Answer:
Zygote
Explanation:
As a result of meiosis in the male and female sex organs of a plant, male and female gametes or male and female sex cells produced respectively. Gametes are universally haploid. Male and female gametes fuse or fertilize to form a diploid zygote. A zygote or fertilised egg is a one-celled structure which later develops into an embryo.
<span>They indicate many forms of hominins spent considerable time in trees.</span>
Answer:
Which of the following mechanisms is used by gram-negative bacteria to cross the blood-brain barrier? D) Inducing TNF
Explanation:
The blood brain barrier is a barrier formed by brain microvascular endothelial cells, astrocytes and pericytes. Pathogens can cross this barrier by using different mechanisms. The Tumor Necrosis Factor (TNF) is the way gram-negative bacteria cross this mentioned blood-brain barrier.
When we talk about evolution we come across the process of natural selection. Genetic variation is always required for the natural selection. A change or variation in the genes may help the individuals in a population to better adapt to the environment. Such changes may be brought by mutations or random mating in the population. Such variations help in the survival of the population by allowing them to adapt to changing environmental conditions.
