What was discovered in the 1930s about genes that helped us understand evolution better.

Anyone know the answer for these two plzzzzz tell me

stepan [7]

Answer:

The components of he respiratory system conduct air to the lungs ,such as the trachea (windpipe) which branches into smaller structures called Bronchi . The process of breathing (respiration) is divided into two distinct phases , inspiration (inhalation) and expiration (exhalation).

Explanation:

4 0

3 years ago

As the kidneys filter blood, it is necessary for both fluid and dissolved chemicals in the plasma to be rapidly removed without

ioda

Answer:

Here are the options to complete the question

A. Fenestrated capillaries

B. continuous capillaries

C. sinusoids

D. anastomoses

A. Fenestrated capillaries is our Sure ANSWER

Explanation:

Fenestrated capillaries (is located wherever active capillary absorption or filtration occurs)

The renal glomerulus - a network of capillaries - can be identified as fenestrated capillaries aiding the diffusion of small molecules and small amount of protein into the blood stream.

6 0

3 years ago

What are all the steps in a descriptive investigation?

I am Lyosha [343]

Explanation:

Make an observation about a phenomenon (qualitative and/or quantitative)

Ask a research question.

Hypothesize a possible answer for your question.

Create a procedure to test your hypothesis.

Identify what you are testing.

Identify your control group/experimental group.

7 0

2 years ago

Match the prokaryotic cell structures to the characteristic of life.

djverab [1.8K]

Answer:

1. Nucleoid: Prokaryotes do not have well defined nucleus. Instead, naked DNA or genetic material is found in the these cells which keeps floating freely in the region of cytoplasm called as mucleoid (nucleus-like). DNA carries the genetic information required for growth, development, metabolic activities and reproduction.

Hence, it must match with b. reproduction: DNA ensures that future generations will be similar to parents

2. Cell wall: Cell wall is the outermost layer surrounding the plasma membrane. It is composed of polysaccharides and is found in bacteria, fungi, and plant cells. In bacteria, it is generally composed of peptidoglycans. Antibiotic such as penicillin acts on the cell wall and creates pores in it which kills the bacteria.

Hence, it can be correctly matched with d. homeostasis: taking an antibiotic, such as penicillin, creates holes in the cell wall of some bacteria, so they lose water and die

3. Flagellum: It is a thread or hair like structure which serves the purpose of locomotion in the cells specially in bacteria, protozoa, spermatozoa etc. In bacteria, it helps in moving in the direction of food and moving away from inhospitable environment.

Hence, it can be correctly matched with e. responding to stimuli: move away from a less hospitable environment or towards a more hospitable environment.

4. Pilus: It is a hair like but rigid structure that protrude from the cell surface of the bacteria. It helps in the process of conjugation by forming a conncetion between cell surface of two bacteria.

Hence, it can be correctly matched with a. reproduction: exchanging genetic material in process of conjugation

5. Ribosomes: Ribosomes serve as the site of protein synthesis in the cell. Bacterial ribosomes are composed of two sub-units with sedimentary constant of 50S and 30S.

Hence, it can be correctly matched with c. maintaining homeostasis: protein is needed for enzymes and repairing structures

6. Cytoplasm: It is gel like material found within the cell (excluding nucleus in case of eukaryotes). All the metabolic activities of the cell generally take place in the cytoplasm of the cell.

Hence, it can be correctly matched with f. homeostasis: using energy, all chemical reactions are performed in the cytoplasm

4 0

3 years ago

What would happen to an ecosystem if an invasive

MrRa [10]

Explanation:

the top predator is removed from the delicate balance of any particular ecosystem, there may be disastrous effects for the other plants and animals that inhabit the environment.

When a top predator is removed from an ecosystem, a series knock-on effects are felt throughout all the levels in a food web, as each level is regulated by the one above it. This is known as a trophic cascade. The results of these trophic cascades can lead to an ecosystem being completely transformed. The impacts trickle down through each level, upsetting the ecological balance by altering numbers of different animal species, until the effects are finally felt by the vegetation

When a top predator is no longer present, populations of their herbivorous prey begin to boom. Without a top predator to regulate their numbers, these animals put a great deal of pressure on the existing vegetation that they require for food and can destroy large amounts of plant life, such as grasses and trees. This then causes further problems, such as soil erosion and loss of animal habitat. Eventually, humans are also impacted due to the resulting lack of soil fertility and clean water that depend on these plants.

Another problem involving the loss of vegetation is the competition that is created between herbivorous species. Competition between species for the remaining plant life is high and weaker species lose out to stronger ones, leading to the potential loss of weaker animals, as well as plant species. Increased competition, therefore, leads to a lack of biodiversity. In contrast, top predators often have varied diets, which means they can pursue a new food source if one is running low, preventing the first source from being eradicated completely. This is one of the ways that top predators are able to maintain biodiversity and the balance of an ecosystem.

The presence of a top predator also helps to maintain balance in an ecosystem by influencing the behaviour and movements of its prey through the fear of being caught. Animals that are prey to a top predator will move around in order to avoid it. This prevents plants and animals in any particular area of an ecosystem from being over-consumed, preserving food sources and habitats. In the absence of top predators, this regulation disappears, allowing certain areas of vegetation to be destroyed completely.

6 0

3 years ago

Read 2 more answers