Answer: Genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).
By the end of meiosis, the resulting reproductive cells, or gametes, each have 23 genetically unique chromosomes. The overall process of meiosis produces four daughter cells from one single parent cell.
Explanation:
During meiosis, homologous chromosomes (1 from each parent) pair along their lengths. The chromosomes cross over at points called chiasma. At each chiasma, the chromosomes break and rejoin, trading some of their genes. This recombination results in genetic variation.
Answer:
Option 1, Robotic arms used aboard the ISS are now used in delicate surgeries on Earth.
Explanation:
The robotic arm on the international space station is used in conducting surgery. The first space robotic arm was launched in 2001 and its name was “Canadarm 2”. Though the aim of this arm was to construct space station but now a days it is used in imaging the surgical work area and instruments through its camera. The best feature of this hand is that it follows the instruction with high efficiency and precision level.
Hence, option 1 is correct.
Answer: B. secrete enzymes that kill bacteria
Explanation:
Paneth cells, so-called because they were first described by Dr. Josef Paneth in 1888, are pyramidal cells, with the nucleus in the basal position, and with large granules in the apical position. Its first isolated specific product was the lysozyme, a bactericidal substance, by Alexander Flemming. These cells play an important role in innate immunity in the small intestine, producing a wide diversity of antimicrobial peptides and enzymes such as lysozyme itself, cryptidines, defensins and a lectin with bactericidal properties.
Wild boars were brought to the United States by humans.Wild boars have quickly spread through the United States.Wild boars have established successfully in areas with warm climates.<span>Wild boars have a high reproductive rate and no natural predators. the answer is (c)
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It is called a Punnett Square
