Biology Unit 1&2 exam revision

Biotic

A property of the environment relating to living things

Abiotic

A property of the environment relating to non-living things, temprature, water, nutrient availability, acidity.

Tolerance range

-organism have adapted to deal with conditions of their environment

-for each condition there is a range they have adapted to survive in

optimum range- organisms will thrive

zone of physiological stress- survive but experience stress

zone of intolerance- organisms will not survive

Structural adaptations

Evolved modifications to an organism physical structure

Physiological adaptations

Evolved modifications to an organisms internal functioning or metabolic process

behavioural adaptations

evoloved modiciations to an organisms actions

Animals adaptions for hot environments- Thermoregulation

The homestatic process of maintaining a constant internal body temprature

-animals that live in hot enviroments have adapted to minimize there heat loss

Animals adaptions for hot environments- maintaining water balance

In hot and dry enviroments’s animals have generally adapted to increase water input and decrease water output.

Animals adaptions for hot environments- increasing surface area to volume ratio

• decrease the amount of heat that can be released

• decrease amount of heat released

• beneficial for animals that can release warmth into cooler environments ( burrows)

Animals adaptions for hot environments- Increasing water input

Utilising the metabolic production of water produces during aerobic cellular respiration ( glucose+oxygen= carbon dioxide& water)

evading heat

burrowing for cooler temp-hiding in shade

How can animals survive in cold enviroments

Insulation

minimising SA:V ratio

Torpor ( hibernation and brumation)

Vasoconstriction (limiting heat loss at skin surfaces)

Ecosystem

Made up of multiple community interacting with one another and their physical environments’s. Both biotic and abiotic

organisms

living thing made up of one or more cells.

population

a group of organisms of the same species living in the same region

interactions between species- Symbiotic interaction

No species on the earth exist without interaction

the interactions between different species is called symbiotic interactions or symbiosis.

mutualism (+/+)

-Exists between organism from different species that benefit both

Parasitism (+/-)

Describes interaction between 2 or more organisms of different species where one organisms obtains nutrients at the expense of others.

Commensalism

Refers to interactions between 2 organisms of different species where one organism benefits while others experience no benefit or harm

Amensalism

Interaction between 2 or more organisms of different species where one organism experiences a negative effect and other experience a neutral effect.

Competition

Those that occur between 2 organisms competing for the same pool of resources.

what is a keystone species

a species whose effects on the ecosystem are greater than expected relative to its population, the removal of them will have a greater effect on the environment then the removal of other species.

apex predators

are predators, that have no natural predators and are the top of there food chain, they help control the number of many other organisms in the ecosystem

ecosystem engineers

That creates significantly alters or maintains structure of environment

population size

The numbers of people in population that can decrease overtime

carrying capacity

the maximun population size that an environment can sustain indefinetly

population density

the number of individuals in a poluation in a unit area.

mechanical digestion

To be absorbed food must first be broken down in smaller pieces for digestion. physical digestion is where the mechanical movement of the organs and tissues causes breakdown of food into smaller pieces.

chemical digestion

When food undergo chemical digestion Process by which enzymes break down food into small molecules that the body can be absorbed.

Steps of digestion

ingestion, digestion, absorption, elimination

Ingestion

The first stage of food processing in animals: the act of eating.

Egestion

removal of undigested waste

The process of Perastalsis

a series of wave

Digestion

Breakdown of food substances into simpler forms that can be absorbed and used

Absorption

The process by which nutrient molecules pass through the wall of the digestive system into the blood

Elimination

act of removal of materials from the body; in the digestive system, the removal of indigestible materials as feces

Villi

The surface area of the small intestine contains millions folds of villi

Bile

A substance produced by the liver that breaks up fat particles.

Microbiota

They help to digest dietary fiber and polyphenols by a complex metabolic energy

Carnivores

meat eaters

Omnivores

An organism that eats both plants and animals

Herbivores

Consumers that eat only plants

How Herbivores digestive system helps them digest food?

Herbivores have large flat teeth there jaws move side to side to grind the plant matter they consume. They have a lengthy digestive tract that provides enough time for the system and microbes to break down tough plant material

How Carnivores digestive system helps them digest food?

They have sharp teeth which helps rip flesh off prey. There digestive system contains microbiota because meat is dense and relatively easy to digest which allows them to have a short digestive system.

How Omnivores digestive system helps them digest food?

Omnivores have populations of microorganisms living along the digestive tract known as gut microbiota. Omnivores have a stomach with one or more chambers and a specialized digestive tract to process food

What are living things?

animals, plants, fungi, protists, bacteria

8 criteria of living things

movement, respiration, Sensitivity, Growth, Reproduction, Equilibrium, Excretion, Nutrition.

Movement

All living things must be capabale of self

Respiration

All living things can extract energy from Carbohydrates, Fats, and proteins through the biochemical process of aerobic or anaerobic cellular respiration,.

Sensitivity

All organisms respond to stimuli. Plants grow toward a source of light, and the pupils of your eyes dilate when you walk into a dark room.

Growth

All living things can grow and develop over time eg how infants grow into adults.

Reproduction

All living things need to be able to produce a offspring eg cell division and sexual repoduction

Equilbrium

All living things need to be able to maintain stable internal enviroments, this is known as maintaining to homeostasis which allows organiams to be able to tolerate to weather changes.

Excretion

All living things produce waste that must be removed. eg (Urine, Faeces)

Nutrition

All living things extract nutrients from the enviroment which are used to produce cellular energy.

HOw to remeber the 8 criterias of living things

MRS GREEN

Prokaroytes

single celled organism that doesnt contain a nucleus and has free floating dna and rna.

Eukaryotes

multicelled organisms that have a membrane

influence of SA:V on cells

Cells that are small in size are able to easily diffuse water and oxygen and are able to easily diffuse carbon dioxide out the body.

What is a organelle?

A tiny cell structure that carries out a specific function within the cell

membrane bound organelles

Includes endoplasmic reticulum, Golgi apparatus, lysosomes, peroxisomes, mitochondria

non

membrane bound organelles

What is the plasma membrane?

Is a thin boundary of the cell made up of lipids that seperates the intercellular and extracellular enviroments.

Selectively permeable

a property of cell membranes that allows some substances to pass through, while others cannot

Plasma membrane structure

Is a phospholid bilayer embedded with protein, carbohydrates and cholesterol each molecule fulfils a specific function in the membrane

Phospholipids

A molecule that is a constituent of the inner bilayer of biological membranes, having a polar, hydrophilic head and a nonpolar, hydrophobic tail.

Integral proteins are

embedded into the phospholipid bilayer and may either extend all the way or partially through the bilayer.

transmebrane proteins

Integral proteins that span the membrane.

The fluid mosaic model

model that describes the arrangement and movement of the molecules that make up a cell membrane

Osmosis

The process of water moving from an area of high concentration to an area of low concentration

Diffusion

high concetration down a concentration gradient.

active transport

Energy

passive transport

Requires NO energy, Movement of molecules from high to low concentration, Moves with the concentration gradient

hypertonic solution

A solution in which the concentration of solutes is greater than that of the cell that resides in the solution

hypotonic solution

A solution in which the concentration of solutes is less than that of the cell that resides in the solution

isotonic solution

A solution in which the concentration of solutes is essentially equal to that of the cell which resides in the solution

Vacuole

To store waste product

Golgi apparatus

To store and release proteins

Mitochondria

The powerhouse of cell ATP production.

Lysosomes

Protein destruction and digestion of enzymes

Where does protein synthesis occur?

ribosomes

Prokaryotic cell cycle

Growth and development, Maintenance and repair, Reproduction

Step 1 of Prokaryotic cell cycle

Uncoiling of the Prokaryotic circular chromosomes and the replication of DNA

Step 2 of Prokaryotic cell cycle

2 chromosomes attach themselves to opposite sides of the cell

Step 3 of Prokaryotic cell cycle

The formation of a septum

Step 4 of Prokaryotic cell cycle

The formation of a new cell membrane and cell wall and the splitting of cells

What is binary fission?

A form of asexual reproduction in which the parent divides into two approximately equal parts

How to remember Binary fission

DESC

What does D stand for in binary fission

DNA replication

What does E stand for in binary fission

Elongation

What does S stand for in binary fission

Septum formation

What does C stand for in binary fission

Cell division

How long does it take for a cell to divide

A cell has a division time of 20 mins

Eukaryotic Cell Cycle

Interphase (g1, s phase, g2 phase) and then Mitotic phase (mitosis, cytokinesis)

Interphase

period of the cell cycle between cell divisions

G0 phase

A nondividing state occupied by cells that have left the cell cycle, sometimes reversibly.

S stage of interphase

Second stage of INterphase where the DNA is being replicated

G2 phase of interphase

Last phase of interphase in which cell organelles are duplicated in preparation for cell division

cell cycle checkpoints

G1, G2, M

Prophase (mitosis)

First stage of mitosis where the chromatin changes into chromosomes and the spindle fibre forms the nuclear membrane also dissapears

Metaphase (mitosis)

second phase of mitosis, during which the chromosomes line up across the center of the cell