Answer:
500-million-year-old fossil found in BC is ancient ancestor of spiders and scorpions. Palaeontologists in British Columbia have found a fossil of the oldest known ancestor of scorpions and spiders.
Answer :
The animals are categorized into 2 groups - eukaryotes and prokaryotes. The microbes like bacteria are coming under prokaryotes. They are unicellular organisms and without a true nucleus.
Viruses are the connecting link between the living and non - living. They are smaller than bacteria. The microbes less than 100 micrometer can't be seen by the naked eye. They can only visible under a microscope.
Viruses like polio, flu virus sizes are 10nm. But some of the viruses are also less than 10nm. The size of bacteria is 1 micrometer. The viruses are 10 times smaller than the bacteria.
The eukaryotic organisms are more advanced and multicellular. Their cell size is larger than bacteria and viruses. The red blood cells under the light microscope are 8 micrometers. The typical animal cells like sperm are 60 micrometers and a skin cell is 30 micrometers. The plant cell for example pollen is 90 micrometers.
The eukaryotic cells sizes are more than prokaryotes like bacteria.
Answer:
each of the two daughter DNA molecules contains one strand from the original DNA molecule and one newly synthesized strand.
Explanation:
DNA replication is a semi-conservative process. The two parental DNA strands are separated from each other by the action of helicases. The separated DNA strands serve as the template. Primase enzyme forms primers which are elongated by DNA polymerase enzymes. These enzymes elongate the primer by the addition of deoxynucleotides complementary to the sequence of the template DNA strand.
Therefore, DNA replication forms two DNA double helices from one parental DNA molecule. Each of the daughter DNA molecules contains one parental DNA strand and one newly formed DNA strand making the process semi-conservative.
Genes close to each other- Strongly Linked genes
Genes on different chromosome- unlinked genes
Genes apart from each other,but on same chromosome- linked genes
Explanation:
Linkage is defined as the tendency of genes located on same chromosome to be inherited together.
Genes located on different non-homologous chromosome are called unlinked genes.
Genes located on same chromosome are called linked genes.
Genes located close to each other are strongly linked as tend to show complete linkage.
Genes located on different chromosome tend to show incomplete linkage.
Molecular Biology-
Comparative Anatomy- 5
Phylogeny- 2
Homologous Structures- 1
Vestigial Structures- 3
Analogous Structures- 4
