Q: What distinctive dna shape forms when the two nucleotide chains wrap around the same axis? Read this paragraph and choose the correct option from the provided answers: Simple Model of DNA. In this simple model of DNA, each line represents a nucleotide chain. The double helix shape forms when the two chains wrap around the same axis. Choices: - single spiral - chain helix - double spiral - double helix A:
double helix

(Question)
Q: Thrombocytes are more commonly known by what name? Read this paragraph and choose the correct option from the provided answers: Platelets and Coagulation Factors Blood must clot to heal wounds and prevent excess blood loss. Small cell fragments called platelets (thrombocytes) are attracted to the wound site where they adhere by extending many projections and releasing their contents. These contents activate other platelets and also interact with other coagulation factors, which convert fibrinogen, a water-soluble protein present in blood serum into fibrin (a non-water soluble protein), causing the blood to clot. Many of the clotting factors require vitamin K to work, and vitamin K deficiency can lead to problems with blood clotting. Many platelets converge and stick together at the wound site forming a platelet plug (also called a fibrin clot), as illustrated in Figure 40.8b. The plug or clot lasts for a number of days and stops the loss of blood. Platelets are formed from the disintegration of larger cells called megakaryocytes, like that shown in Figure 40.8a. For each megakaryocyte, 20003000 platelets are formed with 150,000 to 400,000 platelets present in each cubic millimeter of blood. Each platelet is disc shaped and 24 m in diameter. They contain many small vesicles but do not contain a nucleus. Choices: - chromosomes - molecules - droplets - platelets A:
(Answer)
platelets

Ques: Q: Diffusion can occur across a semipermeable membrane, such as the cell membrane, as long as a what exists? Read this paragraph and choose the correct option from the provided answers: Diffusion can occur across a semipermeable membrane, such as the cell membrane, as long as a concentration gradient exists. Molecules will continue to flow in this manner until equilibrium is reached. At equilibrium, there is no longer an area of high concentration or low concentration, and molecules flow equally in both directions across the semipermeable membrane. At equilibrium, equal amounts of a molecule are entering and leaving a cell. Choices: - polarity - parity - differential - concentration gradient A:
Ans: concentration gradient

(Q).
Q: What are the rolling motions during an earthquake called? Read this paragraph and choose the correct option from the provided answers: There are two major types of seismic waves. Body waves travel through the Earth's interior. Surface waves travel along the ground surface. In an earthquake, body waves are responsible for the sharp jolts. Surface waves are responsible for the rolling motions that do most of the damage in an earthquake. Choices: - tidal waves - seismic thrusts - velocity waves - surface waves A:
(A).
surface waves

Ques:Q: Also called lodestone, the mineral magnetite is the most powerful what? Read this paragraph and choose the correct option from the provided answers: Some materials are natural permanent magnets. The most magnetic material in nature is the mineral magnetite, also called lodestone (see Figure below ). The magnetic domains of magnetite naturally align with Earth's axis. The picture on the left shows a chunk of magnetite attracting small bits of iron. The magnetite spoon compass shown on the right dates back about 2000 years and comes from China. The handle of the spoon always points north. Clearly, the magnetic properties of magnetite have been recognized for thousands of years. Choices: - material on Earth - synthetic magnet - healing magnet - natural permanent magnet A:

Ans:natural permanent magnet

Ques:Q: An antigen is a macromolecule that reacts with components of what? Read this paragraph and choose the correct option from the provided answers: Figure 42.10 An antigen is a macromolecule that reacts with components of the immune system. A given antigen may contain several motifs that are recognized by immune cells. Each motif is an epitope. In this figure, the entire structure is an antigen, and the orange, salmon and green components projecting from it represent potential epitopes. Choices: - circulatory system - pulmonary system - digestion system - immune system A:

Ans:
immune system