Ferns
<span>
Hornworts, mosses and liverworts do not have vascular tissue. They are considered in the division Byrophyta, none of which contain vascular tissue. Ferns are a step up in complexity in the division Pteridophyta, the first plants which contain vascular tissue. </span>
<span>The layer most likely to have organisms which lived at the same time as the bird species is 'C', Layer 2. Layer 2 is closer to layer 3 than any of the other layers listed. Assuming that layers were laid down sequentially as time passed, it is reasonable to assume that layer 2 was laid down most closely in time to layer 3.</span>
Answer:
By performing a test cross i.e. a cross with a recessive trait
Explanation:
According to the question, hairlessness is a recessive trait, meaning that it will only be expressed in a homozygous condition i.e. when there are two recessive alleles in the genotype. Presence of hair is dominant, meaning that it will mask the phenotypic expression of hairlessness allele in a heterozygous state. Hence, a dominant phenotype can either be homozygous (same dominant allele) or heterozygous (combination of dominant and recessive alleles).
In order to determine which of these genotypes the dominant phenotype possess, we perform a test cross. A test cross is a cross performed to determine the genotype of the dominant organism by crossing it with a homozygous recessive genotype.
Ideally, the offsprings resulting from the cross will all be phenotypically dominant if the organism in question is homozygous dominant but if the organism is heterozygous dominant, the offsprings will occur in an equal ratio of dominant to recessive phenotypes.
So in this case, all of offsprings of this cross between the rat terriers will possess hair if the dominant rat terrier dog is homozygous, but if the dominant rat terrier dog is heterozygous, an hairless offspring will be produced.
Answer:
A. Actin filaments and microtubules
B. intermediate filaments
Explanation:
Actin filaments and microtubules are two major building blocks that form part of the cytoskeleton in all eukaryotic cells. Both actin filaments and microtubules play a fundamental role in the dynamics of the cytoskeleton, and they are involved in many essential cellular processes including, among others, mitosis, cytokinesis, intracellular transport, cell signaling, etc. Moreover, intermediate filaments are very stable structures found in animal cells, where they extend from a ring around the cell nucleus to the plasma membrane in order to provide consistency and shape to the nuclear envelope.
Answer:
Instable behavior.
Explanation:
The checkpoints currently behaving instable in sally cancer cells because mutants show genetic instability so this instability is the cause of cancer disease. Two checkpoints are sensitive to DNA damage, one occur before mitosis cell division and the other occur before replication of DNA. So damage occur in these two check points leads to instable behavior of cancer cells.
