In the maternity ward, Mrs. Bright and Mrs. Light share a room. When they were ready

Papessa [141]

Answer:

To verify you have a pure sample use the sterile needle to isolate and grow on a new streak plate to make sure you see only one culture.

Explanation:

6 0

2 years ago

GIVING BRAINLIEST!!!! PLS HELP!!!!!! ;-;

lana66690 [7]

Answer:

D) The porcupine is showing a physical characteristic adaptation and the opossum is showing a behavioral adaptation.

Explanation:

Adaptation, which refers to the ability of an organism to adjust to changes in their external environment in order to survive, is of different types namely: physical/structural, behavioral etc.

- A physical or structural adaptation is a possessed physical characteristics/traits of an organism that enables it adapt.

- A behavioral adaptation is an organisms change in behavioral pattern or responses made to changes in the environment.

According to this question;

- A porcupine is said to have quills on its back which helps protect it from predators. This shows an example of STRUCTURAL or PHYSICAL ADAPTATION, which is the QUILLS it possesses.

- An opossum is said to pretend to be dead and become stiff when threatened. This is an example of BEHAVIORAL ADAPTATION because the opossum responds behaviorally to being threatened.

4 0

3 years ago

Read 2 more answers

What is the point of DNA replication

Degger [83]

Answer:

DNA replication is the process by which a double-stranded DNA molecule is copied to produce two identical DNA molecules. Replication is an essential process because, whenever a cell divides, the two new daughter cells must contain the same genetic information, or DNA, as the parent cell

Explanation:

DNA replication is the biological process in which two identical copies of DNA are produced from one original DNA molecule.

The steps involved in the process of DNA replication are as follows:

The first step in DNA replication is to ‘unzip’ the double-helix structure of the DNA molecule.

This is carried out by an enzyme called helicase which breaks the hydrogen bonds holding the complementary bases of DNA together (A with T, C with G).

The separation of the two single strands of DNA creates a ‘Y’ shape called a replication ‘fork’. The two separated strands will act as templates for making the new strands of DNA.

One of the strands is oriented in the 3’ to 5’ direction (towards the replication fork), this is the leading strand. The other strand is oriented in the 5’ to 3’ direction (away from the replication fork), this is the lagging strand. As a result of their different orientations, the two strands are replicated differently.

A short piece of RNA called a primer (produced by an enzyme called primase) comes along and binds to the end of the leading strand. The primer acts as the starting point for DNA synthesis. DNA polymerase binds to the leading strand and then ‘walks’ along it, adding new complementary nucleotide bases (A, C, G and T) to the strand of DNA in the 5’ to 3’ direction. This replication is continuous. Numerous RNA primers are made by the primase enzyme and bind at various points along the lagging strand.

Chunks of DNA, called Okazaki fragments, are then added to the lagging strand also in the 5’ to 3’ direction. This type of replication is called discontinuous as the Okazaki fragments are joined up later.

Once all of the bases are matched (A with T, C with G) an enzyme called exonuclease strips away the primer(s).

The new strand is proofread to make sure there are no mistakes in the new DNA sequence.

Finally, an enzyme called DNA ligase seals up the sequence of DNA into two continuous double strands.

The result of DNA replication is two DNA molecules consisting of one new and one old chain of nucleotides. This is why DNA replication is described as semi-conservative, half of the chain is part of the original DNA molecule, half is brand new.

Following replication, the new DNA automatically winds up into a double helix

(b) DNA replication occurs in S phase of cell cycle in eukaryotes. If cell division is not followed after DNA replication then the replicated chromosomes (DNA) would not be distributed to daughter nuclei. A repeated replication of DNA without any cell division results in the accumulation of DNA inside the cell nucleus, leading to polyploidy.

7 0

2 years ago

Which cell structure is the gatekeeper, controlling what goes in and out of the cell?

katen-ka-za [31]

<span>The cell membrane acts as the gatekeeper of the cell, determining what goes in and out.</span>

7 0

3 years ago

If humans change the function or equilibrium of one of Earth's systems, this will not change

joja [24]

Answer:

False.

Explanation:

All of the things found in the Earth system can be categorized into four (4) main categories and these includes;

I. Land: this subsystem forms a sphere which is generally referred to as litosphere.

II. Water: this subsystem forms a sphere which is generally referred to as hydrosphere. It comprises of landforms such as mountains, valleys, plateaus, ridge, rocks, etc.

III. Air: this subsystem forms a sphere which is generally referred to as atmosphere. This sphere comprises of gases such as oxygen, carbon dioxide, nitrogen, etc.

IV. Living organisms: this subsystem forms a sphere which is generally referred to as biosphere. It comprises of all living things such as humans, animals and plants.

If humans change the function or equilibrium of one of Earth's systems, this will significantly change the function or equilibrium of all of Earth's systems. Consequently, these changes result in environmental phenomenon such as volcanoes, earthquakes, tornadoes, wildfire, etc.

6 0

3 years ago