Biology Answers

When living pancreatic cells were placed in a solution of a red stain called neutral red, the cytoplasm became red. The cells were then removed from the solution of neutral red The red stain in the cytoplasm moved into vesicles, which were exported from the cell, eventually leaving the cell colourless.

Which transport mechanisms could explain how the red stain entered and I

A active transport and facilitated diffusion

b diffusion and exocytosis

C facilitated diffusion and endocytosis

D osmosis and exocytosis

In peas, a gene for tall plants (T) is dominant over its allele for short plants (t). The gene for smooth peas (S) is dominant over its allele for wrinkled peas (s). The genes are not linked. Determine both phenotypic and genotypic ratios for the results of each of the following crosses:

In general, what happens during an oxidation-reduction reaction between two molecules?

In a pea plant that breeds true for tall, what possible gametes can be produced? Use the symbol D for tall, d for dwarf.

A. In a pea plant that breeds true for dwarf, what possible gametes will be produced?

B. What will be the genotype of F1 offspring from a cross between these two types?

C. Assuming that the allele for tall is dominant, what will be the phenotype of F1

offspring from a cross between these two types?

E. What will be the probable distribution of traits in the F2 generation? (Illustrate with a Punnett square).

What are the factors affecting the Hardy-Weinberg equilibrium?

Lysosomes are known as “suicidal bags” because

Parasitic activity

Presence of food vacuole

Hydrolytic activity

Catalytic activity

write an essay and explain the significance of i. Development of a coelom ii. Bilateral symmetry and cephalization iii. Segmentation in the evolution of animal kingdom

certain protein can only act as a catalyst if it is linked with the B vitamin biotin. This protein is called and biotin is its

Membranes are essential components of all cells. 

• Briefly describe the structure of a eukaryotic plasma membrane, identifying at least two component macromolecules and describing what their basic function is within the membrane.

 The plasma membrane protects the integrity of the interior of the cell by allowing certain substances in, while keeping other substances out.

• Summarize the manner in which small molecules are permitted to pass through the membrane ensuring you explain the difference between passive, facilitated, active, and coupled transport by comparing and contrasting them.
• Finally, explain the difference between endocytosis and exocytosis and provide an example of a molecule (remembering to state its function) that is transferred using this method.

2 Explain how global conditions influenced the progression towards bipedal locomotion in early apes in Africa