Answer:
A: True
Explanation:
both of these are examples of passive transport :)
Answer:
When patient takes in antibiotics the resistance bacteria gets a competitive survival advantage over the normal sensitive bacteria and hence grows faster.
Explanation:
- Bacteria can acquire resistance by taking in plasmids containing MDR (Multi-Drug Resistance) gene cassettes. The MDR genes produces proteins that can:
- Render the antibiotic ineffective to act on its target by inducing chemical modifications on the drug.
- Promote efflux of the drug from the bacterial cell so that the drug cannot act upon its target.
- When a healthy person ( having no prior exposure to the antibiotic) is infected by bacteria ( both sensitive and resistant varieties):
- A competition develops for the host cells and nutrients between the sensitive and the resistant variety.
- This mutual competition restricts either of the sensitive or resistant bacterial strain to grow profusely.
- When a person (having prior antibiotic exposure), gets infected by bacteria ( both sensitive and resistant varieties) and is exposed to the same antibiotic:
- The sensitive variety, due to its sensitivity towards the drug, gets killed.
- The resistant variety, due to its MDR genes, bypasses the lethal effect of the drug and survives.
- These surviving resistant bacteria can now infect all the available host cells and utilise all the available nutrients without facing any competition and multiply rapidly.
Explanation:
Fertilization, pictured in Figure 24.23a is the process in which gametes (an egg and sperm) fuse to form a zygote. The egg and sperm each contain one set of chromosomes. To ensure that the offspring has only one complete diploid set of chromosomes, only one sperm must fuse with one egg. In mammals, the egg is protected by a layer of extracellular matrix consisting mainly of glycoproteins called the zona pellucida. When a sperm binds to the zona pellucida, a series of biochemical events, called the acrosomal reactions, take place. In placental mammals, the acrosome contains digestive enzymes that initiate the degradation of the glycoprotein matrix protecting the egg and allowing the sperm plasma membrane to fuse with the egg plasma membrane, as illustrated in Figure 24.23b. The fusion of these two membranes creates an opening through which the sperm nucleus is transferred into the ovum. The nuclear membranes of the egg and sperm break down and the two haploid genomes condense to form a diploid genome.
I believe the answer your looking for is Scientific Theory
The process by which new species are formed
