Biology - Cells and Classification Yearlies

What does MRS GREN stand for?

Movement; Respiration; Sensitivity; Growth; Reproduction; Excretion; Nutrition

What is movement in MRS GREN?

The ability to perform movement

What is respiration in MRS GREN?

A process that releases usable energy from food

What is sensitivity?

The ability to detect and respond to stimuli

What is growth?

A permanent increase or change in size or mass

What is reproduction?

The production of new organisms

What is excretion?

The removal of waste products

What is nutrition?

Obtaining and using nutrients or food

What is biodiversity?

The variety of living organisms

Why do scientists classify organisms?

To group organisms; identify species and understand relationships

What is taxonomy?

The scientific system of classifying organisms

What is binomial nomenclature?

The system of giving an organism a two-part scientific name

What are the two parts of a binomial name?

Genus and species

Why are scientific names useful?

They provide a more consistent international naming system

What is the classification hierarchy?

Kingdom; Phylum; Class; Order; Family; Genus; Species

What is the order of the seven taxonomic ranks?

Kingdom; Phylum; Class; Order; Family; Genus; Species

What is a vertebrate?

An animal with a backbone

What is an invertebrate?

An animal without a backbone

What are the three major mammal groups?

Monotremes; marsupials and placental mammals

What is a monotreme?

A mammal that lays eggs

What is a marsupial?

A mammal whose young develop further after birth

What is a placental mammal?

A mammal whose developing young are supported by a placenta before birth

What are the six commonly taught kingdoms?

Animalia; Plantae; Fungi; Protista; Bacteria and Archaea

What kingdom includes animals?

Animalia

What kingdom includes plants?

Plantae

What kingdom includes fungi?

Fungi

What kingdom includes many unicellular eukaryotes?

Protista

What broad group includes prokaryotic organisms?

Bacteria and Archaea

What is an adaptation?

A characteristic that helps an organism survive in its environment

What is a structural adaptation?

A physical feature of an organism

What is a physiological adaptation?

A way an organism's body functions

What is a behavioural adaptation?

Something an organism does that helps it survive

What is a structural adaptation of a kangaroo?

Strong hind limbs adapted for powerful hopping

What is a physiological adaptation of a kangaroo?

The ability to conserve water through specialised body processes

What is a behavioural adaptation of a kangaroo?

Seeking shade or changing activity patterns to reduce heat stress

What is a structural adaptation of eucalyptus?

Leaves with features that help reduce water loss

What is a physiological adaptation of eucalyptus?

Physiological processes that help it cope with dry conditions

What is a lignotuber?

A swollen underground structure that can store resources and help some eucalyptus regrow

What is an Indigenous classification system?

A knowledge system for grouping organisms based on culturally relevant observations and relationships

What is a dichotomous key?

A tool that identifies organisms using a series of two-choice decisions

What should you use in a dichotomous key?

Observable features

Why should dichotomous keys use observations rather than inferences?

An inference goes beyond what is directly observed

Is 'has wings' an observation?

Yes

Is 'can fly' always an observation?

No; it is an inference unless flight has actually been observed or established

What is a unicellular organism?

An organism made of one cell

What is a multicellular organism?

An organism made of many cells

What is cell theory?

All organisms are made of cells; cells are the smallest unit of life; all cells arise from existing cells

What is an undifferentiated cell?

A cell that has not yet become specialised for a particular function

What is a stem cell?

An undifferentiated cell that can develop into specialised cell types

What is a differentiated cell?

A specialised cell adapted for a particular function

How does a specialised cell's structure relate to its function?

Its features are suited to the job it performs

What is a red blood cell adaptation?

Its biconcave shape and haemoglobin help efficient oxygen transport

Why does a mature red blood cell lack a nucleus?

It has more space for haemoglobin and efficient oxygen transport

What is a neurone's main function?

Transmitting nerve signals

What structural feature helps a neurone transmit signals?

Long extensions such as an axon

What is a sperm cell's main function?

Delivering genetic material to an egg during fertilisation

What features help sperm cells move?

A streamlined shape and flagellum

Why do multicellular organisms need specialised cells?

Division of labour makes functions more efficient

Why are specialised cells interdependent?

They rely on other specialised cells and tissues to keep the organism functioning

What does a microscope do?

Magnifies objects too small to see clearly with the unaided eye

What is the stage of a microscope used for?

Supporting the slide

What are objective lenses used for?

Magnifying the specimen

What is the eyepiece?

The part you look through

What are focus knobs used for?

Making the microscope image sharp

What is the light used for?

Illuminating the specimen

How should a microscope be carried?

With two hands; supporting the base/body securely

What magnification should the outcome specify focusing with first?

40×

Why should you begin focusing with the specified lower magnification?

It gives a wider field of view and makes focusing easier

What should you never let the objective lens do?

Touch the slide

Which direction should the stage be moved for safe focusing?

Away from the objective lens

What should you do after focusing at the initial magnification?

Increase magnification as required and refocus carefully

What focus control is normally used at higher magnification?

Fine focus

What is field of view?

The diameter of the circular area visible through the microscope

What happens to field of view as magnification increases?

The field of view usually becomes smaller

How can you estimate cell size using field of view?

Divide field-of-view diameter by the approximate number of cells across

If the field of view is 600 µm and 4 cells fit across

what is the estimated cell size?

What is magnification?

How many times larger the image is than the actual object

What is the magnification formula?

Magnification = image size ÷ actual size

What is the formula for image size?

Image size = magnification × actual size

What is the formula for actual size?

Actual size = image size ÷ magnification

What must you do before using the magnification formula?

Convert measurements so the units are consistent

How many micrometres are in 1 millimetre?

1000 µm

What is the magnification triangle arrangement?

Image size is on top; actual size and magnification are underneath

What is an organelle?

A structure inside a cell with a specific function

What does the cell membrane do?

Controls what enters and leaves the cell

What does the cytoplasm do?

It is where many chemical reactions occur and organelles are suspended

What does the nucleus do?

Contains most genetic material and controls cell activities

What do mitochondria do?

Carry out aerobic respiration and release usable energy

What does the cell wall do?

Provides rigid support and protection

What does the vacuole do?

Stores cell sap/materials and helps plant cells maintain firmness

What do chloroplasts do?

Capture light energy for photosynthesis

What do ribosomes do?

Make proteins

Which cells have a cell wall?

Plant; fungal and bacterial cells

Which cells have chloroplasts?

Photosynthetic plant cells

Do animal cells have chloroplasts?

No

Do animal cells have a cell wall?

No

What is a prokaryotic cell?

A cell without a membrane-bound nucleus

What is a eukaryotic cell?

A cell with a membrane-bound nucleus

What type of cell is a bacterium?

Prokaryotic

What type of cells are plant and animal cells?

Eukaryotic