Definitions
No description yet. This curated deck is ready for daily study.
Card preview (24)
define a synapse
as a junction between two neurones or between a neurone and an effector
define a reflex action
as a means of integrating and coordinating stimuli with responses of effectors
define sense organs as
as groups of receptor cells responding to specific stimuli: light, sound, touch, temperature and chemicals
define a drug
as a substance taken into the body that modifies or affects chemical reactions in the body
define a hormone
as a chemical substance, produced by a gland and carried by the blood, which alters the activity of one or more specific target organs
define homeostasis
as the maintenance of a constant internal environment
define mitosis
as nuclear division, giving rise to genetically identical cells (no details of stages required)
define meiosis
as a reduction division in which the chromosome number is halved from diploid to haploid resulting in genetically different cells
define asexual reproduction
as a process resulting in the production of genetically identical offspring from one parent
define sexual reproduction
as a process involving the fusion of the nuclei of two gametes (sex cells) to form a zygote and the production of offspring that are genetically different from each other
define self-pollination
as the transfer of pollen grains from the anther of a flower to the stigma of the same flower or different flower on the same plant
define cross-pollination
as the transfer of pollen grains from the anther of a flower to the stigma of a flower on a different plant of the same species
define sexually transmitted infections
as an infection that is transmitted via body fluids through sexual contact
define growth in terms of
increase in dry mass and size
define development in terms of
increase in complexity
define inheritance
as the transmission of genetic information from generation to generation
define chromosome
as a thread-like structure of DNA, carrying genetic information in the form of the genes
define homologous chromosomes
as chromosomes having the same genes at the same loci but not identical with different alleles.
define the terms haploid nucleus
as a nucleus containing a single set of unpaired chromosomes (e.g. in gametes)
define diploid nucleus
as a nucleus containing two sets of chromosomes (e.g. in body cells)
define gene
as a length of DNA that codes for a protein
define allele
as a version of the same gene
define genotype
genotype as the genetic make-up of an organism in terms of the alleles present
define phenotype
phenotype as the observable features of an organism