Question

1. a) what is an evolutionary constraint? b) what are three constraints on arthropods? 28. why does molting limit an arthropods size? 29. how does strength limit the arthropods size? 30. a) how do insects get oxygen? b) how does this limit their size?

Explanation:

a) An evolutionary constraint is a factor that limits the ability of a species to evolve in certain ways. It can be due to genetic, developmental, or environmental factors.
b) Three constraints on arthropods could include: 1) Molting - the process of shedding exoskeleton can be risky and energy - consuming. 2) Oxygen diffusion limitations in their respiratory systems. 3) Mechanical limitations of their exoskeleton and appendages for larger sizes.
For question 28, molting limits an arthropod's size because the new exoskeleton is soft and vulnerable, and larger arthropods are more exposed during this time. Also, the energy cost of producing a larger exoskeleton during molting can be prohibitive.
For question 29, strength limits the arthropod's size as the exoskeleton and muscles need to support the body mass. As size increases, the ratio of surface - area to volume changes, and the strength of the exoskeleton and muscles may not be sufficient to support a very large body.
For 30a, insects get oxygen through a system of tracheae that branch throughout their bodies and open to the outside via spiracles.
For 30b, this limits their size because oxygen diffusion becomes less efficient over longer distances. As insects get larger, it becomes more difficult to supply oxygen to all parts of the body through this passive diffusion - based system.

Answer:

1. a) A factor limiting a species' evolution.

b) Molting, oxygen diffusion, mechanical limitations.

1. New exoskeleton is soft and molting is energy - costly.
2. Exoskeleton and muscle strength may not support large body mass.
3. a) Through tracheae and spiracles.

b) Oxygen diffusion is less efficient over long distances.