Sustainability refers to how a system remains biodiverse and productive over long periods of time. Succession is a series of predictable changes that occur in a community over time. After a fire, volcano, or other disaster, succession enables an ecosystem to recover.
What is Sickle cell anemia?
Sickle cell is an autosomal recessive trait of humans that arises through mutation in normal gene. The gene for this trait is found in recessive form and you need two copies of the gene - one from father and one from mother- to have the trait expressed. If the trait is expressed it causes a disease called sickle cell anemia.
People with the sickle cell anemia disease have red blood cells of crescent or sickle shape. The red blood cells of this shape can cause many complications in body. They get stuck in blood vessels and cause pain. They also die quickly and make a person anemic (pale).
Probability to have a child with sickle cell anemia:
If a mother is normal but a father is carrier for the trait, then the situation will be as:
Here N indicate normal allele, S indicate allele for sickle cell anemia.
Mother ˣ Father
NN NS
Gametes: N N N S
Offspring: NN NS NN NS
50% : Normal
50% : Carrier
0% : Sickle cell anemia
It means that 50 % kids will be normal and 50% will be carrier for the trait and none of the offspring will have disease Sickle cell anemia.
However, those who are carriers can carry the disease to the next offspring if they are married to a carrier or a person with sickle cell anemia.
Answer:
The correct answer is : Hormones in the plant help fruits develop and ripen.
Explanation:
- Development of fruits and its ripening is brought about by a number of plant hormones :
- Auxin - It promotes the cellular growth, both with respect to cell-division and cell elongation. It promotes the cells in the fruit to expand isodiametrically.
- Gibberellic Acid - This hormone delays the ripening of fruits and also prevents senescence. It helps the fruits to acquire enhanced characteristics.
- Cytokinin - Promotes cell division during the development of fruit.
- Ehylene - Promotes the ripening of fruits.
