Answer:
The endosymbiotic theory states that some of the organelles in eukaryotic cells were once prokaryotic microbes.
The answer is speciation by geographic isolation. When the population of a species gets separated due to reasons such as continental drift, mountains, canyons, etc. then each separated group of population may survive and adapt to their respective environment leading to speciation. These barriers do not allow the evolving populations to interbreed initially and over time when they evolve into different species they become completely reproductively isolated.
Answer:
Kidneys : helps in forming urine
Ureter : They are connected to kidney and by peristaltic action transports urine from kidneys to bladder .
Urinary bladder : It is an hollow sac that holds the urine .
Urethra : transports urine from the bladder to outside of the body .
Explanation:
The human excretory system consists of : Kidney ,ureter ,urinary bladder and urethra .The figure is shown below .
Now , as far as functions are concerned we have :
Kidneys : They have excretory units called nephrons that further consist of :
- Bowman's capsule
- PCT (Proximal convoluted tubule )
- DCT (Distal convoluted tubule)
- CT (collecting tubule )
In nephrons urine is formed and via ureter it is transported to a hollow sac like structure called urinary bladder .
This bladder has muscles that cant remain contracted up to longer period )and then voluntary and involuntary it is excreted through urethra .
The process of passing urine is called Micturition .
Answer:
The mouse and shrew bones were common to all three owls so they were not useful in identifying environments. The gopher bones were unique to the great grey owl of Alaska. Gophers are rodents that are successful in areas with soft soil and lots of grass, so the gopher and this owl would be found in the meadows and evergreen forests of Alaska. The bat was unique to the barking owl of Australia. The bat would be found in woodland habitats where there are many trees the bat can hang from. The gull bones were unique to the short-eared owl of Cuba. Gulls are wetland birds, so the gull and this owl would be found in marshes and coastal areas.
Answer:
The theory of plate tectonics states that the Earth's solid outer crust, the lithosphere, is separated into plates that move over the asthenosphere, the molten upper portion of the mantle. ... At convergent boundaries, plates collide with one another.
