Question 18M.2.HL.TZ1.2
| Date | May 2018 | Marks available | [Maximum mark: 4] | Reference code | 18M.2.HL.TZ1.2 |
| Level | HL | Paper | 2 | Time zone | TZ1 |
| Command term | Outline, State | Question number | 2 | Adapted from | N/A |
State two features that are found only in mammals.
[2]
a. hair/fur
b. mammary glands/breasts/(secretion of) milk/lactation
c. sweat glands
d. lungs with alveoli
e. placenta (in most mammals)
f. fetus develops in uterus/gives birth to live young
Do not award marks for any answers after the first two given.
Birds, bats and humans are all vertebrates with pentadactyl limbs. Birds and bats use their forelimbs to fly whereas humans can use them to lift and manipulate objects. Outline how the bird, bat and human forelimb can be used to illustrate the concept of homologous structures.
[2]
a. (homologous structures have evolved) from a common ancestor
b. divergent evolution/adaptive radiation
c. similarities in forelimb bones (in birds, bats and humans) / description of the similarities in bones
d. different uses/functions
Do not accept (positive) correlation.
