Answer: It is important that we use our natural resources so that we use any bad things for our earth
Explanation:
The term ‘Crossing over’ was used by Morgan and Cattell. It is a process in which there is exchange of chromosome segments between non-sister chromatids of a homologous chromosomes. It occurs during pachytene stage of prophase I of meiosis cell division.
Significance of crossing over:
- Crossing over provides genetic variation in all sexually reproducing organisms.
- It creates new combination of genes or genetic recombination and produces hybrids.
Answer:
It is usually associated with physical growth delays, mild to moderate intellectual disability, and characteristic facial features. The average IQ of a young adult with Down syndrome is 50, equivalent to the mental ability of an eight- or nine-year-old child, but this can vary widely.
Symptoms: Delayed physical growth, characteristic facial features, mild to moderate i...
Other names: Down's syndrome, Down's, trisomy 21
Causes: Third copy of chromosome 21
Risk factors: Older age of mother, prior affected child
Explanation:
Hope it helps
FOLLOW MY ACCOUNT PLS PLS
<h2>
Hello!</h2>
The answer is:
b. 
<h2>
Why?</h2>
The centripetal acceleration or radial acceleration is present when an object is moving to describe a circular path. The centripetal acceleration is always perpendicular to the direction of the velocity and going inwards and towards the center.
The centripetal acceleration can be calculated using the following equation:

From the statement we know that:

So, calculating we have:

So, the correct answer is:
b. 
Have a nice day!