Edexcel: Combined Biology (Paper 1)

Eukaryotic cells

Contain a nucleus and other organelles that are bound by membranes.

prokaryotic cell

cell lacking a nucleus and most other organelles

Nucleus

A part of the cell containing DNA and RNA and responsible for growth and reproduction

Cytoplasm

A jellylike fluid inside the cell in which the organelles are suspended

cell membrane

A cell structure that controls which substances can enter or leave the cell.

Mitochondria

An organelle found in large numbers in most cells, in which the biochemical processes of respiration and energy production occur.

Ribosomes

site of protein synthesis

cell wall

A rigid structure that surrounds the cell membrane and provides support to the cell. made of cellulose

Vacuole

Cell organelle that stores materials such as water, salts, proteins, and carbohydrates

Chloroplast

An organelle found in plant and algae cells where photosynthesis occurs

Plasmid DNA

A ring of DNA capable of replicating itself. Found in bacteria commonly.

Multicellular organisms

Organisms composed of many cells (Ex. tissue, humans, etc.)

sexual reproduction

A reproductive process that involves two parents that combine their genetic material to produce a new organism, which differs from both parents

egg cell

female reproductive cell

sperm cell

male reproductive cell

electron

microscope that can magnify objects 100s of 1000s of times

Magnification

the ratio of an object's image size to its real size

Enzymes

Catalysts for chemical reactions in living things

active site

The part of an enzyme where the chemical reaction occurs.

factors which affect the rate of reaction

-temperature

-pH

-substrate concentration

Denature

A change in the shape of an enzyme that can be caused by changes in temperature or pH

Pepsin

Enzyme that breaks down proteins

Amylase

enzyme that breaks down starch

lock and key

The idea that enzymes are specifically shaped to fit only one type of substrate

Carbohydrase

enzyme that breaks down starches into sugars

Protease

enzymes that digests protein

Lipase

enzyme that breaks down fat

Benedict's

detects the presence of sugars.

Starch test

Iodine is used. If it's present, the sample goes from brown/orange to blue/black

Lipids test

Emulsion test. combine substance with ethanol and pour into water. if it's present they will show as milky

Proteins test

Biuret test. If present, the solution will turn purple

Diffusion

Movement of molecules from an area of higher concentration to an area of lower concentration.

Osmosis

the net movement of water molecules across a partially permeable membrane from an area of high water concentration to an area of lower water concentration.

Partially permeable membrane

a membrane that allows only certain substances to pass through

active transport

the movement of ions or molecules across a cell membrane into a region of higher concentration, requiring energy.

Mitosis

cell division in which the nucleus divides into nuclei containing the same number of chromosomes

Diploid

2 sets of chromosomes

Haploid

having a single set of unpaired chromosomes

cell differentiation

the process by which a cell becomes specialised for a specific structure or function.

Cancer

disorder in which some of the body's cells lose the ability to control growth

stem cells

unspecialised cells that retain the ability to become a wide variety of specialised cells

Stem cell uses

Therapeutic cloning- skin, treatment of cancers, and generation of tissues

Meristem

Plant tissue that remains embryonic as long as the plant lives, allowing for indeterminate growth.

CNS (central nervous system)

brain and spinal cord

nervous pathway

stimulus → receptor → sensory neurone → CNS → Motor neurone → effector → response

sensory neurones

neurones that carry incoming information from the sensory receptors to the brain and spinal cord

motor neurones

The neurones that carry electrical impulses from the CNS to effectors

relay neurones

Neurones that carry information from a sensory nerve cell to a motor nerve cell

Synapses

connections between neurones

Reflexes

specific patterns of motor response that are triggered by specific patterns of sensory stimulation

Meiosis

Cell division that produces reproductive cells in sexually reproducing organisms

Gametes

sex cells

asexual reproduction

A reproductive process that involves only one parent and produces offspring that are identical to the parent.

DNA

A complex molecule containing the genetic information that makes up the chromosomes.

DNA bases

Adenine, Thymine, Cytosine, Guanine (A-T, C-G)

chromosomes

threadlike structures made of DNA molecules that contain the genes

Gene

A segment of DNA on a chromosome that codes for a specific trait

Genome

All the genetic information in an organism; all of an organism's chromosomes.

Mutation

a random error in gene replication that leads to a change

double helix

two strands of nucleotides wound about each other; structure of DNA

Allele

Different forms of a gene

Dominant

An allele that is always expressed

Recessive

An allele that is masked when a dominant allele is present

Homozygous

An organism that has two identical alleles for a trait

Heterozygous

An organism that has two different alleles for a trait

Genotype

genetic makeup of an organism

Phenotype

An organism's physical appearance, or visible traits.

Zygote

fertilised egg

environmental variation

Variation among individuals that is due to differences in the environment.

natural selection

A process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.

antibiotic resistance

Resistance evolving rapidly in many species of prokaryotes due to overuse of antibiotics, especially in agriculture.

Fossils

Preserved remains of once-living organisms

Classification

The process of grouping things based on their similarities

kingdom, phylum, class, order, family, genus, species

kenny puts condoms on for good sex

Protists

A eukaryotic organism that cannot be classified as an animal, plant, or fungus.

selective breeding

The process of selecting a few organisms with desired traits to serve as parents of the next generation

communicable disease

a disease that is spread from one host to another

non-communicable disease

a disease not capable of being spread from one person to another

malaria

Protist which causes damage to red blood cells and can damage the liver. Spread via Mosquitoes

HIV

the virus that causes AIDS which destroys red blood cells

Chlamydia

A bacterial infection that affects the reproductive organs of both males and females

Antigen

A protein that, when introduced in the blood, triggers the production of an antibody

Antibodies

Proteins that attach to antigens, keeping them from harming the body

immunisation

Giving a vaccine that allows immunity to develop without exposure to the disease itself.

antibiotics

Drugs that block the growth and reproduction of bacteria

Preclinical testing

Drug tests carried out in a laboratory on cells, tissues and live animals.

clinical testing

another name for clinical trials

Risk factors of non communicable diseases

-smoking

-malnutrition

-alcohol

-lack of exercise

-obesity

cardiovascular disease

A general term for all diseases of the heart and blood vessels.

Stents

wire mesh cylinder inserted into a clogged artery to hold it open

Evolution

The gradual change in a species over time