Answer:
Dust bowl resulted from extreme drying and loosening of the soil that resulted in soil erosion by wind. Thus, it can be related that poor agricultural practices like over plowing , over grazing and leaving the land barren are human activities that must have contributed to the dust bowl.
Explanation:
- Dust bowl is referred to a period in early twentieth century when the the American and Canadian prairies faced severe dust storms.
- These dust storms resulted from severe drought and failure of practices to prevent soil erosion.
- Several people and livestock died as a result of choking.
- Over plowing, removal of top soil and small grasses exposed the soil to eroding winds and caused the dust storms.
During the Silurian Period, simple PLANTS began too grow on land and in damp trees
Answer:
<u>4 types </u>of phenotypes with <u>phenotypic ratio 9:3:3:1 </u>will be obtained.
Explanation:
The Punnett square diagram for the cross between mice with genotype BbCc & BbCc is attached.
It is clear from the diagram attached that the <u>phenotypic ratio</u> will be 9:3:3:1
- The following<u> 9 genotypes</u> will show dominant trait for both the characters i.e. characters represented by B & C genes.
BBCC, BBCc, BbCC, BbCc, BBCc, BbCc, BbCC, BbCc, BbCc
- The following <u>3 genotypes</u> will show dominant trait for one character represented by gene B and recessive trait for other character represented by gene C.
BBcc, Bbcc, Bbcc
- The following <u>3 genotypes</u> will show recessive trait for one character represented by gene B and dominant trait for other character represented by gene C.
bbCC, bbCc, bbCc
- The following genotype is the <u>only genotype </u>which will show recessive trait for both the characters represented by gene B & C.
bbcc
Crude density and ecological density are both related but different. Ecological density is the portion of land that a certain species can colonize, where as crude density is the land within the organism's range.
Answer:
A. Because of base pairing, each strand has all the information to serve as a template for the other strand.
Explanation:
Deoxyribonucleic acid (DNA) is a molecule composed of two antiparallel polynucleotide chains. This double helix serves as a template for its own duplication. DNA templating refers to the process by which a portion of the DNA molecule in a single strand is used as a template to be copied by complementarity base pairing. According to base-pairing rules, Adenine (A) always pairs with Thymine, while Guanine (G) always pairs with Cytosine (C). These nucleotide bases are each linked with their complementary base by hydrogen bonding. When base pairs separate, the hydrogen bond acceptor and donor groups of each strand allow the addition of nucleotides and synthesis of new DNA strands, a process catalyzed by specialized enzymes (DNA polymerases).