The invention of the microscope allowed the first view of cells. English physicist and microscopist Robert Hooke (1635–1702) first described cells in 1665. He made thin slices of cork and likened the boxy partitions he observed to the cells (small rooms) in a monastery.
        
             
        
        
        
<h2><u>
Full Question:</u></h2>
In the family tree below, people with the recessive trait of attached earlobes are shaded gray.
What must be true about the person labeled "A"?
A. It is a male with at least one dominant allele.
B. It is a male with two dominant alleles.
C. It is a female with at least one dominant allele.
D. It is a female with two dominant alleles.
<h2><u>Answer:</u></h2>
Its a male with atleast one dominant allele. 
Option A. 
<h3><u>Explanation:</u></h3>
The gene for the attached earlobe is recessive while the gene for the free earlobes is dominant. In the phylogenetic tree, we can see that both the father and mother aren't having attached earlobes. So both of them are having atleast one dominant allele which makes them have free earlobe.
In the F1 offsprings, one of the female and a male is having free earlobes. So both of them have atleast one dominant allele. The 2nd female is having an attached earlobe. So both the recessive allele have come form one parent each. So both of them are heterozygous.
Thus, the male marked as A atleast have one dominant allele. He can be a homozygous dominant, but the probability is 25%. 
 
        
        
        
There are different kinds of tides. This change occur because  when the gravitational pull of the sun works along with the gravitational pull of the moon on Earth, it leads to the oceans bulging out. 
- This result above makes the high tides as been little higher and low tides been little lower than normal.
Spring tides are known to be the deepest as oceans levels are highest in this kind of tide. The neap tides are known to be the shallowest. 
This often occurs when the moon, earth, and sun are said to be at a right-angled plane.  Therefore, the gravitation pull of the moon and sun on the oceans do counteract each other making its net effect is smaller.  
Learn more about Tide from
brainly.com/question/1133278