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biology - Coggle Diagram
biology
life
cell structure, reproduction (asexual, multicellular), metabolism, response, homeostasis, inheritance 🡪 DNA, evolution, similar chemical basis
radiation from the sun: all energy comes from sun --> photosynthesis
chemical basis of life: carbon C 🡪 organic chemistry, hydrogen H, oxygen O, nitrogen N ... 🡪 25 elements important for life
(chemical) element: pure substance, organism: living thing, cohesion: water molecules stick to one another, adhesion: attraction with unlike molecules, pH scale: how acidic or basic a solution is
reproduction
all organisms will die
in order to survive in a species level, they need to reproduce
pass on their genes to next generations
two basic methods for reproduction: asexual (no gametes) and sexual (with gametes)
asexual reproduction
simple, easy, low cost and fast
offspring will have exact same genes as their parents 🡪 cloning
less variation between individuals (only those caused by mutation and environmental factors) 🡪 slower evolution
forms: binary fission (bacteria, archaea), multiple fission (protists like malaria), budding (yeast), vegetative propagation (plants), spore formation (fungi, algae some, plants)
sexual reproduction
difficult, expensive and time consuming
gametes are needed 🡪 sperm cell / pollen grain, ovum a.k.a. egg cell
gametes are formed in special cell division = meiosis
the number of chromosomes is reduced by half
random recombination of chromosomes
each gamete will have unique genetic composition
from one germ cell will become 4 gametes
fusion of gametes = fertilization
number of chromosomes is doubled back to original number
new properties will emerge
lot of variation between individuals 🡪 faster evolution
animal fertilization
internal (mammals, birds, reptiles and many invertebrates)
gametes fuse inside the female body
external (amphibians, fish)
gametes fuse outside
most animals are unisexual 🡪 organism can produce only male or female gametes
many invertebrates are hermaphrodite 🡪 organism can produce both gametes
evolution timeline
all organisms have similar basic structure (chemical structure, DNA)...) 🡪 same origin
biodiversity = variability of life on earth
ecological diversity (ecosystem diversity)
taxonomic diversity (species diversity)
genetic diversity (within species)
taxonomy = classifying organisms