CSEC Biology: Essential Lecture Notes

Flashcards covering key vocabulary from CSEC Biology lecture notes.

Cells

All living things are made up of these.

Unicellular

Organisms made of only one cell.

Multicellular

Organisms that require a more complex structure, and specialized systems may be necessary to enable the organism to digest and transport food, escape predators, seek shelter and find a sexual mate to continue the species.

Growth

Permanent increase in size by increasing dry mass and number of cells.

Respiration

Release of energy through a molecule known as ATP for metabolism.

Irritability

Detection and response to a change in the environment, such as temperature.

Movement

An action by an organism, causing a change in position or place.

Nutrition

Taking in, utilization and storage nutrients from different sources.

Excretion

Removal of metabolic waste, toxic products and excess in the body.

Reproduction

Production of new individuals to continue the species.

Locomotion

When an organism is able to move from one location to another.

Artificial classification

Involves categorising by certain features of anatomy.

Natural Classification

Based on an organism’s DNA base sequences and evolutionary descent and is structured as a hierarchy, with each level being called a taxon.

Taxon

Each level of the natural classification hierarchy

Binomial name

A system of classifying organisms with two names: a GENUS and a SPECIES.

Taxonomy

Each organism belongs to one of FIVE KINGDOMS, placing each organism in a category.

Ecosystem

A system of living and non-living factors that interact with each other.

Biotic

All organisms that either produce their own food or consume other organisms for food.

Abiotic

The physical features of the environment, which will affect the types of numbers of the species populations living in the ecosystem.

Population

A group of one species within a particular habitat.

Community

All the populations of different species in a particular habitat.

Niche

An organism’s role in its environment.

Habitat

The place where an organism lives.

Food Chain

The feeding sequence of organisms to transfer energy.

Autotrophs

Organisms that produce food by photosynthesis.

Heterotrophs

Organisms that eat other organisms to gain their food.

Decomposers

Organisms that obtain nutrition by breaking down the dead remains of other organisms and absorbing nutrients, releasing CO2 as a result.

Trophic Level

Each stage in the food chain.

Edaphic

A soil habitat.

Humus

The top layer of most soils, comprised of the natural decay of materials such as leaves and animal matter that have accumulated. It is the most fertile layer.

Loam

A fertile mixture of humus, sand and clay.

Food Web

A combination of several food chains within a habitat or ecosystem.

Predator

When one animal hunts and eats another animal, the hunter.

Prey

When one animal hunts and eats another animal, the hunted.

Symbiosis

Relationships where at least one organism benefits.

Parasitism

One organism is harmed while the other benefits.

Commensalism

One organism benefits and the other is neither harmed nor benefits.

Mutualism

Both organisms benefit from the relationship.

Natural Selection

A process that favours species that are best adapted to their environments.

Speciation

The rise of a new and distinct species.

Transect

A straight path is chosen and the quadrat is laid out in intervals along that track, with the species being counted each time.

Random Sampling

The quadrat is tossed from a certain point in various directions. Eyes are closed to prevent bias.

Overcompetition

Population may be too large and unvaried and resources such as food, water and shelter are limited.

Invasive Species

A new predator migrated into the habitat and reduces the population of many organisms.

Ecological Disruption

Natural disasters or human intervention and activity can disrupt the natural habitats of organisms, displacing them.

Renewable Resources

Can be reused or replenished in a relatively short time.

Non-Renewable Resources

Are in finite supply and cannot be replenished in a short time.

Biodegradable Waste

Meaning they can be broken down quickly by microorganisms.

Non-Biodegradable Waste

Meaning they take a very long time to be broken down.

Photosynthesis

Plants undergo this process and remove CO2 from atmosphere.

Smog

Combination of sulphur dioxide and nitrogen oxide which forms a layer of thick haze. This can cause respiratory diseases.

Eutrophication

When the nitrates and phosphates in pesticides leak into water ecosystems, they can speed up the growth of underwater plants such as algae.

Leaching

Where the chemicals dissolve into the soil and depletes its usable nutrients, making it unsuitable for plant growth.

Conservation

The preservation of the Earth’s natural resources so that they are available for future generations.

Light-Dependent Stage

Light energy is captured by chlorophyll in the chloroplast and then converted into a usable energy called ATP.

Light-Independent Stage

The hydrogen produced in photolysis is used to reduce carbon dioxide to glucose. The ATP required for this process comes from the light-dependent stage.

Glucose

The simplest carbohydrate; used for respiration.

uses of Glucose

Needed for the release of energy and to form starch and proteins for storage. Used to produce cellulose for cell walls, and to form fruits and food stores in seeds.

Photosynthesis

The process whereby light energy is absorbed by chlorophyll and transformed into chemical energy used in the synthesis of carbohydrates from water and carbon dioxide. Oxygen is released during the process.

Upper Epidermis

Part of leaf with a waxy cuticle above it to prevent water loss. Is transparent to let sunlight into leaf; contains few to no stomata.

Palisade Mesophyll

Part of leaf densely packed with chloroplasts; main site of photosynthesis

Spongy Mesophyll

Part of leaf with many loose air spaces to allow flow of gases and water; contains few chloroplasts.

Lower Epidermis

Part of leaf with guard cells that open and close stomata to allow gaseous exchange of oxygen and carbon dioxide.

Starch Grains

Plant cells store glucose as __ in their cells while animals store it as glycogen granules.

Diffusion

The movement of molecules from a high to low concentration until equilibrium.

Active Transport

The movement of molecules from low to high concentration, using ATP.

Osmosis

The movement of water molecules from a high to low concentration across a partially permeable membrane.

Plasmolysed

A plant cell placed in a concentrated solution; cell membrane and cytoplasm retracts from cell wall, and vacuole shrinks as water is lost.

Crenated

Animal red blood cells placed in a concentrated solution shrivel and are said to be this.

Enzymes

Are used in ALL chemical reactions in living things; this includes respiration, photosynthesis, movement, growth, excretion of toxins in the liver and more.

Substrates

The molecules that enzymes act upon; turns into products.

Denatured

When heat breaks down the structure of the enzyme, making the substrate no longer fits because the active site changes.

Balanced Diet

A diet that contains all the required nutrients in the correct proportions.

Malnutrition

Nutrients are lacking or in excess, this is.

Carbohydrates

Provides energy for respiration and is stored as STARCH in plants and GLYCOGEN in animals.

Proteins

Made of nitrogen, oxygen, carbon, etc. broken down into amino acids.

Lipids

Helps store energy for warmth and insulation.

Water

Acts as a solvent to absorb, dissolve and transport materials in the body; produces sweat to regulate body temperature and urine to excrete urea and excess water.

Pancreas

Releases many enzymes and juices that neutralize stomach acid; occurs in the duodenum

Villi Lining

A very thin layer of epithelial cells under microvilli to allow easy diffusion.

Oesophagus

Peristalsis allows muscles to push food down to this organ.

Stomach

Protein is chemically digested into chyme, and HCl kills bacteria.

Bile

Enzyme secreted, which emulsifies fats, making them easier to digest; stored in the gallbladder.

Ileum

Villi in this organ allows the absorption of food into the blood.

Large Intestine/Colon

The extraction of water in the colon and feces are stored in the rectum.

Anus

The releasing of feces from the rectum.

Incisors

Used for cutting food.

Canines

Used for tearing meat.

Premolar and Molars

Used for grinding food into smaller pieces.

Structure for the Human Tooth

Consists of the Enamel, Dentine, Pulp Cavity, and Cement.

Fibre

Is found in foods such as vegetables, fruits and whole wheat, is mostly insoluble and cannot be fully broken down by the human digestive system.

Assimilation

After the digested nutrients have been absorbed into the bloodstream from the villi in the small intestine, they are then transported to cells in various parts of the body by the blood, so they can be utilized.

Hepatic Portal Vein

Transports nutrient-rich blood from the alimentary canal to the liver.

Hepatic Vein

Transports blood from the liver to the heart.

Breathing

The mechanism that moves air in and out of our lungs.

Gaseous Exchange

The process in which some of the oxygen in the air in our lungs diffuses into the blood whilst some of the carbon dioxide in our blood diffuses into the air.

Respiration

The release of energy due to the oxidation of glucose, if oxygen is available.

Oxygen

The lungs move by diffusion into the red blood cells in the blood and some of the carbon dioxide in the blood cells diffuses into the lungs to be exhaled.

Alveoli

Have adaptations for carrying out their function of gaseous exchange: LARGE SURFACE AREA, THIN WALLS, MOISTURE ,MANY CAPILLARIES.

Lactic acid

Is the breaking down of this and can lead to a burning sensation as well as fatigue and muscle cramps.