Biology Multicellular Organisms (2) Flashcards
Continuous variation
Height, weight, hand span
Discrete Variation
Ear lobe shape, gender, tongue roller or not, eye colour
Phenotype
Observational characteristics
Genotype
The individual genes that make up a characteristic
Genetic Counselling
Offered to families with a history of a harmful recessive trait
Carriers
Individuals with a harmful heterozygous genotype but a normal phenotype, so they do not in fact have the harmful condition themselves but they may pass it on
Gene
A section of genetic info that codes for characteristic
Allele
Different forms of the same gene e.g. Blue eyes, brown eyes
P
The parents in a genetic cross
Xylem vessels
Dead cells strengthened by lignin, they transport water for photosynthesis and minerals for growth from the roots to the leaves
Lignin
Supports the xylem and allows it to withstand withstand pressure changes
Phloem vessels
Made of living cells, transport sugars made during photosynthesis from the leaves to the rest of the plant
Made of a sieve tube with companion cells with sieve plates and cytoplasmic strands in the tube
Transpiration
The evaporation of water through the stomata
Transpiration increases when there are
Windy conditions, warm conditions and conditions with high light intensity
Mesophyll cells
Site of photosynthesis
Stomata
Pores which open and close to allow gas exchange
