Photoreceptors<span>: The light sensing nerve cells (rods and cones) </span>located<span> in the retina. Pupil: The adjustable opening at the center of the iris through which light enters the</span>eye<span>. Retina: The light sensitive layer of tissue that lines the back of the </span>eye<span>.</span>
Answer:
C
Explanation:
The brother has different alleles for the blood type gene than his sister does. Blood type is inherited from parents like many other traits that can be displayed on a punnet square. Depending on what the parents blood type alleles were, the brother and sister could have different blood types.
A different number of chromosomes doesn't lead to different blood types, so D is wrong. And A is incorrect because the number genes also does not affect blood type. And I think the blood type genes are on the same chromosome, so B is wrong. C is correct because blood type is inherited by alleles, and different alleles can cause different traits, such as blood types.
The generally widely accepted first step of the scientific method is to ask a question.
This is where you think of a question which you want to do an experiment on, and then later on conduct an experiment to answer that question.
Answer:
The correct order, from fastest to slowest, for the passage of molecules and ions through the cell membrane is oxygen, sodium ions, glucose (option D).
Explanation:
The plasma membrane is a lipid bilayer, with glycoproteins and membrane proteins, which constitutes a semi-permeable barrier to the passage of substances into and out of the cell.
The speed with which a substance can pass through the membrane depends on its chemical properties -hydrophilic substances pass through with greater difficulty than lipophilic ones- requiring in some cases specialized transport mechanisms. The different rates with which a substance passes depends on this.
- <em>Oxygen (O₂) </em><em>passes through simple diffusion, depending on a concentration gradient. It's the molecule that passes through the membrane the fastest.
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- <em>In second place, there would be the </em><em>Na⁺ ions</em><em> -charged atoms- that cross the membrane by facilitated diffusion, through specific ionic channels.
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- <em>The </em><em>glucose</em><em> molecule, being larger, requires the use of transport proteins, being its passage through the membrane slower with respect to oxygen or sodium.</em>
Undoubtedly, molecular weight and affinity for the plasma membrane are determining factors for the passage of molecules through the lipid bilayer.
Learn more:
Simple diffusion and active transport brainly.com/question/6420224