Definitions

Question 1

Diffusion

Answer 1

Diffusion is the passive movement of particles from a region of high concentration to a region of low concentration.

Question 2

Osmosis

Answer 2

Osmosis is the passive movement of water molecules, across a partially permeable membrane, from a region of lower solute concentration to a region of higher solute concentration.

Question 3

Enzyme

Answer 3

Enzyme: globular proteins that act as catalysts for biochemical reactions.

Question 4

Active Site

Answer 4

Active site: specific region on the surface of an enzyme to which substrates bind and which catalyzes biochemical reactions.

Question 5

Denaturation

Answer 5

Denaturation is a structural change in a protein that results in the loss (usually permanent) of its biological properties. Refer only to heat and pH as agents.

Question 6

Cell Respiration

Answer 6

Cell respiration is the controlled release of energy from organic compounds in cells to form ATP.

Question 7

Gene

Answer 7

Gene: a heritable factor that controls a specific characteristic.

Question 8

Allele

Answer 8

Allele: one specific form of a gene, differing from other alleles by one or a few bases only and occupying the same gene locus as other alleles of the gene.

Question 9

Genome

Answer 9

Genome: the whole of the genetic information of an organism.

Question 10

Gene Mutation

Answer 10

A change in the base-sequence of an allele.

Question 11

Homologous Chromosomes

Answer 11

Chromosome pairs, one from each parent, that are identical or very similar in gene composition. Can be identified by size, banding pattern and centromere position.

Question 12

Genotype

Answer 12

Genotype: the alleles of an organism.

Question 13

Phenotype

Answer 13

Phenotype: the characteristics of an organism.

Question 14

Dominant Allele

Answer 14

Dominant allele: an allele that has the same effect on the phenotype whether it is present in the homozygous or heterozygous state

Question 15

Recessive Allele

Answer 15

Recessive allele: an allele that only has an effect on the phenotype when present in the homozygous state.

Question 16

Codominant Alleles

Answer 16

Codominant alleles: pairs of alleles that both affect the phenotype when present in a heterozygote.

Question 17

Homozygous

Answer 17

Homozygous: having two identical alleles of a gene.

Question 18

Heterozygous

Answer 18

Heterozygous: having two different alleles of a gene.

Question 19

Locus

Answer 19

Locus: the particular position on homologous chromosomes of a gene.

Question 20

Carrier

Answer 20

Carrier: an individual that has one copy of a recessive allele that causes a genetic disease in individuals that are homozygous for this allele.

Question 21

Test Cross

Answer 21

Test cross: testing a suspected heterozygote by crossing it with a known homozygous recessive.

Question 22

Sex Linkage

Answer 22

An association between genes in sex chromosomes that makes some traits more prevalent in on gender than the other. These genes are located on the non-homologous region of the X-chromosome in humans.

Question 23

Clone

Answer 23

Clone: a group of genetically identical organisms or a group of cells derived from a single parent cell.

Question 24

Species

Answer 24

Species: a group of organisms that can interbreed and produce fertile offspring.

Question 25

Habitat

Answer 25

Habitat: the environment in which a species normally lives or the location of a living organism.

Question 26

Population

Answer 26

Population: a group of organisms of the same species who live in the same area at the same time.

Question 27

Community

Answer 27

Community: a group of populations living and interacting with each other in an area.

Question 28

Ecosystem

Answer 28

Ecosystem: a community and its abiotic environment.

Question 29

Ecology

Answer 29

Ecology: the study of relationships between living organisms and between organisms and their environment.

Question 30

Trophic Level

Answer 30

A class of organisms that share the same position in a food chain (such as producers, primary consumers etc)

Question 31

Evolution

Answer 31

Evolution is the cumulative change in the heritable characteristics of a population.

Question 32

Pathogen

Answer 32

Pathogen: an organism or virus that causes a disease.

Question 33

Resting Potential

Answer 33

Resting potential: the electrical potential across the plasma membrane of a cell that is not conducting an impulse.

Question 34

Action Potential

Answer 34

Action potential: the reversal and restoration of the electrical potential across the plasma membrane of a cell, as an electrical impulse passes along it (depolarization and repolarization).

Question 35

Nutrient

Answer 35

Nutrient: a chemical substance found in foods that is used in the human body.

Question 36

Stimulus

Answer 36

A stimulus is a change in the environment (internal or external) that is detected by a receptor and elicits a response.

Question 37

Response

Answer 37

A response to a change in (internal or external) environment, detected by a receptror.

Question 38

Reflex

Answer 38

A reflex is a rapid, unconscious response.