Answer:
Option D, A subject is observed both before and after two exposures to the treatment.
Explanation:
In A-B-A-B design the alphabets have following meaning
a) First A – It is the baseline value or the value measured before treatment
b) First B – It is the treatment measurement
c) Second A - It is the withdrawal of treatment
d) Second B – It is the reintroduction of treatment
The second A is known as the reversal phase in which the intervention is withdrawn to see if the target behavior returns to the baseline behaviour
Thus , there are two measurements involved one before the intervention and second after the intervention
Option D is correct
Muhammad Divided the first Islam empire
Answer:
Abnormal BRCA1 and BRCA2 genes are found in 5% to 10% of all breast cancer cases in the United States. A study found that women with an abnormal BRCA1 gene had a worse prognosis than women with an abnormal BRCA2 gene 5 years after diagnosis.
Explanation:
Answer:
Meiosis is a type of cell division that reduces the number of chromosomes in the parent cell by half and produces four gamete cells. This process is required to produce egg and sperm cells for reproduction. So basically saying, C is the right answer.
Explanation:
Answer:
Seaweeds, shrimps, salmon
Explanation:
The rapid increase in the human population day by day has led to the increased usage of marine plants and animals. Due to this, the population f some marine plants and animals is declining to threatening levels.
To overcome his problem, scientists have devised the method of mariculture. This technique involves raising aquatic plants and animals in artificial lakes or ponds containing salty water just like in the oceans.
Some of these plants and animals are:
- Sea weeds: People might think that they do not consume sea weeds but it is actually present in most of our daily use products like toothpaste, ice creams and even in some automobiles. Many people from the world consume sea weeds as food. Hence, they are being raised in maricultures.
- Shrimps: Shrimps are favourite sea food among many people belonging to different areas. Hence, there population is declining due to which they need to be raised artificially.
- Salmon: The salmon is a kind of fish common to almost every nation. Hence, to meet the demands of people they need to be produced in maricultures.
