biology

independent variable

the one that changes

dependant variable

the one that is measured

control variable

the one that stays the same

sensitivity

respond to the surroundings

respiration

release of energy cells

excretion

removal of metabolic waste

reproduction

production of new organisms

growth

increase in number of cells

nutrition

taking in food

prokaryotic

Type of cell lacking a nucleus and other membrane-bound organelles. Examples include bacteria and archaea.

eukaryotic

A type of cell that has a nucleus and other membrane-bound organelles.

similarities between prokaryotic and eukaryotic

Both prokaryotic and eukaryotic cells are basic units of life, contain genetic material in the form of DNA, and are capable of carrying out essential cellular processes such as metabolism and reproduction.

difference between prokaryotic and eukaryotic organisms

Prokaryotic organisms lack a nucleus and other membrane-bound organelles. They are generally smaller and simpler in structure compared to eukaryotic organisms, which have a nucleus and other membrane-bound organelles.

nucleus

The center of a cell that contains genetic material and controls cell functions.

mitochondria

Organelle that produces energy in eukaryotic cells through cellular respiration.

ribososmes

Photosynthesis:

Process by which plants convert light energy into chemical energy in the form of glucose, using carbon dioxide and water.

cell membrane

This structure surrounds and protects the cell, controlling the movement of substances in and out.

lysosomes

Organelles that contain digestive enzymes to break down waste materials and cellular debris. They are involved in the maintenance of cellular homeostasis and the recycling of cellular components.

cytoplasm

The jelly-like substance that fills a cell and surrounds its organelles, where many cellular processes take place.

vacuole

Organelle found in plant and animal cells that stores water, nutrients, and waste products. It helps maintain turgor pressure and regulates pH levels.

cell wall

Structure that surrounds the cell membrane in plant, fungi, and bacterial cells. Its main function is to provide support and protection to the cell.

chloroplasts

Organelles found in plant cells that contain chlorophyll, which is used in photosynthesis to convert light energy into chemical energy in the form of glucose.

the importance of cell differentiation in the development of specialised cells

…………. is crucial in the development of specialised cells as it allows cells with identical genetic information to acquire distinct structures and functions. This process enables cells to specialise for specific tasks, contributing to the formation of tissues, organs, and ultimately the complex functioning of multicellular organisms.

pathogens

……… are microorganisms or agents that can cause disease in living organisms, including humans, animals, and plants. They include various types of bacteria, viruses, fungi, protozoa, and parasites. Pathogens are capable of invading the host's tissues and disrupting normal bodily functions, leading to infections and illnesses.

examples of pathogens

~Bacteria (ex: e.coli) eukaryotic

~Viruses (ex: AIDS) neither

~ Fungi (ex: mucor) eukaryotic

~ Protozoa (ex: malaria) unicellular eukaryotes

~Parasites (ex. tapeworms) eukaryotic

~Protoctists (ex. algae) eukaryotic

are bacteria eukaryotic or prokaryotic

they are prokaryotic

are fungi eukaryotic or prokaryotic

are eukaryotic

are parasites eukaryotic or prokaryotic

they are eukaryotic

are viruses eukaryotic or prokaryotic

they are neither prokaryotic or eukaryotic

are protozoa eukaryotic or prokaryotic

they are unicellular eukaryotic

are protoctists eukaryotic or prokaryotic

eukaryotic

how does a virus differ from a bacterium

…….. need a host to survive

viruses are generally smaller than ……..

……. bacteria is a living organism, while …… can replicate only within the host cell

fungi are/have

some are multicellular

all have a nucleus

none contain chloroplasts

all have cell walls

bacteria are/have

none are multicellular

none have a nucleus

some have chloroplasts

all have cell walls

protoctists are/have

none are multicellular

all have a nucleus

some contain chloroplasts

some have cell walls

levels of organisation

…………… in organisms include organelles cells, tissues , organs, and systems. These levels build upon each other, with each level performing specific functions that contribute to the overall functioning of the organism.

example of an organelle

ex: mitochondria

example of a cell

muscle cells

example of an organ

heart

example of a system

cardiovascular system

diffusion

…. is the passive process by which molecules or particles move from an area of higher concentration to an area of lower concentration. It occurs due to random molecular motion and seeks to equalise the concentration gradient, leading to a net movement of substances down their concentration gradient.

osmosis

the net movement of water from an area of high water potential to an area of lower water potential through a partially permeable membrane until dynamic equilibrium is reached

active transport

a process that involves the movement of molecules from a region of lower concentration to a region of higher concentration against a gradient or an obstacle with the use of external energy

rate of movement

The ….…….. refers to the speed or velocity at which a substance or particle moves within a given time frame. It can be influenced by factors such as temperature, concentration gradient, molecular size, and the presence of barriers or transport mechanisms.

surface area affects rate of movement

…….….. affects the rate of movement by increasing the available space for molecules to interact or diffuse. A larger ………. allows for more efficient exchange of substances, as there is a greater ……….. for molecules to pass through or come into contact with, resulting in faster rates of movement.

distance affects the rate of movement

…….. affects the …….. as an increase in distance generally leads to a slower rate. The larger the ……., the longer it takes for molecules or particles to travel, resulting in a slower rate of movement. Shorter distances allow for faster and more efficient movement between locations.

temperature affects the rate of movement

……….. affects the rate of movement by increasing the kinetic energy of molecules. Higher temperatures result in faster molecular motion, leading to increased collisions and more rapid diffusion or movement of substances. Lower temperatures decrease molecular motion and thus slow down the rate of movement.

the concentration gradient affects the rate of movement

The ………….……. affects the rate of movement by driving the flow of substances from an area of higher concentration to an area of lower concentration. A steeper concentration gradient results in a faster rate of movement, while a smaller gradient leads to a slower rate of movement.

DNA

Each molecule of ….….. is a double helix formed from two complementary strands of nucleotides held together by hydrogen bonds between G-C and A-T base pairs

adenine goes with

thymine goes with

guanine goes with

cytosine goes with

what does the nucleus of a cell contain

chromosomes, in which genes are located

allele

An …… is an alternative form of a gene, occurring at a specific locus on a chromosome, that contributes to variations in traits among individuals of a population.

dominant

In DNA, the term "…….." refers to an allele that expresses its trait even when present in only one copy, overshadowing the expression of a recessive allele.

recessive

In DNA, …….. refers to an allele that is masked or not expressed when a dominant allele is present. ……… alleles typically require two copies to be expressed phenotypically.

homozygous

a condition in which an individual possesses two identical alleles for a specific gene, one inherited from each parent, resulting in a uniform genetic trait expression.

heterozygous

an individual having two different alleles for a particular gene. In DNA, it means that the two copies of the gene possess different genetic information at that specific locus.

Phenotype

The observable characteristics in an individual resulting from the expression of genes. visible

Genotype

the collection of alleles that determine an organism's characteristics. non visible

patterns of monohybrid inheritance using a genetic diagram (punnett squares)

Monohybrid inheritance involves the inheritance of a single gene. A Punnett square, a genetic diagram, is used to predict the possible genotypes and phenotypes of offspring based on the genotypes of the parents.

the dominant allele (BB) “dominates” over the recessive allele. the recessive allele (bb) is “submissive” to the dominant allele

b + b = bb

B + b = Bb

b + B = Bb

B + B = BB

mutation

A change in the DNA base sequence, known as …….. , can lead to altered amino acids in a protein. This can affect the protein's structure and function, potentially changing the organism's characteristics. These changes can range from subtle modifications to significant disruptions in biological processes, leading to various phenotypic outcomes. If inherited, can lead to variations in traits and genetic disorders.

carbohydrates

……… contain the elements carbon, hydrogen and oxygen. plant cell walls are made of the ………., cellulose. plants store ……… as starch. the starch in plant cells is insoluble, it has no osmotic effect on the cell.

the storage carbohydrate animal is

glycogen, which is found mainly in the muscles and the liver.

proteins

…….... contain the elements of carbon, hydrogen, oxygen, and nitrogen . ………. are formed from amino acids, which are linked together by peptide bonds to create complex, three-dimensional structures.

lipids

……. contain carbon, hydrogen, and oxygen. Some ……. may also contain phosphorus (P) and other elements. ……. are diverse molecules that include fats and oils, composed of fatty acids and glycerol.

enzyme

they are proteins that help speed up metabolism, or the chemical reaction in our bodies. They build up some substances, and break others down.

Enzymes and biological catalysts in metabolic reactions

Enzymes act as biological catalysts in metabolic reactions, facilitating chemical reactions by lowering the activation energy required for them to occur. They speed up the rate of reactions, enabling efficient metabolism by selectively binding to substrates and converting them into products without being consumed in the process.

Digestive enzymes

……………. play a vital role in breaking down complex food molecules for absorption. Amylase and maltase act on starch, breaking it down into glucose for energy. Proteases break down proteins into amino acids, which are essential for building new proteins and other cellular processes in the body.

denatured enzyme

………………. occurs when the protein structure of the enzyme is disrupted, usually by factors such as high temperatures or extreme pH levels. This disrupts the enzyme's active site, rendering it unable to bind to its substrate and catalyse the intended chemical reaction.

how changes in temperature affect the activity of an enzyme

As the temperature increases so does the rate of enzyme activity. If the temperature decreases there is less kinetic energy, so fewer collisions mean a decrease in enzyme activity. if the temperature is too high or too low

pH

the value at which an enzyme works best

high and low pH…

… denatures enzymes

amylase, salivary gland

break down starch

protease, stomach

break down proteins

restriction, bacteria

cutting DNA at certain points

ligase , cell nucleus

joining DNA / genes

the independent variable goes on the

x axis

the dependent variable goes on the

y axis

concentration gradient

occurs when the concentration of particles is higher in one area than another. In passive transport, particles will diffuse down a concentration gradient, from areas of higher concentration to areas of lower concentration, until they are evenly spaced.

starch

is a carbohydate