Are mixtures pure substances that cannot be changed into smaller substances?

Which are true about forests? Choose all that apply. I. They are home to one-half of the world's people II. Traditional medicine

Alekssandra [29.7K]

Its IV. forests are habitat for two-thirds of terrestrials species....................

4 0

2 years ago

Four major macromolecules in the body

MaRussiya [10]

There are four major classes of biological macromolecules:

carbohydrates.

lipids.

proteins.

nucleic acids.

5 0

3 years ago

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Describe the chemical components of DNA.

Slav-nsk [51]

DNA is composed of nucleotides, which are composed of three parts:

1. A five carbon carbohydrate (pentose)

Pentose is classified as a monosaccharide (simple carbohydrate), and its molecular formula is represented by $(CH_{2} O)n$ . They are water soluble molecules with sweet taste. Monosaccharides may have from three carbon atoms (trioses) to six (hexoses). In DNA is present pentose (5 carbon atoms)

2. A nitrogenous base

Nitrogenous bases are ring-shaped compounds that contain nitrogen in their molecular structure. They are classified into two groups: purines and pyrimidines

The purine bases are adenine (A) and guanine (G). They are larger and contain more than one ring in their structure,.

The pyrimidines, cytosine (C), uracil (U) and thymine (T), are smaller and composed of a single ring.

3. One or more phosphate groups

A phosphate consists of a trivalent anion that contains one phosphorus atom and four oxygen atoms. Its molecular formula is expressed by $(PO_{4} ^{-3})$ .

3 0

3 years ago

What are the differences in their hard parts, distribution, reproduction among phytoplankton of cyanobacteria, diatom, coccolith

Margarita [4]

Answer:

Explanation:

DIFFERENCES BETWEEN HARD BODY PARTS.

•Cyanobacteria have calcified sheaths.

• Diatoms have hard but porous cell wall.

• Coccolithophores have hard body parts.

• Silicoflagellates skeleton is composed of opaline silica.

• Dinoflagellates do not have hard body parts

• Green algae - no hard body parts.

• Brown algae - no hard body parts.

DIFFERENCES BETWEEN DISTRIBUTION

• Cyanobacteria are found almost in every terrestrial habitat on planet.

• Diatoms are found in oceans, freshwater, soil and damp.

• Coccolithophores are exclusively marine.

• Silicoflagellates are found in marine environment.

• Dinoflagellates are both freshwater and marine.

• Green algae grow on objects that do not move such as substrate, rock.

• Brown algae - wide distribution from tropical to polar zones.

DIFFERENCES BETWEEN REPRODUCTION.

• Cyanobacteria - asexually by binary or multiple fission, fragmentation, spore formation.

• Diatom - asexually by cell division through mitosis.

• Coccolithophores - asexually by binary fission.

• Silicoflagellates - asexually

• Dinoflagellates - asexually

• Green algae - sexually or asexually by cell division, fragmentation, spore formation.

• Brown algae - sexually and asexually.

5 0

2 years ago

What does cell theory refer to

zubka84 [21]

Answer:

Cell theory refers to the idea that cells are the basic unit of structure in every living thing. Development of this theory during the mid 17th century was made possible by advances in microscopy. This theory is one of the foundations of biology.

4 0

2 years ago