What can be said about prokaryotes and eukaroytes? A. Eukaryotes always have a cell membrane, but prokaryotes don't.

How do energetic considerations affect the structure of populations? communities? ecosystems?

alexandr402 [8]

<span>10% rule (efficiency between trophic levels): limits how long an ecosystem's food chain can be
Predator/prey cost benefit analysis (i.e. foraging) -- cost is risk of being eaten or killed along the way, benefit is energy/nourishment obtained: limits distribution of predator v. prey
Immigration/Emigration with other populations and ecosystems
Island biogeography: size of land and distance from another population/ecosystem (mainland): limits population size and variability on island</span>

3 0

3 years ago

Organelles. Name them and tell what they are composed of?

VikaD [51]

Nucleus, vacuole, Golgi apparatus, ribosomes, rough endoplasmic reticulum, vacuole, Mitochondria, Smooth Endoplasmic Reticulum, Lysosomes, centriole are the organelles.

Explanation:

Organelles are the membranous cellular structure inside the cell performing specialised functions.

Nucleus: It consists of DNA, the genetic material, chromosome, histone proteins, nuclear envelope.

Vacuole: These are membranous organelles having water, inorganic and organic molecules, waste material and nutrients.

Mitochondria: They have two phospholipid bilayers and proteins, cristae and matrix.

Smooth Endoplasmic Reticulum: It is made up of tubules and vesicles that eventually forms a branch.

Rough Endoplasmic Reticulum: It is composed of tubules, vesicles and cisternae and held by cytoskeleton.

Golgi Apparatus: It has cisternae placed in stacks and lumens, stores the protein to be modified.

Lysosomes: It is composed of lipids and proteins. It has a single layer membrane, lysosome enzyme.

Ribosome: It is made up of rRNA and rProtein.

Centrioles: These are made up of proteins named microtubules.

8 0

4 years ago

Living organisms are classified into six kingdoms. Which of the following are eukaryotes? (The number of answer are 4 in total)

matrenka [14]

Answer:

These are eukaryotes-

Protista
Fungi
Plantae
Animalia

These are prokaryotes-

Archaebacteria
Eubacteria

8 0

3 years ago

One of the grand challenges in biology is understanding how the first cells formed on Earth. Since all cells are bound by a cell

Nezavi [6.7K]

Answer:

The correct answer to the question is: b) Amphipathic molecules.

Explanation:

The membrane structures are composed of molecules having both hydrophobic and hydrophilic regions. These are called Amphipathic molecules.
The hydrophobic region is formed of water insoluble lipid (fatty acid) molecules which tend to avoid contact with water and so remain in the interior of the membrane.
The hydrophilic region is formed by water soluble phosphate groups which forms hydrogen bonds with the water molecules and so remain on the surface of the membrane.
Therefore, a membrane is formed from by a phospholipid bilayer, that is, two layers of phospholipid polymer where the lipid part is directed towards the centre away from water and the phosphate part towards the surface in association with water molecules.
A single phopholipid moiety is composed of a glycerol molecule which forms two ester bonds with a phosphate group and a fatty acid molecule.

7 0

3 years ago

How do consumers/heterotrophs release their energy?*

DiKsa [7]

Answer: Heterotrophs obtain energy by eating plants and animals. Plants are autotrophs, absorbing the sun's energy through photosynthesis and making glucose.

Explanation:

3 0

3 years ago