Classification of Living Organisms. Flashcards
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.
- Divison 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.
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.
What is a protoctist?
Single-celled plants and animals.
Plants have a transport system called the vascular system with xylem vessels and phloem vessels.
a) What do xylem vessels transport?
b) What do phloem vessels transport?
a) Transport water and mineral salts.
b) Transport sucrose, amino acids and hormones.
Diagrams to study:
Monocotyledon. Dicotyledon. Prokaryotes. Fungi. Viruses. Keys.
