Question

Define and give examples of convergent evolution

• Use a phylogenetic tree to summarize the evolutionary relationships among vertebrates

• Identify the main characteristics of each major vertebrate group (fish, amphibians, reptiles, birds, mammals)

• List the four types of tissues that occur in all vertebrate bodies and summarize their functions

Answer 1

Convergent evolution is the independent evolution of similar features among species belonging to different time period.

example- The similar nature of the flight or wings of insects ,birds,pterosaurs and birds.

All the four serve the same function and are simmilar in structure but each evolved independently.

a. phylogenetic tree to summarize the evolutionary relationships among vertebrates -

b. Characterstics of fishes -

all fish are cold blooded.

they live in water .

they breathe through gills

they have bladders for swimming

they have fins to do their movement.

characterstics of amphibians -

they have unshelled eggs

they have permeable skin

the adults in amphibians are carnivorous always.

characterstics of reptiles -

they are vertebrate

they reproduce through eggs.

they are ectothermic or cold blooded

they have scales or scutes.

characterstics of birds -

feathers are defining feature of birds

all birds have wings for flight

they have a beak

they lay eggs for reproduction of their young ones.

they have skeleton with light weight bones.

characterstics about mammals-

presence of hair or fur

presence of sweat glands

there are specialised to produce milk,known as mammary glands.

there are three middle ear bones.

there is a 4 chambered heart.

c.four types of tissues found in vertebrates are epithelial tissues ,connective tissues ,muscle tissues and nervous tissues.

function of epithelial tissues - they fotlrm the covering of all the body parts ,line body cavities and hollow organs and are the major tissues in glands. They help in secretion, absorption, excretion,filtration,diffusion and sensory reception.

function of connective tissues - major function of connective tissues is to bind and support ,protecting ,insulating, storing reserve fuel and transporting substances within the body.

Functions of muscle tissues- Main function of the muscles is to help in moving body parts which are the only tissues in the body that has the ability to contract.

Functions of nervous tissues - Primary function of nervous tissues is to recieve stimuli and send the impulse to the spinal cord and brain.