Key Terms Flashcards
(27 cards)
Define tropism
It is a plant growth response to stimuli controlled by hormones called auxin
What is the purpose of a kidney
They are involved in filtering blood, removing unwonted substances and balancing needed substances
Define excretion
The process by which waste products of the metabolism are removed from the body
Define fertilisation
Involves the fusion of a male and female gametes to produce a zygote
Define asexual reproduction
It is not necessary to have two parents, the offspring is genetically identical to the parent, quicker
Define cross pollination
The transfer of pollen from the anther of one plant to the stigma of another
Define germination
Process by which new plants grow from seeds
How many chromosomes in gametes and zygotes
Gametes- 23 (haploid cell)
Zygotes- 46 (diploid cell)
Define transpiration
Loss of water by evaporation from the leaf through the stomata
What is a xerophyte
They are plants that preserve water E.G. cactus
The colours of bicarbonate indicator
Purple - no CO2
Red - Little CO2
Yellow - lots of CO2
Define homoeostasis
The process of maintaining a constant internal environment
What are hormones
They are chemical messengers that travel in the blood
Define population
Group of individuals all of one species in a location
Define community
All the organisms within an ecosystem
Define habitat
Where individual species live with specific physical characteristics
Define ecosystem
The interactions of all the organisms living within an area and the environment around them
Define gene
A section of DNA which codes for a specific protein
Define homozygous
Two alleles for a characteristic are the same
Define dominant
Only one copy of this allele is needed to be expressed in the phenotype
Define heterozygous
Two alleles for a characteristic are different
Define Co - dominant
When two different alleles are both expressed in the phenotype
Define recessive
Two copies of this allele are needed to be expressed in the phenotype
What is an allele
A specific version of a gene
