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Which of the following serve as antibodies? carbohydrates lipids nucleic acids proteins

Allisa [31]

The answer is protein

4 0

3 years ago

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Do humans and killer whales reproduce... a.)yes b.)no

jolli1 [7]

Yes humans and killer whales are mammalian so theyy reproduce. I think the alternative it's yes.

3 0

3 years ago

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The following are major steps in the process of endochondral ossification. 1. Blood vessels invade the perichondrium. 2. Osteocl

andrew11 [14]

Answer:

Endochondrial ossification is one of the two major pathways through which the skeletal structure is formed. While the other one, intramembranous ossification, is used to form the flat bones mostly of the skull, face, and others, endochondrial ossification is pretty unique because it depends on the presence of hyaline cartilage as a blueprint during fetal development, to then initiate the process of bone formation.

Endochondrial ossification is the process followed by long bones, like the femur. This ossification process initiates about 6 to 8 weeks into fetal development and it is not finished until adolescence. As such, the correct steps of the process of endochondrial ossification would be:

3. Chondrocytes (cells responsible for the formation of the hyaline cartilage) enlarge and calcify.

1. Blood vessels invade the perichondrium. This perichondrium appears over the hyaline cartilage and covers it before calcification and with the arrival of blood vessels, come osteogenic cells, some of which will mature later on into osteoblasts.

5. The perichondrium is converted into a periosteum and the inner layer produces bone. This happens as the matrix attracts mineral salts and traps them into the matrix. The periosteum is the hard covering of bones and calcification and ossification will continue from the middle of the long bone towards the distal parts.

4. Osteoblasts replace calcified cartilage with spongy bone. This type of bone which emerges as the newly specialized osteogenic cells (osteoblasts) replace the cartilage for it, is specific to the epyphysis of long bones, or the heads, of these bones.

2. Osteoclasts create a marrow cavity. Osteoclasts are the other specialized type of osteogenic cells and their purpose is to digest bone to remodel it. During the skeletal formation of long bones, blood vessels will require spaces where they can interact with the bone tissues, especially the spongy parts, and these spaces are known as the marrow cavities.

6 0

3 years ago

Discuss the events of meiosis, and compare and contrasthow meiosis differs from mitosis.

Arisa [49]

Answer:

Meiosis It is one of the ways of cell reproduction. This process is performed in the cells in the sex cells. It is a process of cell division in which a diploid cell (2n) undergoes two successive divisions, with the ability to generate four haploid cells (n). This process is carried out in two nuclear and cytoplasmic divisions, called first and second meiotic division or simply meiosis I and meiosis II

Explanation:

Phases of Meiosis

Two successive cell divisions occur in meiosis, Meiosis I (Reduction) and Meiosis II (Division). Meiosis produces 4 haploid cells. Meiosis is also known as reduction division.

In Meiosis I, the level of ploidy is reduced from 2n to n while in Meiosis II the "set" of remaining chromosomes is divided into a process similar to mitosis (division). The biggest difference in the process occurs during Meiosis I.

- MEIOSIS I: Prophase I

During mating, a key event occurs in the matching of homologous chromosomes.

- Metaphase I

In Metaphase I the tetrads line the equator of the cell. The spindle fibers "stick" to the centromere of each homologous pair and subsequent events are similar to mitosis.

- Anaphase I

During Anaphase I the tetrads separate and the chromosomes are dragged to the opposite poles by the spindle fibers. The centromeres in Anaphase I remain intact.

- Telophase I

Telophase I is similar to mitosis, except that in the end each "cell" has only one group of replicated chromosomes. Depending on the species, the new nuclear membrane can be formed (or not). Some animals can divide their centrioles during this phase.

Telophase may be absent in some species. If there is, it is followed by an interface called interkinesis; Unlike the mitotic interface, there is no duplication of genetic material since each chromosome already has two chromatids. The other difference is that these sister chromatids are no longer genetically identical, due to the cross-linking phenomenon.

- MEIOSIS II: Profase II

During Prophase II, the nuclear membrane (if formed during Telophase I) dissolves, and the spindle fibers appear, as in the prophase of mitosis. Actually, Meiosis II is very similar to mitosis.

- Metaphase II

Metaphase II is similar to that of mitosis, with chromosomes in the equatorial plane and spindle fibers sticking to the opposite faces of the centromere in the kinetochore region.

- Anaphase II

During Anaphase II, the centromere divides and the then chromatids, now chromosomes, are secreted to the opposite poles of the cell.

- Telophase II

Telophase II is identical to Telophase of mitosis. Cytokinesis separates the cells.

Comparison of Mitosis and Meiosis :

- Mitosis maintains the level of ploidy while meiosis reduces it.

- Meiosis can be considered as a phase of chromosome number reduction followed by a slightly different mitosis.

- Meiosis only occurs in relatively few cells of a multicellular organism, while mitosis is more common.

4 0

4 years ago

Two things a scientist would look for to determine if it were a living organism

Digiron [165]

There are many factors to look for to determine a living organism. such as Nutrition, Reproduction, Sensitivity, Growth, Movement, Respiration, and Excretion.

TBut the most important that you can apply to all living organisms, even viruses are: Reproduction (it use the host to increase their number) and nutrition (it take energy from the host to replicate itself).

8 0

4 years ago