Mammalian fertilization comprises sperm migration through the female reproductive tract, biochemical and morphological changes to sperm, and sperm-egg interaction in the oviduct. Recent gene knockout approaches in mice have revealed that many factors previously considered important for fertilization are largely dispensable, or if they are essential, they have an unexpected function. These results indicate that what has been observed in in vitro fertilization (IVF) differs significantly from what occurs during “physiological” fertilization. This Review focuses on the advantages of studying fertilization using gene-manipulated animals and highlights an emerging molecular mechanism of mammalian fertilization.
Answer:
3. the absence of a cell wall in human cells
Explanation:
Animal cells do not have cell walls. Cell membranes separate the cytoplasm of the animal cells from the surroundings and maintain their interior. Plant cells have cellulosic cell walls. A cell wall surrounds the cell membrane of a plant cell. Cell walls serve to provide structural support and protect plant cells from pathogens. Cell walls also help keep excess water out of cells so they do not burst. Therefore, human cheek cells would not have cell walls while the onion cells would have cell walls made up of cellulose.
I think the answer would be needs. Hope this helps.
Answer:
The fish is sick or its cold or people have C O V I D
Explanation:
Mycoderma aceti uses acetic fermentation to produce ATP
C2H6O+O2-->CH3COOH+H2O
Saccharomyces cerevisae uses alcoholic fermentation to produce ATP
C6H12O6-->2C2H5OH+2CO2
