Topic 1 Flashcards
Define movement in terms of the 7 life processes:
An action by an organism or part of an organism causing a change of
position or place.
Define respiration in terms of the 7 life processes:
The chemical reactions in cells that break down nutrient molecules and
release energy for metabolism.
Define sensitivity in terms of the 7 life processes:
The ability to sense external or internal stimuli and make appropriate responses.
Define growth in terms of the 7 life processes:
Permanent increase in cell size, cell number or dry mass.
Define reproduction in terms of the 7 life processes:
The ability to make more of the same organism. Offspring have to be fertile.
Define excretion in terms of the 7 life processes:
The ability to expel waste products, toxic materials from respiration or substances in excess.
Define nutrition in terms of the 7 life processes:
The ability to gain necessary energy by itself, for growth, development, and respiration.
4 features of plants:
- Multicellular
- Eukaryotic
- Cell wall = cellulose
- Autotrophs
Autotrophs?
Make its own energy (food)
Heterotrophs?
Does not make its own energy (food)
4 features of animals:
- Multicellular
- Eukaryotic
- No cell wall
- Heterotrophs
4 features of fungi:
- Multicellular
- Eukaryotic
- Cell wall = chitin
- Heterotrophs
What do classification systems aim to achieve?
They aim to reflect evolutionary relationships.
What is used as a mean of classification?
DNA sequencing.
What does it mean if a group of organisms share a recent ancestor?
They are more closely related and have base sequences in DNA that are more similar than those that share only a distant ancestor.
3 features of bacteria:
- Unicellular
- Prokaryotic
- Cell wall = peptidoglycan
3 features of proctists:
- Unicellular
- Eukaryotic
- Heterotrophs/Autotrophs
What are arthropods?
Jointed legs, segmented body sections, exoskeleton that’s made out of chitin.
Main features of insects:
3 body sections and 6 legs.
Main features of arachnids:
2 body sections and 8 legs.
Main features of crustaceans:
2 body sections and at least 10 legs.
Main features of myriapods:
Many body sections and 10 or more legs.
Main features of mammals:
- Fur/hair on skin
- Have a placenta
- Young feed on milk from mammary glands
- External ears (pinnas) visible
- Endothermic
What is a vertebrate?
Organisms that contain a backbone.
Main features of birds:
- Skin covered with feathers
- 2 legs and 2 wings
- Lay eggs with hard shells on land
- Beak
- Endothermic
Main features of reptiles:
- Dry, fixed scales on skin
- Lay eggs with rubbery shells on land
Main features of amphibians:
- Smooth, moist skin
- Adults usually live on land (so have lungs), larvae live in water (so have gills)
- Lay eggs without shells in water
Main features of fish:
- Loose, wet scales on skin
- Gills to breathe
- Lay eggs without shells in water
5 features of a monocotyledon:
- 1 cotyledon
- Parallel veins
- Vascular bundle arranged complexly
- Fibrous root system
- Floral parts usually in multiples of 3
5 features of a dicotyledon:
- 2 cotyledons
- Net-like veins
- Vascular bundles arranged in a ring
- Tap root
- Floral parts usually in multiples of 4 or 5
What is the function of the nucleas?
Contains genetic material. The nucleolus produces ribosomal RNA surrounded by nuclear envelope.
What is the function of the plasma membrane/cell membrane?
Keeps internal environments safe. Controls what goes in/out. Semi-permeable.
What is the function of the mitochondria?
Site of cellular respiration.
What is the function of chloroplasts?
Found in plants only, site of photosynthesis, contains chlorophyll.
What is the function of the cell wall?
Supports the cell shape.
What is the function of the vacuole?
Plants have one big central vacuole and animals have very small/absent vacuole. It is used as storage and maintains turgor pressure (turgidity).
What is the function of the lyosomes?
Sacs containing enzymes. Used to break down parts of a cell.
What is the function of ribosomes?
Site of protein synthesis (produces proteins). Associated with endoplasmic reticulum.
How are new cells produced?
New cells are produced by the division of existing cells.
What is the function of cytoplasm?
Made out of cytosol (fluid) and organelles. Site of chemical reactions.
What is a tissue?
A group of cells in a similar structure and function as a tissue.
What is an organ?
Group of different tissues with related functions.
What is an organ system?
A group of organs with related functions.
What is an organism?
A living thing that functions as an individual, made up of organ systems.
What is a cell?
The smallest unit of life. The structural and fundamental unit of life.
What is the formula to find the magnification of a specimen?
Magnification = image size/actual size
How many micrometers in a millimeter?
1000
Diffusion:
The net movement of particles from a region of their higher concentration to a region of their lower concentration (down a concentration gradient), as a result of their random movement.
Where does the energy for diffusion come from?
The kinetic energy of the random movement of molecules and ions.
What does diffusion allow through a cell membrane?
Some substances move in and out of the cells by diffusion.
What does diffusion do to help living organisms?
- Obtain many requirements
- Get rid of waste products
- Carry out gas exchange for respiration
What are the 4 factors that influence diffusion?
- Surface area
- Temperature
- Concentration gradient
- Distance
What is the role of water?
Used as a solvent in organisms to aid with digestion, excretion and transport.
Osmosis:
The net movement of water molecules from a region of higher water potential (dilute solution) to a region of lower water potential (concentrated solution), through a partially permeable membrane.
Plant cells in a hypertonic solution:
Net movement out of the cell. Cell becomes plasmolyzed due to the loss of water from vacuole, resulting in loss of turgor pressure and becomes flaccid.
Plasmolysis:
When the lack of water causes the cell membrane to peel off the cell wall, and shrink the cytoplasm.
What is a hypertonic solution?
A hypertonic solution contains a higher concentration of solutes compared to another solution.
Plant cells in a hypotonic solution:
Net movement of water into the cell. Cell increases in size and turgidity. The cell membrane pushes against the cell wall.
What is a hypotonic solution?
Contains a lower concentration of solutes compared to another solution.
Plant cells in an isotonic solution:
No net movement. It is in equilibrium, so there will be no change to the cell.
What is an isotonic solution?
Where the concentration of solutes is equal to another solution.
What are plants supported by?
The water pressure inside the cells, pressing outwards on the cell wall.
What is active transport?
The movement of particles through a cell membrane from a region of lower concentration to a region of higher concentration (against concentration gradient), using energy from respiration.
Why is active transport important?
It’s the process for movement of molecules or ions across membranes, including ion uptake by root hairs.
What are the role of protein carriers?
They move molecules or ions across a membrane during active transport.
