Answer:
<em><u>This is the only phylum of the animal subkingdom Parazoa and represents the least evolutionarily advanced group of the animal kingdom. ... Sponges are the only animals that lack tissues with mass of cell embedded in gelatinous matrix.</u></em>
Answer:
The cutaneous membrane is made of a simple columnar epithelium
Explanation:
Cutaneous membrane is the membrane of the skin. This membrane protects the skin from the physical and chemical damage.
Cutaneous membrane is present on skin and exposed to the external environment. This membrane is made of stratified squamous epithelium and keratinized and consist of the underlying layer of dermis. Hence, the membrane is not made upof simple columnar epithelium tissue.
Thus, the correct answer is option (3).
Explanation:
Genetic variation in offspring during sexual reproduction is caused by
- crossing over
- independent assortment
- randomized fertilization
Further Explanation:
All the genetic information within the eukaryotic cell is stored within the nucleus as helical DNA. This DNA is tightly wound around histones as chromosomes. To produce daughter cells during cell division, the chromosomes (total number of chromosomes (2n)) are copied before the cell splits into two daughter cells. This process is known as mitosis, and occurs in cell division and growth processes. Two new nuclei are formed, along with identical cells. These are the same as the parent cell and the chromosome number (2n) is maintained.
Conversely in meiosis, the number of chromosomes (2n) is halved through meiotic divisions, producing 4 (n) germ cells (sperm or eggs), each containing half the number of chromosomes as its parent cell.
- crossing over: the exchange of segments of chromosome, between non-sister homologous or similar chromatids crossing over happens at chiasmata, the point where non-sister chromosomes are joined.
- independent assortment in metaphase I of meiosis: chromosomes align independently and genes segregate independently into new combinations ...in humans 2n, n = 23, 8 million combinations of chromosomes possible
- randomized fertilization: sperm cells fertilize an ovum to form a zygote. This occurs randomly by chance, to result in a complete set of chromosomes 2n, that is a novel combination of half each parent's number of chromosomes
Learn more about mitosis at brainly.com/question/4303192
Learn more about transcription at brainly.com/question/11339456
Learn more about DNA and RNA at brainly.com/question/2416343?source=aid8411316
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