Biology prelims

Prokaryotic Cell

Prokaryotic Cell

A cell with no membrane bound organelles, no nucleus and small size e.g. bacteria

Eukaryotic cells

Contain a nucleus and other organelles that are bound by membranes.

light microscope

microscope that uses a beam of light passing through one or more lenses to magnify an object

Fluorescence Microscope

An optical microscope that uses fluorescence and phosphorescence instead of, or in addition to, reflection and absorption to look at organisms on a slide.
Up to 2000x magnification.

Electron Mircroscope

Electrons is transmitted through the specimen, or bombards specimen with electrons

Cytoplasm

● consists of a liquid based background, in which there are dissolved chemical substances (e.g. ions such as chloride ions)
● Approximately 90 per cent of the cytoplasm is water

Ribosomes

-assist in making proteins
-found floating in the cytoplasm or attached to the rough er

Chlorophyll

A green pigment found in the chloroplasts of plants, algae, and some bacteria

cell membrane

the semipermeable membrane surrounding the cytoplasm of a cell.

Nucleus

-large spherical oval structure in the cytoplasm
-transparent and colourless
-functions include:storing DNA, cell growth, reproduction, ribosome production etc.

Mitochondria

-Powerhouse of the cell
-the site of ATP (energy) production through cellular respiration
-animals have more than plants as plants only use them at night

cellular respiration

Process that releases energy by breaking down glucose and other food molecules in the presence of oxygen

Chloroplast

- only found in plant cells
-where photosynthesis occurs
-contains chlorophyll

cell wall

-provides suppport and protection
-only found in plant cells
-lie on the outside of the cell membrane

fluid mosaic model

model that describes the arrangement and movement of the molecules that make up a cell membrane

Vacuole

-sac like structure
-stores water,ions,waste and proteins
-found in both plant and animal cells but is larger in plants

acitve transport

combine with a carrier and with the help of ATP diffuse against the concentration gradient and throught the tubular membrane.

Endoplasmic Reticulum

-forms a maze of passageways
-proteins and other materials are carried from one part of the cell to another.
-rough er: has ribosomes attached so has a rough outside

Lysosomes

-digest and remove waste from the cell
-contain digestive enzymes
-surrounded by a layer of lipids

Cytoskeleton

-Present in all cells
-complex network of interlinking filaments and tubules throughout the cytoplasm
-support shape and help facilitate movement

Golgi body

-found in most eukaryotic cells
-determines which proteins are allowed outside of the cell
-packages proteins into membrane bound vesicles to be sent out of the cell

Photosynthesis

Process by which plants utlisise light energy, trapped by chlorophyll

physical digestion

The mechanical breakdown of large food particles into smaller ones

Phospholipids

A molecule that is a constituent of the inner bilayer of biological membranes, having a polar, hydrophilic head and a nonpolar, hydrophobic tail.

Diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration.

Osmosis

Diffusion of water through a selectively permeable membrane

elimination of solid waste

Colon --> Rectum --> Neural signals to excrete --> peristaltic movement --> exit via anus

Endocytosis

process by which a cell takes material into the cell by infolding of the cell membrane

Exocytosis

Process by which a cell releases large amounts of material

surface area to volume ratio

Ratio of a cell's outside area to its internal volume.

light energy to chemical energy

photosynthesis

Waste

The products of cellular reactions that aren't required. Waste is discreted through diffusion, exocytosis or destroyed by enzymes

closed transport system

A type of circulatory system in which the transport fluid is always enclosed within blood vessels

Enzymes

Catalysts for chemical reactions in living things

unicellular organism

An organism made up of one cell.

colonial organism

a collection of genetically identical cells that live together in a connected group

Multicellular organisms

Organisms composed of many cells (Ex. tissue, humans, etc.)

Specialised cells

Cells that are adapted to carry out a particular function

structural adaptation

a physical feature of an organism's body having a specific function that contributes to the survival of the organism

chemical digestion

Process by which enzymes break down food into small molecules that the body can use

Autotroph

An organism that makes its own food

Heterotroph

An organism that cannot make its own food.

Alveoli

tiny sacs of lung tissue specialized for the movement of gases between air and blood

leaf structure

1. Epidermis
2. Mesophyll
3. Vein (Vascular Bundle/Vascular Tissue)

transpiration-cohesion-tension

The mechanism in which water molecules can travel against gravity and up the stem of a plant due to the properties of water.

Behavioural adaptation

what an organism does to survive in the unique conditions of its environment

Open transport system

blood is pumped by a tubular heart through a blood vessel and then out into the body cavity

divergent evolution

when two or more species sharing a common ancestor become more different over time

cardiovascular system

Blood vessels transport blood, which carries oxygen, carbon dioxide, nutrients, wastes, etc. The heart pumps blood.

plant vascular system

Water flows upwards through specialized tissues, while sugars are transported downward from the leaves where they are synthesized

biotic factors

All the living organisms that inhabit an environment

abiotic factors

Nonliving components of environment.

Predation

An interaction in which one organism kills another for food.

competition

the struggle between organisms to survive in a habitat with limited resources

symbiotic relationship

close interaction between species in which one species lives in or on the other

ecological niche

A specific role of a species within an ecosystem, including its use of resources, and relationships with other species.

physiological adaptation

a physical or chemical event that occurs within the body of an organism and enables survival

competitive exclusion principle

Ecological rule that states that no two species can occupy the same exact niche in the same habitat at the same time

convergent evolution

Process by which unrelated organisms independently evolve similarities when adapting to similar environments

Variation
Enrionmental pressure
Reproduction
Advantageous adaptions accumulate

VERA

natural selection

A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.

Biodiversity

the variety of life in the world or in a particular habitat or ecosystem.

Analyse

Identify components and the relationship between them; draw out and relate implications

Assess

Make a judgement of value, quality, outcomes, results or size

Critically (analyse/evaluate)

Add a degree or level of accuracy depth, knowledge and understanding, logic, questioning, reflection and quality to (analyse/evaluate)

describe

Provide characteristics and features

Evaluate

Make a judgement based on criteria

Outline

Sketch in general terms; indicate the main features (can do general dot points)

Identify

Recognise and name

Investigate

Plan, inquire into and draw conclusions about

Justify

Support argument or conclusion

Predict

Suggest what may happen based of available informatiion

Summarise

Express, concisely, the relevant details

Practical investigation of enzymes reactions

Using potatoes and adding in hydrogen peroxide to bubble up. Catalase, an enzyme breaks down hydrogyen peroxide into oxygen gas and water

Enzyme

A type of protein that speeds up a chemical reaction in a living thing

environment

the surroundings or conditions in which a person, animal, or plant lives or operates.

Ecosystem

A biological community of interacting organisms and their physical environment.

Competitive exclusion principle

This is when two animals have the same niche causing competition. This means that no two species can have identical niches

Distribution

The region where an organism is found

abundance

The number of individuals in the area

Pathogen

a bacterium, virus, or other microorganism that can cause disease.

Host

An organism on which a parasite lives.

Microevolutionary change

Small changes occurring within species, such as changes in allele frequencies.

Species

A group of similar organisms that can breed and produce fertile offspring.

Macroevolutionary change

cumulative change during thousands of small speciation episodes

Speciation

the formation of new and distinct species in the course of evolution.

Gradualism

The theory that evolution occurs slowly but steadily

Punctuated equilibrium

The theory that species evolve during short periods of rapid change

Population Genetics

the study of how populations change genetically over time

cell differentiation

the process by which cells become different types of cells

stem cells

unspecialized cells that are able to renew themselves for long periods of time by cell division

Stomata

Small holes in the leafs surface that lets out excess water vapour from the plant

upper epidermis

Transparent so light can pass through it to reach the palisade layer

palisade layer

Contains chloroplasts - where photosynthesis takes place

waxy cuticle

prevents water loss

spongy mesophyll

Loose tissue beneath the palisade layer of a leaf; has many air spaces between its cells

gas exchange in animals

The small sacks on the lungs which converts the high carbon dioxide in the blood to low carbon dioxide, going into through the rest of the body

Xylem

vascular tissue that carries water upward from the roots to every part of a plant

Pholem

type of vascular tissue that carries nutrients and food from place to place inside the cell

red blood cells

Blood cells that carry oxygen from the lungs to the body cells.