B16, B17, B1 Flashcards
Chloroplast function:
Photosynthesis
Cell wall function:
Made of cellulose, gives the cell strength and support.
Vacuole function:
Contains cell sap (which keeps cell rigid) and controls cell water levels.
Cytoplasm function:
Jelly like substance where most chemical reactions take place
Nucleus function:
Contains DNA and controls the activities of the cell.
Cell membrane function:
Bodyguard of the cell.
Controls the movement of substances in & out of the cell.
Ribosome function:
Protein synthesis.
Mitochondria function:
Releases energy from aerobic respiration.
Magnification:
How large an image will appear in comparison to it’s actual size.
Resolution:
The clarity of objects that are very close together.
Magnification equation:
Image = Actual x Magnification
Eyepiece lens:
Lens closest to the eye.
Objective lens:
There are 3 lenses of different strengths which can be used to magnify the image more clearly.
Stage:
Where the slide is put. The clip holds the slide in place.
Diaphragm:
Controls the amount of light that goes on the slide.
Light:
Projects light onto the slide. Usually a mirror or electric bulb.
Base:
This is very heavy to keep the microscope from falling over.
Arm:
Holds the eyepiece lens above the stage.
Fine focus knob:
Used to focus the image so it is very sharp and clear.
Coarse focus knob:
Used to focus the image so it is very sharp and clear.
Prokaryotes:
Bacterial cells. Have a cell wall, cell membrane, genetic material, cytoplasm, plasmids and flagella.
Eukaryotes:
Cells with a nucleus (animal and plant cells).
Specialised cell examples:
- Sperm cell (carries genetic information to egg cell, tail allows it to swim).
- Red blood cell (transports oxygen required for aerobic respiration, no nucleus = more room for haemoglobin. Lots of haemoglobin = can carry more oxygen).
- Palisade cell (Photosynthesis; lots of chloroplasts = maximise absorption of light)
Stem cell:
An undifferentiated cell which can become any type of cell.
Embryonic stem cell, Adult stem cell, Plant stem cell
Embryonic stem cell:
- In the embryo.
- Can differentiate into any type of body cell.
- Use: Can treat any type of disease.
Adult stem cell:
- In bonemarrow.
- Can only differentiate in some cell types.
- Use: Bone marrow transplant.
Stem cell ethics:
Embryo For:
- Treatment for disease that previously had no cure.
- Many embryos naturally lost at this stage (abortion or discarded from IVF)
Embryo Against:
- Concerns that could cause cancer due to rapid growth.
- Moral, ethical and religious views against.
Adult for:
- Come from volunteers
- Less likely to become cancerous.
Adult against:
- Pre-specialised, EG blood stem cells make only blood cells.
Cell cycle stage 1:
- Cell grows in size
- Increase in number of organelles
- DNA duplicates
Cell cycle stage 2 (mitosis):
- Chromosomes line up in the middle.
- 1 copy of each chromosome is pulled to the side.
- Nucleus divides.
Cell cycle stage 3:
- Cytoplasm & cell membrane divide.
- To form 2 genetically identical daughter cells.
Food chain order:
Producers - make own food with photosynthesis.
Primary consumers
Secondary consumers
Tertiary consumers
Predators, prey & apex predators:
Predators = eat live prey.
Prey = gets eaten by predators.
Apex predators = do not get eaten by anything else.
Predator/prey relationship:
- Less predators than prey.
- Prey increases, predators increase.
- More food available so predators can reproduce more.
- Prey decreases, predators decrease.
- Less prey = less food = starvation.
Decay cycle:
- Decomposers return nutrients to soil.
- eg fungi, bacteria, insects/worms
- dead animals/plants and faeces decompose.
- key nutrients are recycled into the soil by decomposers.
- eg carbon and nitrogen.
Carbon cycle:
- Carbon in atmosphere absorbed by plants for photosynthesis.
- Plants consumed by animals - carbon bioaccumulated into their bodies.
- Animals and plants eventually die, and decomposing releases carbon back into atmosphere.
Water cycle:
Transpiration: Water taken in roots of plants is sent back into the atmosphere as water vapour.
Evaporation: Water evaporates from bodies of water, due to light energy from the sun.
Condensation: After evaporation and transpiration, the water vapour cools, forming liquid clouds.
Transport: When liquid clouds are formed, they can be pushed far distances by wind.
Precipitation: Rain, snow, sleet and hail fall from the clouds into the bodies of water and the land.
Surface runoff: Sometimes, when there is a large amount of precipitation, water runs along the earth to enter bodies of water.
Infiltration: Some water that falls is absorbed into the ground. It can then be stored in aquifers. These are underground, permeable rocks.
Biodiversity:
All species living in a certain ecosystem.
Human population explosion:
- less people dying
- healthier lifestyle
- no natural predators
- population increasing rapidly
land pollution:
landfill
litter
plastic (non biodegradable)
air pollution:
from fossil fuels
CO2 released in air contributes to greenhouse effect -> global warming
community:
all the organisms that live in a habitat
ecosystem:
the interaction of a community with non living parts of their environment.
global warming
ice caps melt -> rising sea levels -> loss of houses
environmental issues -> animals have to adapt
sulfid dioxide acid rain:
- sulfur dioxide dissolves in rainwater to make sulfuric acid.
- harms and kills plants
- damages statues and buildings
method to count number of daisies on a field:
use a quadrat and count number of daisies. repeat process at least 10 times. find the mean and multiply by total area of field.
what is a quadrat?
a 1m x 1m piece of equipment set down to count a number of organisms.
random sampling:
unbiased randomly placed quadrats to get a representative sample of the number of organisms in an area.
transect sampling:
tape measure/line used to mark a sample area. quadrat used at regular intervals to count number of organisms.
