Develop diseases because they have little genetic variation.
THE EXCRETORY SYSTEM
Answer: The attachment shows the nephron which is the functional unit of the kidney.
It does the work of urine formation through 3 distinct processes.
-Ultra filtration( Small molecules are forced out of the selectively permeable membrane of the glomerulus into the Bowman's capsule under regulated pressure.these molecules are from the blood in the glomerulus brought in by the afferent arteriole.
- Selective reabsorption ( Useful molecule and iron such as glucose and sodium are reabsorbed back into the blood as the filtrate flows through the tubule(nephron)
-Tubular Secretion. ( Movement of molecules not filtered by the glomerulus during the initial stage of filtration back into the filtrate through the renal capillaries.
Stella's urine sample shows the presence of large protein (ULTRAFILTRATION)
John's blood test report indicates a high toxin level ( ULTRAFILTRATION AND TUBULAR SECRETION)
Miguel's blood test shows an increase in metabolic waste( ULTRAFILTRATION AND TUBULAR SECRETION)
Janice's urine report shows the presence of vital materials ( SELECTIVE REABSORPTION).
Answer:
Explanation:
Meiosis is a form of cell division that occurs in the sex cells of organisms. It ensures the reduction of a diploid cell to an haploid cell to allow for the formation of a diploid zygote after fertilization (contribution of both parents haploid sex cells to give a diploid zygote). Thus, this process is very essential and important.
The reduction is accomplished by 2 divisions after the duplication of chromosomes
- first division: separation of homologous pairs of chromosomes (this reduces the total in half)
- second division: separation of sister chromatids of a chromosome.
The rearrangement in meiosis occurs by crossing over/genetic recombination.
This is the exchange of genetic material between homologous pairs of chromosome bringing about a rearrangement and genetic variation
An example of a chromosomal abnormality that arises as a result of defects in this process is the Down Syndrome which is caused by a nondisjunction of the chromosomes 21 pair in a sex cell.
This condition produces offsprings that have some characteristic facial features, short stature etc
The CNS involves the brain and spinal cord and the PNS involves the body nerves.
Answer:
B
Explanation:
When deforestation takes place, it heats up the atmosphere causing more global warming.
