The fact of many different things or people being included in something; a range of different things or people
Diversity definition, the state or fact of being diverse; difference; unlikeness: diversity of opinion
There are several information's of immense importance already given in the question. Based on those information's the answer can be easily deduced.
Initial number of bacteria in the culture = 1000
Number of bacteria after t hours = 1000 (2)^t
Then
1000 (2)^t = 50000
2 ^t = 50
t = 5.6
I hope the procedure is clear enough for you to understand.
The answer for this one is b) Looping of DNA
Answer:
In humans, genetic variations are caused because humans reproduce by a sexual life cycle which is termed as meiosis. In such a life cycle, the offspring receives half the chromosomes from the mother and half from the father. Crossing over and random assortment of chromosomes are two phenomenons which occur during meiosis. Due to these two phenomenons, genetic variations are caused.
During crossing over, the exchange of DNA segments between the homologous chromosomes takes place which brings about the genetic variations.
The answer should be reptiles!
The characteristics of reptiles are:
1. They are four-legged
2. They have an outer covering of scales
3. They breathe with the aid of lungs
4. Although most reptiles lay eggs, some also give birth to live young (fertilise internally)!
I hope this helps! :)