1. Characteristics & Classification Of Living Organisms Flashcards
Movement definition
an action by an organism or part of an organism causing a change of position or place
Respiration definition
the chemical reactions that break down nutrient molecules in living cells to release energy for metabolism
Sensitivity definition
the ability to detect or sense stimuli in the internal or external environment and to make appropriate responses
Growth definition
a permanent increase in size and dry mass by an increase in cell number or cell size or both
Reproduction definition
the processes that make more of the same kind of organism
Excretion definition
the removal from organisms of toxic materials, the waste products of metabolism (chemical reactions in cells including respiration) and substances in excess of requirements
Nutrition definition
the taking in of materials for energy, growth and development; plants require light, carbon dioxide, water and ions; animals need organic compounds, ions and usually need water
Species definition
A species is defined as a group of organisms that can reproduce to produce fertile offspring
In what ways can species be classified into groups
These species can be classified into groups by the features that they share
How are organisms classified in a binomial system?
He named organisms in Latin using the binomial system where the scientific name of an organism is made up of two parts starting with the genus (always given a capital letter) and followed by the species (starting with a lower case letter)
What is the sequence of classifications for the binomial system?
Kingdom, Phylum, Class, Order, Family, Genus, Species
Why do organisms share features?
Organisms share features because they originally descend from a common ancestor
In what way did organisms use to be classified?
Originally, organisms were classified using morphology (the overall form and shape of the organism, e.g. whether it had wings or legs) and anatomy (the detailed body structure as determined by dissection)
What allowed us to classify organisms more accurately?
As technology advanced, microscopes, knowledge of biochemistry and eventually DNA sequencing allowed us to classify organisms using a more scientific approach
What does it show if the base sequences in the DNA of two species are similar?
Studies of DNA sequences of different species show that the more similar the base sequences in the DNA of two species, the more closely related those two species are (and the more recent in time their common ancestor is)
What do the cells of all living organisms contain?
The cells of all living organisms contain the following:
Cytoplasm
Cell membrane
DNA as genetic material (either found in the nucleus or free in the cytoplasm)
ribosomes
enzymes
Where can enzymes be found in a cell and what are they used for?
Enzymes for respiration (in many, but not all types of cells, found in mitochondria
What is the first division of living things in the classification system?
the five kingdoms
What are the 5 kingdoms of classification?
Animals
Plants
Fungi
Protoctists
Prokaryotes
What are the main features of all animals?
they are multicellular
their cells contain a nucleus but no cell walls or chloroplasts
they feed on organic substances made by other living things
What are the main features of all plants?
they are multicellular
their cells contain a nucleus, chloroplasts and cellulose cell walls
they all feed by photosynthesis
What are the main features of all fungi?
usually multicellular
cells have nuclei and cell walls not made from cellulose
do not photosynthesise but feed by saprophytic (on dead or decaying material) or parasitic (on live material) nutrition
What do the cell walls of fungi cells contain?
chitin
What are the main features of all protoctists?
most are unicellular but some are multicellular
all have a nucleus, some may have cell walls and chloroplasts
meaning some protoctists photosynthesise and some feed on organic substances made by other living things
What are the main features of all prokaryotes?
often unicellular
- cells have cell walls (not made of cellulose) and cytoplasm but no nucleus or mitochondria
What is the cell wall of prokaryotes made from?
peptidoglycan
What are the 5 classes of vertebrates?
mammals
birds
reptiles
amphibians
fish
What do all vertebrates have?
a backbone
What main features do mammals have?
fur/hair on skin
have a placenta
young feed on milk from mammary glands
external ears (pinna) visible
warm-blooded
What main features do birds have?
skin covered in feathers
have 2 legs and 2 wings instead of forelimbs
lay eggs with hard shell on land
have a beak
warm-blooded
What main features do reptiles have?
dry, fixed scales on skin
lay eggs with rubbery shells on sand
cold-blooded
What main features do amphibians have?
smooth, moist skin
adults usually live on land (so have lungs)
larvae live in water (so have gills)
lay eggs without shells in water
cold-blooded
What main features do fish have?
loose, wet scales on skin
gills to breathe
lay eggs without shells in water
cold-blooded
What characteristic do all arthropods have?
they have jointed legs
What main features do myriapods have?
body consists of many segments
each segment contains at least 1 pair of jointed legs
1 pair of antennae
What main features do insects have?
3 part body (head, thorax and abdomen)
3 pairs of jointed legs
2 pairs of wings
1 pair of antennae
What main features do arachnids have?
2 part body - cephalothorax and abdomen
4 pairs of jointed legs
no antennae
What main features do crustaceans have?
more than 4 pairs of jointed legs
chalky exoskeleton formed from calcium
breathe through gills
2 pairs of antennae
What features do all plants need to have?
At least some parts of any plant are green, caused by the presence of the pigment chlorophyll which absorbs energy from sunlight for the process of photosynthesis
What 2 examples of plants are in the plant kingdom?
Ferns and flowering plants
What features do ferns have?
Have leaves called fronds
- Do not produce flowers but instead reproduce by spores produced on the underside of fronds
What features do flowering plants have?
Reproduce sexually by means of flowers and seeds
Seeds are produced inside the ovary found at the base of the flower
Can be divided into two groups – monocotyledons and dicotyledons
What features do monocotyledons have?
Flowers contain petals in multiples of 3
- parallel leaf veins
What features do dicotyledons have?
Flowers from dicotyledons contain petals in multiples of 4 or 5
Leaves from dicotyledons have reticulated leaf veins (meaning that they are all interconnected and form a web-like network throughout the leaf)
Are viruses part of any classification systems? Why?
Viruses are not part of any classification system as they are not considered living things
How do viruses survive?
They do not carry out the seven life processes for themselves, instead they take over a host cell’s metabolic pathways in order to make multiple copies of themselves
What does a virus contain?
Virus structure is simply genetic material (RNA or DNA) inside a protein coat
There are seven characteristics of living organisms. These characteristics are often described as life processes: Name them.
MRS GREN is the abbreviation for the life processes:
Movement.
Respiration.
Sensitivity.
Growth.
Reproduction.
Excretion.
Nutrition.
Define movement.
An action by an organism or part of an organism causing a change of position or place.
Define sensitivity.
The ability to detect or sense stimuli in the internal or external environment and to make appropriate responses.
Define respiration.
The chemical reactions break down nutrient molecules in living cells to release energy for metabolism.
Define growth.
A permanent increase in size and dry mass by an increase in cell number or cell size or both.
Define reproduction.
The processes that make more of the same kind of organism.
Define excretion.
The removal from organisms of toxic materials, the waste products of metabolism.
For example, animals breathe out carbon dioxide and plants give out oxygen.
Define nutrition.
The taking in of materials for energy, growth, and development.
What do plants require (nutrition-wise)?
Plants require light, carbon dioxide, water, and ions.
What do animals need (nutrition-wise)?
Animals need organic compounds, ions and usually need water.
What controls movement in plants?
In plants, movement happens slowly and on a cellular level.
What controls movement in animals?
In animals, muscles control movement.
What is the word equation for respiration involving oxygen?
Glucose + oxygen → carbon dioxide + water + energy released.
What test can be done to see if a living organism is respiring and what is the result of the test?
The carbon dioxide test can be used to find out if a living organism is present, respiring and producing carbon dioxide.
If so, the lime water will change from colourless to milky.
What is stimulus?
Stimulus is when a living organism is able to detect or sense changes in their environment.
Name five examples of stimuli.
Touch, temperature, chemicals, light and sound.
What is asexual reproduction?
Asexual reproduction involves one parent giving rise to offspring that are often identical to each other and to the parent.
What is sexual reproduction?
Sexual reproduction involves two parent organisms producing gametes which fuse to give rise to the next generation.
Define metabolism.
Metabolism is all the chemical reactions that occur in an organism.
What is the word equation for photosynthesis?
Carbon dioxide + water → light energy and chlorophyll → oxygen + glucose.
There are millions of species of organisms on Earth. Define species.
A species is defined as a group of organisms that can reproduce to produce fertile offspring.
How can species be classified into groups?
These species can be classified into groups by the features that they share.
Linnaeus named organisms in Latin using the binomial system. Define binomial system.
The scientific name of an organism is made up of two parts starting with the genus (always given a capital letter) and followed by the species (starting with a lower case letter).
The sequence of classification is: Name it.
Kingdom, Phylum, Class, Order, Family, Genus, Species.
Studies of DNA sequences of different species show what?
These show that the more similar the base sequences in the DNA of two species, the more closely related those two species are.
The cells of all living organisms contain the following: Name them.
The cells of all living organisms contain the following:
Cytoplasm.
Cell membrane.
DNA as genetic material (either found in the nucleus or free in the cytoplasm).
Ribosomes for protein synthesis.
Enzymes for respiration.
The first division of living things in the classification system is to put them into one of five kingdoms. They are:
Name them.
Animals.
Plants.
Fungi.
Protoctists.
Prokaryotes.
3 Main features of all animals:
They are multicellular.
Their cells contain a nucleus, but no cell walls or chloroplasts.
They feed on organic substances made by other living things.
3 Main features of all plants:
They are multicellular.
Their cells contain a nucleus, chloroplasts and cellulose cell walls.
They all feed by photosynthesis.
3 Main features of all fungi (e.g. moulds, mushrooms, yeast).
Usually multicellular.
Cells have nuclei, cell walls containing chitin, mitochondrion, ribosomes, cell membrane, and cytoplasm.
Do not photosynthesize but feed by saprophytic nutrition.
3 Main features of all Protoctists (e.g. Amoeba, Paramecium, Plasmodium):
Most are unicellular but some are multicellular.
All have a nucleus, some may have cell walls and chloroplasts.
Means some protoctists photosynthesize and some feed on organic substances made by other living things.
2 Main features of all Prokaryotes (bacteria, blue-green algae):
Often unicellular.
- Cells have cell walls (not made of cellulose) and cytoplasm but no nucleus or mitochondria.
Define vertebrate.
An animal that has a backbone extending down the back of the body.
There are 5 classes of vertebrates:
Vertebrates:
Fish.
Mammals.
Amphibians.
Birds.
Reptiles.
Answer the following about Fish:
Body covers.
Limbs.
Breathing.
Reproduction.
Ears.
Teeth.
Body Temp.
Body covers = slimy scales.
Limbs = no limbs but have fins.
Breathing = gills (2 chambered heart).
Reproduction = soft eggs laid in water.
Ears: No ears.
Teeth: One type.
Body Temp: Variable temp.
Name 3 examples of fish.
Bream, bass, eels, tigerfish, sharks, and sea horses.
Answer the following about mammals:
Body covers.
Limbs.
Breathing.
Reproduction.
Ears.
Teeth.
Body Temp.
Body covers = hair or fur.
Limbs = two pairs of legs, fins or wings.
Breathing = lungs.
Reproduction = give birth to live young that suckle milk from the mammary glands.
Ears: External ears.
Teeth: incisors, canines, premolars, molars.
Body Temp: Endothermic.
Name 3 examples of mammals.
Dogs, humans, elephants, and lions.
Answer the following about birds:
Body covers.
Limbs.
Breathing.
Reproduction.
Ears.
Teeth.
Body Temp.
Body covers = feathers.
Limbs = one pair of wings and one pair of legs.
Breathing = lungs.
Reproduction = hard-shelled eggs on land (in nests).
Ears: No external ears.
Teeth: no teeth but has a beak.
Body Temp: Endothermic.
Name 4 examples of birds.
Doves, parrots, ostrich, and penguins.
Answer the following about amphibians:
Body covers.
Limbs.
Breathing.
Reproduction.
Ears.
Teeth.
Body Temp.
Body covers = moist skin.
Limbs = two pairs of legs.
Breathing = larva uses gills in water, adult uses lungs on land and skin in water.
Reproduction = jelly-like eggs laid in water.
Ears: No external ears.
Teeth: One type.
Body Temp: Variable temp.
Name 3 examples of an amphibian.
Frog, toads, salamanders, and newt.
Answer the following about reptiles:
Body covers.
Limbs.
Breathing.
Reproduction.
Ears.
Teeth.
Body Temp.
Body covers = dry scales.
Limbs = two pairs of legs.
Breathing = lungs.
Reproduction = soft-shelled eggs on land.
Ears: No external ears.
Teeth: One type.
Body Temp: Variable temp.
Name 3 examples of a reptile.
Lizards, crocodiles, and snakes.
Define invertebrate.
An animal that lacks a vertebral column or backbone.
All invertebrates with jointed legs, exoskeletons, and jointed bodies are part of the phylum Arthropods.
They are classified further into the following classes:
Crustaceans, myriapods, insects and arachnids.
Answer the following on myriapods:
Number of legs.
Number of wings.
Body divisions.
Number of antennae.
Habitat.
Breath.
Number of legs = 10+ pairs (1 or 2 per segment).
Number of wings = No wings
Body divisions = Segmented body.
Number of antennae = 1 pair.
Habitat = Lives on land.
Breath = Breathes air.
Give two examples of myriapods.
Millipedes and centipedes.
Answer the following on crustaceans:
Number of legs.
Number of wings.
Body divisions.
Number of antennae.
Eyes.
Habitat.
Breath.
Number of legs = 5+ pairs
Number of wings = None.
Body divisions = cephalothorax and abdomen.
Number of antennae = 2 pairs.
Eyes = compound eyes.
Habitat = mainly aquatic.
Breath = Oxygen from water/ air and breathe through gills.
Give three examples of crustaceans.
Crab, lobster, barnacle, shrimp and woodlouse.
Answer the following on insects:
Number of legs.
Number of wings.
Body divisions.
Number of antennae.
Eyes.
Habitat.
Breath.
Cuticle.
Number of legs = 3 pairs.
Number of wings = 2 pairs (may be functionless).
Body divisions = Head, abdomen and thorax.
Number of antennae = 1 pair.
Eyes = compound eyes.
Habitat = mainly terrestrial.
Breath = breathes air through tracheae.
Cuticle = waterproof cuticle.
Give three example of insects.
Flies, cockroaches, beetles and lice.
Answer the following on arachnids:
Number of legs.
Number of wings.
Body divisions.
Number of antennae.
Habitat.
Breath.
Prey.
Number of legs = 4 pairs.
Number of wings = no wings.
Body divisions = cephalothorax and abdomen.
Number of antennae = No antennae.
Habitat = lives on land.
Breath = breathes through book lungs.
Prey = paralyse their prey with poisonous fangs.
Give three examples of arachnids.
Spider, scorpion, tick and mite.
What causes plants to be green and what does it do for the plant?
At least some parts of any plant are green, caused by the presence of the pigment chlorophyll which absorbs energy from sunlight for the process of photosynthesis.
Answer the following about ferns:
Leaves.
Reproduction.
Stems.
Have leaves called fronds.
Do not produce flowers but instead reproduce by spores produced on the underside of fronds.
Underground stems called rhizomes.
Flowering plants (Angiosperm):
Reproduction.
Seeds.
Division into two groups.
Reproduce sexually by means of flowers and seeds
Seeds are produced inside the ovary found at the base of the flower
Can be divided into two groups – monocotyledons and dicotyledons
Flowers:
Monocotyledons.
Dicotyledons.
Flowers from monocotyledons contain petals in multiples of 3.
Flowers from dicotyledons contain petals in multiples of 4 or 5.
Leaves:
Monocotyledons.
Dicotyledons.
Leaves from monocotyledons have parallel leaf veins.
- Leaves from dicotyledons have reticulated leaf veins.
Root system:
Monocotyledons.
Dicotyledons.
Monocotyledons = Fibrous root system which has adventitious roots.
Dicotyledons = Tap root system.
Embryo:
Monocotyledons.
Dicotyledons.
Monocotyledons = Seed contains an embryo with one seed leaf (cotyledon).
Dicotyledons = Seed contains an embryo with two seed-leaves (cotyledons).
Three examples of monocotyledons.
Maize, wheat, grass and rice.
Three examples of dicotyledons.
Bean, cotton, oak tree and roses.
What are viruses (simply)?
Virus structure is simply genetic material (RNA or DNA) inside a protein coat.
Viruses do not carry out the seven life processes for themselves. What do they do instead?
Instead they take over a host cell’s metabolic pathways in order to make multiple copies of themselves.
Viruses are not part of any classification system. Why?
Viruses are not part of any classification system as they are not considered living things.
What are keys used to do?
Keys are used to identify organisms based on a series of questions about their features.
Are organisms with the same genus name are closely related.
Explain your answer.
Yes, organisms placed in the same genus are always more closely related to each other than those in the same species family.
Are organisms with the same genus name are closely related.
Explain your answer.
Yes, organisms placed in the same genus are always more closely related to each other than those in the same species family.
Give two reasons as to why insects are successful on land.
They are covered by a waterproof cuticle that stops them from loosing too much water.
They can fly.
What is the binomial name for humans?
Homo sapiens.
