Looking at the onion root tip under the microscope you can see large, rectangular cells with visible distinct cell walls surrounding it (cells have a more regular shape because of the wall). Inside the cells, you can notice darkly stained nucleus, large vacuoles at the center and sometimes small granules within the cytoplasm. Looking the onion root tip under the microscope is often the way to observe mitosis. Usually, you cannot see organelles such as mitochondria, ribosomes, rough and smooth endoplasmic reticulum, centrioles and Golgi body as they appear translucent and because are too small to be seen under the light microscope (electron microscope required). Also, chloroplasts are not present in an onion cell because it is not a photosynthetic cell.
Epithelial tissue lines the cavities and surfaces of organs and blood arteries throughout the animal body, whereas connective tissue supports, links, and divides many types of tissues and organs in the body. This is the main distinction between epithelial and connective tissue.
Cell arrangement: The physical properties of the Epithelial tissue affect how the connective tissue is organized. There are different arrangements of epithelial cells, such as squamous, cuboidal, and columnar, that organize as simple, stratified, pseudostratified, and transitional. Since epithelial cells form from ectoderm, mesoderm, and endoderm, this explains why epithelia line body cavities. Dense irregular connecting tissue is made up of messily organized tightly packed collagen bundles.
Learn more about Epithelial tissue
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Answer:
a) snRNA
Explanation:
The association of small nuclear RNA (snRNA) and some specific proteins forms small nuclear ribonucleoprotein complexes. Some complexes are spliceosomes, molecular machines -made up of a snRNA and about 80 proteins- that remove introns from pre-mRNAs via successive phosphoryl transfer reactions.
The round-seed allele would be termed as dominant. A dominant allele is always expressed. The non-dominant allele, or the recessive allele is overshadowed by the dominant. So in this case, the recessive allele would be the wrinkled-seed allele and the dominant one is the round-seed allele.
