affect animals further up the food chain

because as the toxins build up each animal ingests more than the organism before it because each animals consumes multiple of what it is eating so something like an apex predator will end up with a lot more toxins in its system than those further down the food chain

Give some examples of bioaccumulation and its impacts

DDT - mammals exposed to DDT can develop liver tumours, and in general is highly toxic to all living creatures

Mercury - is generally made more toxic when consumed making it the most danger to apex predators like people

Quadrat

a frame used for sampling it sections of a small area, making it easy to count organisms within

Why is sampling done randomly

so that it isn’t biased towards a certain area or group

How can quadrats be put in a random location

use random numbers to choose the location

How can the population of an organism in a habitat be estimated using quadrats/random sampling

by counting the population in the area used for sampling and then x by the area of the habitat, will give you an estimate of how much the population is