Y12 Biology term 1

what are xerophytes

• number of fights Miss Hodgson has ever lost

• plants adapted for wet environments

• plants adapted for dry environments

• plants adapted for dark environments

which base is unique to DNA?

• adenine

• thymine

• guanine

• cytosine

which best describes the structure of DNA

• single stranded, anti-parallel

• single stranded, parallel

• double stranded, anti-parallel

• double stranded, parallel

DNA replication is

• conservative

• dispersive

• semi conservative

• labour

phosphodiester bonds are found

• between nucleotides

• between base pairs

• between sugar and base

• between amino acids

Ernie is best described as

• cute

• very cute

• very very cute

• very very very cute

adaptation of lungs for efficient gas exchange

• flattened epithelial cells for short diffusion pathway

• lots of alveoli for large surface area

• good circulation to maintain concentration gradient

• all of these

during forced expiration

• the diaphragm contracts

• the external intercostal muscles contract

• the internal intercostal muscles contract

• nothing contracts

in emphysema ....

• the lungs get cavities

• the lungs get full of tar

• the lungs do not stretch and recoil effectively

• the lungs increase in surface area

what is is mean by countercurrent flow in gills

• Water and blood flow in same direction

• Water and blood flow slowly

• Water and blood flow in opposite directions

• Water and blood flow slowly