A cephalopod is a predatory-like mollusk of the large molluscan class of Cephalopodan animals. This includes cuttlefish, octopus, squid, and/or nautilus. They are animals that live in the ocean. Additionally they eat foods like fish and jellyfish on regular and customary occasions. They sometimes possess cannibalism by eating their own species, which is absolutely crazy. Anyways, I hope that this has helped you today.. :)
Answer:
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a. 4 Cell determination as an issue in the *rest is missing*
b. 4 They assumed that different ways of separating an embryo into two parts would be equivalent as far as the fate of the two parts was concerned.
c. 4 I and III only
Explanation:
The passage demonstrates the importance of two factors in the development of an embryo: cleavage planes of division of embryonic cells and cell differentiation.
Cleavage Planes:
Cleavage basically refers to the division of the zygote into a large number of cells called blastomeres. Cleavage planes are geometrical lines or orientations along which cleavage takes place. Since, all embryonic cells are the precursors of some type of body cells, the cleavage planes determine if the cells are adequate for growth and development.
Cell Differentiation:
Cell differentiation is the transition of an undifferentiated cell into a specialized one. For example, stem cells are undifferentiated cells that develop into progenitor cells that mature into a specific cell lineage. For an embryo to regenerate, the presence of adequate embryonic stem cells is crucial. Embryonic stem cells are present in abundance before the gastrulation phase of embryonic development, after which they rapidly start differentiating.
The plant contains vascular tissue and has an alternation of generation. But, it lacks seeds. So, the plant is a Pteridophyte.
- Vascular tissues are absent in thallophytes and bryophytes. They are found in pteridophytes, gymnosperms and angiosperms.
- The sporophyte and gametophyte generation is common in bryophytes and pteridophytes.
- Seeds are produced in plants that come under the group gymnosperms and angiosperms. The presence of seeds is the main characteristic of these groups.
- Thallophytes, bryophytes and pteridophytes lack seeds. The reproduction in plants that comes under these groups occurs with the help of spores.
Thus, the recently discovered species of the plant should be classified based on the presence of vascular tissues, gametophytes and sporophytes. As pteridophytes contain vascular tissues, sporophytes and gametophytes and lack seeds, the plant is a pteridophyte
Learn more about pteridophytes here:
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Answer:
DNA is a long polymer with a phosphate backbone and deoxyriboses. Adenine, guanine, cytosine, and thymine are the four nitrogenous bases. The backbone of RNA is made up of ribose and phosphate. Adenine, guanine, cytosine, and uracil are four nitrogenous bases.
So DNA is two stranded, RNA is single stranded.
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Explanation:
Answer:
In biology, tissue is a cellular organizational level between cells and complete organs. A tissue is an ensemble of similar cells and their extracellular matrix from the same origin that together carry out a specific function. Organs are then formed by the functional grouping together of multiple tissues.