We share 50% of our DNA with trees, 70% with slugs (gross), 44% with honey bees, and even 25% with daffodils.
Answer;
Primitive streak.
At the onset of the embryonic period, the primitive streak appears. It will eventually become the neural tube.
Explanation;
The primitive streak is a transient structure which forms on day 15 of human development.
It marks the start of gastrulation; the process in which the inner cell mass in converted into the trilaminar embryonic disc.
It originates from the anterior epiblast.
<span>The immune system is the body's natural defense mechanism against organisms that can cause infection.There are three types of mechanisms:
1. Cellular :</span><span> refers to the recognition and/or killing of virus and virus-infected cells by leukocytes and the production of different soluble factors (cytokines) by these cells when stimulated by virus or virus-infected cells
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2. Structural: </span>barriers and the immune system defend the body<span> against organisms that can cause infection. </span>Natural<span> barriers include the skin, mucous membranes, tears, earwax, mucus, and stomach acid.
3. Chemical: </span><span>Some of these include the low pH of the stomach, which inhibits the growth of pathogens; blood proteins that bind and disrupt bacterial cell membranes; and the process of urination, which flushes pathogens from the urinary tract.
</span><span>antibodies - chemical
tissues lining hollow organs - cellular
phagocytes - cellular
skin - structural
antigen - chemical
leukocytes - cellular</span>
Answer:
Since sexual reproduction requires two individuals, it allows intermingling of genes which is beneficial for the individuals as well as the entire species. The organisms produced by asexual reproduction are genetically identical to each other. ( I hope it helps )
The type of joint that allows bones to move backward and forward in only one direction is the hinge joints. Ball and socket are the joints that allows movement in all directions. Gilding joints are type of joints that are the vertebral disks that allow twisting, turning, and sliding. Hinge joints are formed between two or more bones where the bones can only move along one axis to flex or extend. They include the ankle, elbow and knee joints.
