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 :Four characteristics were to be used for the classification of all viruses:
Nature of the nucleic acid in the virion.
Symmetry of the protein shell.
Presence or absence of a lipid membrane.
Dimensions of the virion and capsid.
Explanation:
When the concentration o molecules inside a cell is different form the concentration of molecules outside a cell, we can either call it hypertonic or a hypotonic solution, and the difference between the two concentrations is called a concentration gradient.
Hypertonic - name given to a solution that has a bigger concentration than the concentration in a cell.
Hypotonic - name give nto a solution that has a smaller concentration than the concentration in a cell.
Hope it helped,
BioTeacher101
B. mass extinctions happen when populations crash due to overpopulation while background extinctions are more likely to result from disease.
