Answer:
Cyanobacteria, Anabaena and Azotobactor are called Nitrogen fixing bacteria. These bacteria change the nitrogen in the atmosphere into a form that is used by the plants to make proteins. Plants take nitrogen in the form of nitrates. The atmospheric nitrogen is first converted into ammonia after that ammonia is converted into nitrates and this nitrates use by the plants to make proteins.
The science is very important in the evolution and the improvement of the lifestyles of the human being. The researches in the sciences help in providing conclusions, which are helpful in day to day life. The technologies and innovations make life easier by providing various tools and techniques. Also, the researches in the science provide chance to improve lifestyle by providing scientific knowledge to improve the ethics, education, justice, aesthetics etc.
Answer:
Explanation:
La fecundación es el proceso por el cual dos gametos (masculino y femenino) se fusionan durante la reproducción sexual para crear un cigoto con un genoma derivado de ambos progenitores. Los dos fines principales de la fecundación son la combinación de genes derivados de ambos progenitores y la generación de un cigoto.
En el caso de las plantas con semillas pros, hay que diferenciar el fenómeno de la fecundación propiamente dicho (unión íntima de dos células sexuales hasta confundirse sus núcleos respectivos y, en mayor o menor grado, sus citoplasmas),1 del proceso biológico que lo antecede: la polinización, en el que los granos de polen, desarrollados en las tecas que contiene cada antera de un estambre (hoja reproductora masculina), son transportados por el viento o los insectos a los estigmas, donde germinan emitiendo un tubo polínico que crece hacia el ovario. En este caso no se trata de gametos, sino de esporas, pues cada grano de polen contiene dos gametos o células reproductoras masculinas
Answer:
The answer is: a. Climacteric
Explanation:
Climacteric is the time in the midlife of a woman that starts with the diminution in ovarian activity (less production of estrogen and progesterone) until the end of ovarian function. It is the compilation of gradual changes of ovarian function that happen before the menopause (cessation of menses) and continue for a while.
The phases of the climacteric are pre-menopause, menopause and post-menopause. During the pre-menopause, hormonal changes will take place, there is a decrease in estrogen and progesterone production.
