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:
New allele combinations are acted upon by natural selection.
Explanation:
Recombination may be defined as the process of the exchange of the genetic material between the homologous chromosomes of the non sister chromatid. The combined trait will be visible in the upcoming generation.
The recombination allows the generation of the new genes in the population. These new genes if beneficial for the population will be pass to the next generations. The new allele will be favored by the natural selection and increases the chance of survival of the population.
Thus, the correct answer is new allele combinations are acted upon by natural selection.
Answer:
The correct answer will be option-C
Explanation:
The plant absorbs the sunlight to perform photosynthesis which helps produce the sugar molecule used by the plants.
The plants absorb maximum sunlight at two wavelengths that are red and blue wavelength by chlorophyll and other pigments. The efficiency of photosynthesis is also measured maximum at these two active wavelengths called action spectrum.
In the given question, since the efficiency of photosynthesis has been discussed which could be measured with the production of oxygen and consumption of carbon dioxide. The experiment performed by the Engelmann showed that aerobic bacteria got concentrated in the blue and red wavelengths as the output of the photosynthesis were observed maximum.
Thus, the selected option is the correct answer.
Answer:
Immunity to Small Pox
Explanation:
Over the years, Europeans had built up an immunity to smallpox because many had contracted the disease and still survived. As the population grew children were born with some immunity to the disease. When the Europeans arrived in the Americas, and smallpox spread around the native peoples, the Europeans did not contract the disease because they were immune. However, since the natives were not immune, they slowly died of due just to the disease as well as some parts of the war between the europeans.
