Models are simplified representations of of different complex systems. They also help to study very small or large objects.
Option B, D and E.
Explanation:
Models are very simplified representations of complex systems and organs or structures which are prepared to study those systems by scientists and normal people easily. Many structures of human body like cells or some tissues are very small in structure or microscopic in nature. So studying them are very hard without specific instruments which are not always available. Thus models are made to easily study those structures by scientists and even normal people and students.
<span>The commonly accepted values is 4 Calories per gram of protein and carbohydrate and 9 Calories per gram of fat. Since we have 2 grams of each, a little simple math will do:
2 g * 4 Cal/g + 2 g * 4 Cal/g + 2 g *9 Cal/g = 8 Cal + 8 Cal + 18 Cal = 34 Cal</span>
The statement that best describes ecological succession is that it always occurs in a predictable pattern. The process is also slow. The correct answer is C.
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
Answer:
Spongy or cancellous tissue – the porous, honeycombed material found inside most bones, which allows the bone to be strong yet lightweight.
