Where can you view pictures of the human ear?

What is unique about Homo erectus compared to previous hominins?

DanielleElmas [232]

Answer: c. It is the first hominin known to have migrated out of Africa.

Explanation:

The Homo erectus were the ancient humans which are considered to be over first relatives which used to have human like body shape, short arms and long legs relative to their torso. The main unique feature about these humans is that these were the first humans which migrate out of the Africa and they were the first humans who starting cooking of food for the first time.

8 0

2 years ago

Calculate the mass defect for oxygen-16 given this data. Round to the 5es001-1.jpg decimal place. mass of an oxygen-16 atom: 15.

Naya [18.7K]

Answer:

Explanation:

Given parameters:

Mass of oxygen atom = 15.994914amu

Mass of a proton = 1.00728amu

Mass of a neutron = 1.00866amu

Unknown:

Mass defect = ?

From the periodic table, the number of the elementary particles in a neutral Oxygen atom is given below:

Number of protons = 8

Number of neutrons = 8

Number of electrons = 8

Solution

The mass defect examines the difference between the actual mass of an atom and sum of masses of the nucleons.

The mass of an atom is concentrated in the nucleus which contains protons and neutrons. Electrons have little to no weight compared with the nucleons.

To calculate the mass defect, we first know the mass of the nucleons first:

1 proton has a mass of 1.00728amu

8 protons will weigh: (8 x 1.00728)amu = 8.05824amu

For the neutrons:

1 neutron has a mass of 1.00866amu

8 neutrons will weigh: (8 x 1.00866)amu = 8.06928amu

Mass of the nucleons = mass of protons + mass of neutrons

= 8.05824amu + 8.06928amu

= 16.12752amu

The mass defect = mass of the nucleons - mass of the atom

= 16.12752amu - 15.994914amu

= 0.132606amu ≅ 0.13261amu to 5 decimal places

6 0

3 years ago

Read 2 more answers

Molecules that are present in the membranes of gram-negative bacteria and are the best known pamps are called ________.

miskamm [114]

Molecules that are present in the membranes of gram-negative bacteria and are the best-known pamps are called Bacterial lipopolysaccharides (LPSs).

Bacterial lipopolysaccharides (LPS) are the primary outer surface membrane elements present in almost all Gram-negative bacteria and it act as extremely strong stimulators of the innate or natural immunity in the diverse eukaryotic species ranging from insects to humans.

Eukaryotes are the organisms whose cells contain a nucleus and other membrane-bound organelles. eukaryote, any cell or organism that possesses a clearly defined nucleus. The first eukaryotic cells was evolved about 2 billion years ago. In this Cells with nuclei surrounded by a nuclear envelope with nuclear pores.

Learn more about lipopolysaccharides (LPSs) here

brainly.com/question/13049342

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4 0

1 year ago

How can you tell that the green sum on a pond is a plant

saw5 [17]

One reason is because of its given color. Typically, Algae or moss grows in saturated areas. The reason it is been is because doc its pigment, or chlorophyll found in its anatomy.

8 0

3 years ago

Which of the statements regarding the cell cycle is true? Group of answer choices It is regulated by cyclins and CDKs. Different

MA_775_DIABLO [31]

Answer:

All of these choices are correct.

Explanation:

Cell cycle is the process of growth and division of cell. It comprises of interphase and mitosis. In interphase the cell grows, replicates its genomic content and prepares itself for division. In mitosis the division occurs.

Cell cycle is controlled by a group of kinases called as Cyclin dependent Kinases (CDKs). They act by phosphorylating their substrates. They are of various types like Cdk1, Cdk2, Cdk4 etc. They become active when they bind to a regulatory protein called cyclin. They are also of various types like Cyclin A, Cyclin B, Cyclin C etc. Level of cyclin and corresponding CDK increases and decreases according to the stage of cell cycle. For example in S phase of cell cycle concentration of cyclin A and E shoots up. CDK2 is able to bind to these cyclin molecules and hence it becomes active.

Cell cycle has major checkpoints where the condition of cell is analysed before it proceeds to the next stage of cycle. If any abnormality is detected, repair mechanism is activated or the cell is killed. Checkpoints do not allow cell cycle to proceed in damaged cells.

p53 is a tumor suppressor protein which can halt cell cycle when it detects some abnormality in cell. It usually acts in G1/S checkpoint (before the DNA replication starts in cell) and G2/M checkpoint (before the cell division begins). Hence, all of the above statements are true.

7 0

3 years ago