What organ absorbs excess water from undigested food prior to its release from the body as a solid waste

What is thought to have caused the mass extinction at the end of the Cretaceous Period?

It was believed that a asteroid hit the Earth (specifically Mexico) when the asteroid hit it caused a freezing darkness due to dust and debris being kicked up by the asteroid . The dust and debris blocked the sunlight causing a temperature drop.

8 0

3 years ago

Cells from a squirrel are considered eukaryotic and bacteria cells are prokaryotic because -

Vadim26 [7]

Answer:

D

Explanation:

Prokaryotic cells have no nucleus, eukaryotic cells do. A squirrel is eukaryotic, therefore it’s genetic material will be stored in the nucleus.

4 0

3 years ago

What living systems have distinct structures and sets of functions? Be sure to refer to class notes for

Murrr4er [49]

Answer:

Cells.

Explanation:

A cell can be defined as the structural, fundamental, biological and functional unit of life. Cells are found in all living organisms because they are the basic unit of life.

Generally, cells have the ability to independently replicate themselves. These cells can be compared to the kind of structures found in a business or factory, where you have different workers performing different functions.

In a cell, the "workers" that perform various functions or tasks for the survival of the living organism are referred to as organelles.

<em><u>Factory worker = Cell organelle.</u></em>

1. Chief executive officer = Nucleus.

The nucleus controls all the activities taking place in the cell and the synthesis of proteins.

2. Power house = Mitochondrion.

The mitochondria provides all the energy required in the cell by transforming energy forms.

3. Maintenance team = Lysosomes.

They are responsible for absorbing materials and breaking the materials taken in by the cells.

4. Functional managers = Chromosomes.

They give sets of instructions for the synthesis of products.

5. Assembly line workers = Ribosomes.

They are involved in the build up of proteins.

6. Assembly line = Endoplasmic Reticulum.

This is where the ribosomes perform their tasks.

7. Security and support = Cytoskeleton.

They help to maintain and support the shape of the cells.

8. Drivers or messengers = Vesicles.

They ensure proteins are properly transported to the right and exact location.

9. Packaging unit = Golgi apparatus.

Prepares the protein for export by chemically tagging them.

10. Gate man/procurement unit = Cell membrane.

It is the wall of the cell and typically controls what leaves and enters the cell.

Hence, cells are living systems that have distinct structures and sets of functions.

8 0

3 years ago

A newly discovered solar system is found 300 billion kilometers from the sun. How many AU does this represent? Show your work.

Aleksandr-060686 [28]

1 kilometer = 6.68 × $10^{-9}$ (<<<AU is in scientific notation here)

To convert 300 billion kilometer (3,000,000,000 km) into AU you must multiply the kilometer by the equivalent of 1 km in AU (6.68 × $10^{-9}$ )

3,000,000,000 × (6.68 × $10^{-9}$ ) = 20.04 AU

Hope this helped!

4 0

3 years ago

PLEASE HELP!! 36 POINTS!!!

Serhud [2]

Answer:

Natural selection can cause microevolution (change in allele frequencies), with fitness-increasing alleles becoming more common in the population.

Fitness is a measure of reproductive success (how many offspring an organism leaves in the next generation, relative to others in the group).

Natural selection can act on traits determined by alternative alleles of a single gene, or on polygenic traits (traits determined by many genes).

Natural selection on traits determined by multiple genes may take the form of stabilizing selection, directional selection, or disruptive selection.

Introduction

We've already met a few different mechanisms of evolution. Genetic drift, migration, mutation...the list goes on. All of these mechanisms can make a population evolve, or change in its genetic makeup over generations.

But there's one mechanism of evolution that's a bit more famous than the others, and that's natural selection. What makes natural selection so special? Out of all the mechanisms of evolution, it's the only one that can consistently make populations adapted, or better-suited for their environment, over time.

You may have already seen natural selection as part of Darwin’s theory of evolution. In this article, we will dive deeper – in fact, deeper than Darwin himself could go. We will examine natural selection at the level of population genetics, in terms of allele, genotype, and phenotype frequencies.

Quick review of natural selection

Here is a quick reminder of how a population evolves by natural selection:

Organisms with heritable (genetically determined) features that help them survive and reproduce in a particular environment tend to leave more offspring than their peers.

If this continues over generations, the heritable features that aid survival and reproduction will become more and more common in the population.

The population will not only evolve (change in its genetic makeup and inherited traits), but will evolve in such a way that it becomes adapted, or better-suited, to its environment.

Explanation:

Here's my notes, i used and got it correct.

5 0

2 years ago