Biology

Credit to Matrix for the image

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An animal cell

Parts of the cell - Mitochondria - energy generation (respiration), ribosomes - protein synthesis, nucleus - contains genetic information and central control of the cell. There's more stuff, and you can learn more about it

Photosynthesis

Biology is life. Every form of life is made out of cells. There are 2 main types of cells: Prokaryotes and Eukaryotes. Prokaryotes are Cells have a very important thing called enzymes. Basically, enzymes break up or put together different chemicals. This is very important: Each type of enzyme can only deal with a specific type of chemical. They also need a specific environment. Homeostatis is the process that cells use to control things, like the pH level in the cell (see Chemistry for pH. Yes, Biology is just Chemistry). To do this, each cell has a semi-permeable membrane. Small things like oxygen and water can just pass through the membrane, but larger things need to be let through a sort of door that allows things in and out. Naturally, things flow from a place of higher concentration to a place of lower concentration. Water can also flow to a place of higher solute concentration. To flow the other way, you need energy. This energy is called ATP.

How do cells get ATP? Well, animals eat food, which gives them sugar, which has glucose, which added to oxygen can be converted into water, carbon dioxide and ATP. Plants, however, have things called Chloroplasts. Inside the Chloroplast, there's Chlorophyll. These reflect green light (so plants are green) and absorb red and blue light. This light is used to break down water and get carbon dioxide that can be converted to glucose.

Evolution:

Charles darwin invented natural selection (but he actually had lots of help from Wallace). The theory is simple. Animals better adapted to new change are going to survive and produce offspring. The variations in animals can happen naturally by accident.

Parts of the nervous sytem, credit to Quizlet

Parts of the body

There's a lot to memorise in the body, but I'll start you off with this:

Nervous system - Split up into two units, the CNS (Central Nervous System) which is the brain and spinal cord and the PNS (Peripheral Nervous System) which is all other nerves. The Nervous system transmits information from the brain to and from other parts of the body. A sensory input is like a touch or something, it's information that is detected by your sensory system. The PNS will then transmit it to the brain, like "There's a spider on me", and the brain (CNS) will make a decision on what to act. The Motor Output is the response that results from when your brain activates other muscles and glands. In the PNS, there's the motor divison which does what we talked about before, and the sensory division that gets sensory info (like before). In the motor division there is somatic and autonomic (Skeletal movement and automated things like lungs and breathing).

Brain - The brain is split up into many parts, such as the cerebral cortex, the cerebellum and the frontal lobe, occipatal lobe, temporal lobe, spinal cord, pons, medula, etc. I will not go into detail with this, but the Cerebral is where most of your conscious thinking happens, while the cerebellum controls more autonomous stuff.

Ecology

A big part of biology, this section is to introduce you to some simple features

Biotic and abiotic- The rock is abiotic. The plant is biotic. Biotic means Living, and Abiotic means not living

Sturt/Strzelecki Desert, Australia. This is an example of a desert biome. Credit shutterstock

A population is a group of the same species in a certain area. A community is a group of populations in a certain area. An ecosystem is a group of biotic and abiotic factors which form a system. A biome is a large area with similar climate/physical features that define it.

Competition can be inter (between different species) or intra (between same species) specific. It is bad for both individuals (--). Symbiosis is a long term relationship between two animals. It includes parasitism, commensalism and mutualism. Parasitism is good for one, bad for the other (+-), commensalism is good for one and neutral for other (+0), while mutualism is good for both (++). Predation is good for predator, bad for prey (+-), which is the same as herbivory (+-)

Behaviour

Habituation - Animals learn to ignore a certain stimulus in the environment

Conditioning - One stimulus triggers animals to do something else. E.g. a dog automatically eats when a bell rings or something.

We've got to my favorite part of biolgy! Animal behaviour. After observing birds in the breeding season for Australia, I have made some discoveries.

Parasitism

Mutualism

We talked about parasitism earlier, so you should know what it is. One day, I saw a Channel-billed Cuckoo out the window, so I followed it. It was being chased by many other birds, such as Little Ravens, Australian Magpies and Noisy Miners. The reason for this is that it is a Brood Parasite, which means that it lays its eggs in other birds nests, so that they will bring up its babies for them. After tracking birds nests for a while, I have now found 5 nests, with the Little Raven nests being most likely for the Cuckoo's baby to be in. Keep checking back for updates, at around the end of this October!

Phototropism, credit to GeeksforGeeks

Plant hormones

We've talked about cells, animals and now we're going to talk about plants! What are plant hormones. Basically, Auxins, Gibberlins and Cytokinins are growth hormones. This means they cause cell division

Auxins cause tropism - directional growth. An example is phototropism: They don't like light, so when light shines on a plant, they move to one side. Now, auxins elongate cells (make them longer), which means that when this happens, one side becomes much longer than the other, sort of pushing the other side over towards the sun.

Gibberlins cause seed germination and overall stem growth, making tall plants (no gibberlins, you get a dwarfed sort of plant)

Ethylene aids in fruit ripening

Abscissic acid causes seed dormancy (keeps seeds not germinating for a while) and creates abscissions (makes dead parts of the plants fall off)

Hormone	Representative Substance	Primary Role(s)
Auxins	Indole-3-acetic acid (IAA)	Promotes cell elongation and primary growth in shoots. Establishes apical dominance (the main stem grows more strongly). Initiates the growth of new roots. Involved in phototropism (growth towards light) and gravitropism (growth in response to gravity).
Cytokinins	Zeatin	Promotes cell division and differentiation, especially in roots and shoots. Delays the aging process (senescence) of leaves. Inhibits apical dominance, promoting the growth of lateral buds. Involved in embryo and leaf development.
Gibberellins (GAs)	Gibberellic acid (GA3)	Promotes stem and shoot elongation. Breaks seed and bud dormancy, promoting germination. Stimulates flowering and fruit development. Contributes to bolting (rapid stem elongation before flowering).
Abscisic Acid (ABA)	Abscisic acid	Induces seed and bud dormancy. Closes stomata in response to water stress to prevent water loss. Counteracts the effects of growth-promoting hormones like gibberellins. Promotes senescence and leaf drop (abscission).
Ethylene	Ethylene (a gas)	Promotes the ripening of fruit. Accelerates the aging and senescence of flowers and leaves. Contributes to the shedding of leaves, flowers, and fruit (abscission). Induces the "triple response" in seedlings to avoid obstacles.

Taxonomy

Living things are classified in many different ways. One way is to group them with Kingdom, Phylum, Order, so on:

Kingdom
Phylum
Class
Order
Family
Genus
Species

You can also use a dichotomous key which at every stage has two options, eventually leading to an answer. The scientific name for scientific naming is Binomial Nomenclature. Each latin name has the genus, then the species, like Ardea Alba, which means Great Egret.

The levels of Classification (Animalia and Plantae)

There are 8 levels of classification however today we will

focus on the 7 main ones. To remember them there is a simple acronym listed

below:

King Philip Came Over From Great Spain

Using the following acronyms, we can convert them to the 7 classifications:

Kingdom Phylum Class Order Family Gensis Species

Now I will explain each classification starting with kingdom.

There are 5 different classifications within the large rangeof kingdom, these 5 classifications are, Animalia, Plantae, Monera, Fungi, Protista.Let’s first talk about the Animalia in the kingdom. In in consists of 5 main classesand 3 subclasses. The 5 main classes are, Reptiles, Amphibians, Mammals, Aves(birds) and Fish. With the 3 sub classes for Mammals being Marsupials, Placentalsand Monotremes, with Marsupials meaning that you give birth to young inside apouch such as kangaroos. Humans are Placentals, being born in the uterus and beingfed milk. The last one is Monotremes which means being born in eggs. Plantae isalso split into 2 categories, a Conifer and a Flowering plant. Howevermore scientifically they are split into 4 categories which are bryophytes(non-vascular plants like mosses), pteridophytes (seedless vascular plants likeferns), gymnosperms (cone-bearing seed plants), and angiosperms (flowering plants). Bryophytes are non-vascular plants meaning they don’t have the tissuesthat support them transferring water and nutrients throughout their body. Anexample of Bryophytes are mosses, liverworts and hornworts. Pteridophytesare seedless vascular plants that have most tissues, they reproduce mainlyusing spores rather than seeds. An example of a Pteridophytes is ferns andhorsetails. A gymnosperm is a cone bearing seed plant that produces seedsrather than flowers, the term gymnosperm literally translates to “naked plant.”A example of gymnosperm are Cycads, Pines and Conifers. The last one is angiosperms,which are a type of flowering plant with the most diverse group, they produceseeds enclosed with a fruit. And example of a angiosperms are rice, corn banana and mangos.