Answer:
Mitosis is a division of a eukaryotic cell in which the chromosomes are evenly distributed among the daughter cells.
In multicellular organisms, both sexual and asexual reproduction is followed by cell division, which ensures the growth and development of the organism. In addition, cell division is necessary to replace dead cells and repair injuries. New cells are constantly being added and old ones are being destroyed. About a hundred thousand more cells are created every second, and of course the same number dies. The new cells start with the division of the source cell. The cells formed in this way are called daughter cells. Stem cells can gradually divide into all the different cells in the body through mitosis.
Most of the body's cells are constantly renewed by mitosis, but there are also so-called irreplaceable cells that are formed only once in a lifetime for the life of the organism and do not regenerate by mitosis.
Complete question: A phylogenetic tree shows that birds and crocodiles share many features. A hypothesis based on this tree predicts that these features are present in a common ancestor. Which of these predicted traits is supported by fossil evidence?
A) four-chambered heart
B) singing for territory
C) eggs and nests
D) singing to attract mates
Answer: (c) eggs and nests
Explanation:
A hypothesis based on phylogenetic tree shows that birds and crocodiles have ancestral connection. Fossil evidence shows that their common ancestor exhibit oviparity as a means of reproduction (i.e. laying of eggs and embryo develops within the egg), and also housed their eggs in the nest for protection against predators and other important reasons.
Answer:
reflection I took the test
Passive transport<span> is a movement of </span>biochemicals<span> and other </span>atomic<span> or </span>molecular<span> substances across </span>cell membranes through <span>concentration gradients</span><span> without need of </span>energy<span> input. Unlike </span>active transport<span>, it does not require an input of cellular energy because it is instead driven by the tendency of the system to grow in </span>entropy<span>. The rate of passive transport depends on the </span>permeability<span> of the cell membrane, which, in turn, depends on the organization and characteristics of the membrane </span>lipids<span> and </span>proteins<span>. The four main kinds of passive transport are simple </span>diffusion<span>, </span>facilitated diffusion<span>, </span>filtration<span>, and </span>osmosis.
Answer:
a. preventing the cross-linkage of NAM subunits
Explanation:
The bacterial cell wall is made of peptidoglycan which is a polymer of alternating N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM) residues. The NAM residues are crosslinked to impart additional strength to the cell wall.
Most of the antibiotics that target the cell wall synthesis in bacteria inhibit the enzyme of transpeptidation which in turn cross-links the NAM residues of the polysaccharide chains of the bacterial cell wall. Examples of these antibiotics include penicillins and cephalosporins.
